Cisco IOS XR IP Addresses and Services Command Reference, Release 3.2
Access List Commands on Cisco IOS XR Software
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Access List Commands on Cisco IOS XR Software

Table Of Contents

Access List Commands on Cisco IOS XR Software

clear access-list ipv4

clear access-list ipv6

copy access-list ipv4

copy access-list ipv6

deny (IPv4)

deny (IPv6)

ipv4 access-group

ipv4 access-list

ipv4 access-list log-update threshold

ipv4 access-list maximum ace threshold

ipv4 access-list maximum acl threshold

ipv6 access-group

ipv6 access-list

ipv6 access-list log-update threshold

ipv6 access-list maximum ace threshold

ipv6 access-list maximum acl threshold

permit (IPv4)

permit (IPv6)

remark (IPv4)

remark (IPv6)

resequence access-list ipv4

resequence access-list ipv6

show access-lists ipv4

show access-lists ipv6


Access List Commands on Cisco IOS XR Software


This chapter describes the Cisco IOS XR software commands used to configure IP Version 4 (IPv4) and IP Version 6 (IPv6) access lists.

An access control list (ACL) consists of one or more access control entries (ACEs) that collectively define the network traffic profile. This profile can then be referenced by Cisco IOS XR software features such as traffic filtering, priority or custom queueing, and dynamic access control. Each ACL includes an action element (permit or deny) and a filter element based on criteria such as source address, destination address, protocol, and protocol-specific parameters.

For detailed information about ACL concepts, configuration tasks, and examples, see the Cisco IOS XR IP Addresses and Services Configuration Guide.

clear access-list ipv4

To clear IPv4 access list counters, use the clear access-list ipv4 command in EXEC mode.

clear access-list ipv4 access-list-name [sequence number | hardware {ingress | egress} {location node-id} | sequence-number]

Syntax Description

access-list-name

Name of a particular IPv4 access list. The name cannot contain a space or quotation mark; it may contain numbers.

sequence number

(Optional) Clears counters for an access list with a specific sequence number. Range is 1 to 2147483646.

hardware

Identifies the access list as an access group for an interface.

ingress

Specifies an inbound direction.

egress

Specifies an outbound direction.

location node-id

(Optional) Clears hardware resource counters from the designated node. The node-id argument is entered in the rack/slot/module notation.

sequence-number

(Optional) Specific sequence number that clears access list counters. Range is 1 to 2147483644.


Defaults

The default clears the specified IPv4 access list.

Command Modes

EXEC

Command History

Release
Modification

Release 2.0

This command was introduced on the Cisco CRS-1.

Release 3.0

No modification.

Release 3.2

This command was supported on the Cisco XR 12000 Series Router. The range for the sequence-number argument was changed from 2147483646 to 2147483644. The command name was changed from clear ipv4 access-list to clear access-list ipv4.


Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.

Use the clear access-list ipv4 command to clear counters for a specified configured access list. Use a sequence number to clear counters for an access list with a specific sequence number.

Use the hardware keyword to clear counters for an access list that was enabled using the ipv4 access-group command.

Use an asterisk (*) in place of the access-list-name argument to clear all access lists.


Note An access list can be shared among multiple interfaces. Clearing hardware counters clears all counters for all interfaces that use the specified access list in a given direction (ingress or egress).


Examples

In the following example, counters for an access list named marketing are cleared:

RP/0/RP0/CPU0:router# show access-lists ipv4 marketing
 
   
ipv4 access-list marketing
  10 permit ip 192.168.34.0 0.0.0.255 any (51 matches)
  20 permit ip 172.16.0.0 0.0.255.255 any (26 matches)
  30 deny tcp host 172.16.0.0 eq bgp host 192.168.202.203 30 (5 matches)
 
   
RP/0/RP0/CPU0:router# clear access-list ipv4 marketing
 
   
RP/0/RP0/CPU0:router# show access-lists ipv4 marketing
 
   
ipv4 access-list marketing
  10 permit ip 192.168.34.0 0.0.0.255 any
  20 permit ip 172.16.0.0 0.0.255.255 any 
  30 deny tcp host 172.16.0.0 eq bgp host 192.168.202.203 30
 
   

In the following example, counters for an access list named acl_hw_1 in the outbound direction are cleared:

RP/0/RP0/CPU0:router# show access-lists ipv4 acl_hw_1 hardware egress location 0/2/cp0
 
   
ipv4 access-list acl_hw_1
  10 permit icmp 192.168.36.0 0.0.0.255 any (251 hw matches)
  20 permit ip 172.16.3.0 0.0.255.255 any (29 hw matches)
  30 deny tcp any any (58 hw matches)
 
   
RP/0/RP0/CPU0:router# clear access-list ipv4 acl_hw_1 hardware egress location 0/2/cp0
 
   
RP/0/RP0/CPU0:router# show access-lists ipv4 acl_hw_1 hardware egress location 0/2/cp0
 
   
ipv4 access-list acl_hw_1
  10 permit icmp 192.168.36.0 0.0.0.255 any
  20 permit ip 172.16.3.0 0.0.255.255 any 
  30 deny tcp any any

Related Commands

Command
Description

ipv4 access-group

Filters incoming or outgoing IPv4 traffic on an interface.

ipv4 access-list

Defines an IPv4 access list and enters IPv4 access list configuration mode.

resequence access-list ipv4

Renumbers an existing statement and increments subsequent statements to allow a new IPv4 access list statements.


clear access-list ipv6

To clear IPv6 access list counters, use the clear access-list ipv6 command in EXEC mode.

clear access-list ipv6 access-list-name [sequence number | hardware {ingress | egress} {location node-id} | sequence-number]

Syntax Description

access-list-name

Name of a particular IPv6 access list. The name cannot contain a space or quotation mark; it may contain numbers.

sequence number

(Optional) Clears counters for an access list with a specific sequence number. Range is 1 to 2147483646.

hardware

Identifies the access list as an access group for an interface.

ingress

Specifies an inbound direction.

egress

Specifies an outbound direction.

location node-id

Clears counters for an access list enabled on a card interface. The node-id argument is entered in the rack/slot/module notation.

sequence-number

(Optional) Specific sequence number that clears access list counters. Range is 1 to 2147483644.


Defaults

The default clears the specified IPv6 access list.

Command Modes

EXEC

Command History

Release
Modification

Release 2.0

This command was introduced on the Cisco CRS-1.

Release 3.0

No modification.

Release 3.2

This command was supported on the Cisco XR 12000 Series Router. The range for the sequence-number argument was changed from 2147483646 to 2147483644. The command name was changed from clear ipv6 access-list to clear access-list ipv6.


Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.

The clear access-list ipv6 command is similar to the clear access-list ipv4 command, except that it is IPv6 specific.

Use the clear access-list ipv6 command to clear counters for a specified configured access list. Use a sequence number to clear counters for an access list with a specific sequence number

Use the hardware keyword to clear counters for an access list that was enabled using the ipv6 access-group command.

Use an asterisk (*) in place of the access-list-name argument to clear all access lists.


Note An access list can be shared among multiple interfaces. Clearing hardware counters clears all counters for all interfaces that use the specified access list in a given direction (ingress or egress).


Examples

In the following example, counters for an access list named marketing are cleared:

RP/0/RP0/CPU0:router# show access-lists ipv6 marketing
 
   
ipv6 access-list marketing
  10 permit ipv6 3333:1:2:3::/64 any (51 matches)
  20 permit ipv6 4444:1:2:3::/64 any (26 matches)
  30 permit ipv6 5555:1:2:3::/64 any (5 matches)
 
   
RP/0/RP0/CPU0:router# clear access-list ipv6 marketing
 
   
RP/0/RP0/CPU0:router# show access-lists ipv6 marketing
 
   
ipv6 access-list marketing
  10 permit ipv6 3333:1:2:3::/64 any
  20 permit ipv6 4444:1:2:3::/64 any
  30 permit ipv6 5555:1:2:3::/64 any
 
   

In the following example, counters for an access list named acl_hw_1 in the outbound direction are cleared:

RP/0/RP0/CPU0:router# show access-lists ipv6 acl_hw_1 hardware egress location 0/2/cp0
 
   
ipv6 access-list acl_hw_1
  10 permit ipv6 3333:1:2:3::/64 any (251 hw matches)
  20 permit ipv6 4444:1:2:3::/64 any (29 hw matches)
  30 deny tcp any any (58 hw matches)
 
   
RP/0/RP0/CPU0:router# clear access-list ipv6 acl_hw_1 hardware egress location 0/2/cp0
 
   
RP/0/RP0/CPU0:router# show access-lists ipv6 acl_hw_1 hardware egress location 0/2/cp0
 
   
ipv6 access-list acl_hw_1
  10 permit ipv6 3333:1:2:3::/64 any
  20 permit ipv6 4444:1:2:3::/64 any
  30 deny tcp any any

Related Commands

Command
Description

ipv6 access-group

Filters incoming or outgoing IPv6 traffic on an interface.

ipv6 access-list

Defines an IPv6 access list and enters IPv6 access list configuration mode.

show access-lists ipv6

Displays the contents of all current IPv6 access lists.


copy access-list ipv4

To create a copy of an existing IPv4 access list, use the copy access-list ipv4 command in EXEC mode.

copy access-list ipv4 source-acl destination-acl

Syntax Description

source-acl

Name of the access list to be copied.

destination-acl

Name of the destination access list where the contents of the source-acl argument is copied.


Defaults

No default behavior or values.

Command Modes

EXEC

Command History

Release
Modification

Release 2.0

This command was introduced on the Cisco CRS-1.

Release 3.0

No modification.

Release 3.2

This command was supported on the Cisco XR 12000 Series Router. The command name was changed from copy ipv4 access-list to copy access-list ipv4.


Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.

Use the copy access-list ipv4 command to copy a configured access list. Use the source-acl argument to specify the access list to be copied and the destination-acl argument to specify where to copy the contents of the source access list. The destination-acl argument must be a unique name; if the destination-acl argument name exists for an access list or prefix list, the access list is not copied. The copy access-list ipv4 command checks that the source access list exists then checks the existing list names to prevent overwriting existing access lists or prefix lists.

Examples

In the following example, a copy of access list list-1 is created:

RP/0/RP0/CPU0:router# show access-lists ipv4 list-1
 
   
ipv4 access-list list-1
  10 permit tcp any any log
  20 permit ip any any
RP/0/RP0/CPU0:router# copy access-list ipv4 list-1 list-2
RP/0/RP0/CPU0:router# show access-lists ipv4 list-2
 
   
ipv4 access-list list-2
  10 permit tcp any any log
  20 permit ip any any

In the following example, copying the access list list-1 to list-3 is denied because a list-3 access list already exists:

RP/0/RP0/CPU0:router# copy access-list ipv4 list-1 list-3
 
   
list-3 exists in access-list
 
   
RP/0/RP0/CPU0:router# show access-lists ipv4 list-3
 
   
ipv4 access-list list-3
  10 permit ip any any 
  20 deny tcp any any log

Related Commands

Command
Description

ipv4 access-list

Defines an IPv4 access list and enters IPv4 access list configuration mode.

show access-lists ipv4

Displays the contents of all current IPv4 access lists.


copy access-list ipv6

To create a copy of an existing IPv6 access list, use the copy access-list ipv6 command in EXEC mode.

copy access-list ipv6 source-acl destination-acl

Syntax Description

source-acl

Name of the access list to be copied.

destination-acl

Destination access list where the contents of the source-acl argument is copied.


Defaults

No default behavior or value.

Command Modes

EXEC

Command History

Release
Modification

Release 2.0

This command was introduced on the Cisco CRS-1.

Release 3.0

No modification.

Release 3.2

This command was supported on the Cisco XR 12000 Series Router. The command name was changed from copy ipv6 access-list to copy access-list ipv6.


Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.

Use the copy access-list ipv6 command to copy a configured access list. Use the source-acl argument to specify the access list to be copied and the destination-acl argument to specify where to copy the contents of the source access list. The destination-acl argument must be a unique name; if the destination-acl argument name exists for an access list or prefix list, the access list is not copied. The copy access-list ipv6 command checks that the source access list exists then checks the existing list names to prevent overwriting existing access lists or prefix lists.

Examples

In the following example, a copy of access list list-1 is created:

RP/0/RP0/CPU0:router# show access-lists ipv6 list-1
 
   
ipv6 access-list list-1
  10 permit tcp any any log
  20 permit ipv6 any any
 
   
RP/0/RP0/CPU0:router# copy access-list ipv6 list-1 list-2
RP/0/RP0/CPU0:router# show access-lists ipv6 list-2
 
   
ipv6 access-list list-2
  10 permit tcp any any log
  20 permit ipv6 any any

In the following example, copying access list list-1 to list-3 is denied because a list-3 access list already exists:

RP/0/RP0/CPU0:router# copy access-list ipv6 list-1 list-3
 
   
list-3 exists in access-list
 
   
RP/0/RP0/CPU0:router# show access-lists ipv6 list-3
 
   
ipv6 access-list list-3
  10 permit ipv6 any any 
  20 deny tcp any any log

Related Commands

Command
Description

ipv6 access-list

Defines an IPv6 access list and enters IPv6 access list configuration mode.

show access-lists ipv6

Displays the contents of all current IPv6 access lists.


deny (IPv4)

To set conditions for an IPv4 access list, use the deny command in access list configuration mode. There are two versions of the deny command: deny (source), and deny (protocol). To remove a condition from an access list, use the no form of this command.

[sequence-number] deny source [source-wildcard] [log | log-input]

[sequence-number] deny protocol source source-wildcard destination destination-wildcard [precedence precedence] [dscp dscp] [fragments] [log | log-input]

no sequence-number

Internet Control Message Protocol (ICMP)

[sequence-number] deny icmp source source-wildcard destination destination-wildcard [icmp-type] [icmp-code] [precedence precedence] [dscp dscp] [fragments] [log | log-input]

Internet Group Management Protocol (IGMP)

[sequence-number] deny igmp source source-wildcard destination destination-wildcard [igmp-type] [precedence precedence] [dscp value] [fragments] [log | log-input]

Stream Control Transmission Protocol (SCTP)

[sequence-number] deny sctp source source-wildcard [operator {port | protocol-port}] destination destination-wildcard [operator {port | protocol-port}] [established] [ack] [rst] [syn] [fin] [psh] [urg] [precedence precedence] [dscp dscp] [fragments] [log | log-input]

Transmission Control Protocol (TCP)

[sequence-number] deny tcp source source-wildcard [operator {port | protocol-port}] destination destination-wildcard [operator {port | protocol-port}] [established] [ack] [rst] [syn] [fin] [psh] [urg] [precedence precedence] [dscp dscp] [fragments] [log | log-input]

User Datagram Protocol (UDP)

[sequence-number] deny udp source source-wildcard [operator {port | protocol-port}] destination destination-wildcard [operator {port | protocol-port}] [precedence precedence] [dscp dscp] [fragments] [log | log-input]

Syntax Description

sequence-number

(Optional) Number of the deny statement in the access list. This number determines the order of the statements in the access list. The number can be from 1 to 2147483646. (By default, the first statement is number 10, and the subsequent statements are incremented by 10.) Use the resequence access-list command to change the number of the first statement and increment subsequent statements of a configured access list.

source

Number of the network or host from which the packet is being sent. There are three alternative ways to specify the source:

Use a 32-bit quantity in four-part dotted-decimal format.

Use the any keyword as an abbreviation for a source and source-wildcard of 0.0.0.0 255.255.255.255.

Use the host source combination as an abbreviation for a source and source-wildcard of source 0.0.0.0.

source-wildcard

Wildcard bits to be applied to the source. There are three alternative ways to specify the source wildcard:

Use a 32-bit quantity in four-part dotted-decimal format. Place ones in the bit positions you want to ignore.

Use the any keyword as an abbreviation for a source and source-wildcard of 0.0.0.0 255.255.255.255.

Use the host source combination as an abbreviation for a source and source-wildcard of source 0.0.0.0.

protocol

Name or number of an IP protocol. It can be one of the keywords ahp, esp, eigrp, gre, icmp, igmp, igrp, ip, ipinip, nos, ospf, pim, pcp, sctp, tcp, or udp, or an integer from 0 to 255 representing an IP protocol number. To match any Internet protocol (including ICMP, TCP, and UDP), use the ip keyword. ICMP, SCTP, and TCP allow further qualifiers, which are described later in this table.

destination

Number of the network or host to which the packet is being sent. There are three alternative ways to specify the destination:

Use a 32-bit quantity in four-part dotted-decimal format.

Use the any keyword as an abbreviation for the destination and destination-wildcard of 0.0.0.0 255.255.255.255.

Use the host destination combination as an abbreviation for a destination and destination-wildcard of destination 0.0.0.0.

destination-wildcard

Wildcard bits to be applied to the destination. There are three alternative ways to specify the destination wildcard:

Use a 32-bit quantity in four-part dotted-decimal format. Place ones in the bit positions you want to ignore.

Use the any keyword as an abbreviation for a destination and destination-wildcard of 0.0.0.0 255.255.255.255.

Use the host destination combination as an abbreviation for a destination and destination-wildcard of destination 0.0.0.0.

precedence precedence

(Optional) Packets can be filtered by precedence level (as specified by a number from 0 to 7) or by the following names:

match-Match packets with routine precedence (0)

priority-Match packets with priority precedence (1)

immediate-Match packets with immediate precedence (2)

flash-Match packets with flash precedence (3)

flash-override-Match packets with flash override precedence (4)

critical-Match packets with critical precedence (5)

internet-Match packets with internetwork control precedence (6)

network-Match packets with network control precedence (7)

dscp dscp

(Optional) Differentiated services code point (DSCP) provides quality of service control. The values for dscp are as follows:

0—63-Differentiated services codepoint value

af11-Match packets with AF11 dscp (001010)

af12-Match packets with AF12 dscp (001100)

af13-Match packets with AF13 dscp (001110)

af21-Match packets with AF21 dscp (010010)

af22-Match packets with AF22 dscp (010100)

af23-Match packets with AF23 dscp (010110)

af31-Match packets with AF31 dscp (011010)

af32-Match packets with AF32 dscp (011100)

af33-Match packets with AF33 dscp (011110)

af41-Match packets with AF41 dscp (100010)

af42—Match packets with AF42 dscp (100100)

af43-Match packets with AF43 dscp (100110)

cs1-Match packets with CS1(precedence 1) dscp (001000)

cs2-Match packets with CS2(precedence 2) dscp (010000)

cs3-Match packets with CS3(precedence 3) dscp (011000)

cs4-Match packets with CS4(precedence 4) dscp (100000)

cs5-Match packets with CS5(precedence 5) dscp (101000)

cs6-Match packets with CS6(precedence 6) dscp (110000)

cs7-Match packets with CS7(precedence 7) dscp (111000)

default-Default DSCP (000000)

ef-Match packets with EF dscp (101110)

fragments

(Optional) Causes the software to examine fragments of IPv4 packets when applying this access list entry. When this keyword is specified, fragments are subject to the access list entry.

log

(Optional) Causes an informational logging message about the packet that matches the entry to be sent to the console. (The level of messages logged to the console is controlled by the logging console command.)

The message includes the access list number, whether the packet was permitted or denied; the protocol, whether it was TCP, UDP, ICMP, or a number; and, if appropriate, the source and destination addresses and source and destination port numbers. The message is generated for the first packet that matches a flow, and then at 5-minute intervals, including the number of packets permitted or denied in the prior 5-minute interval.

log-input

(Optional) Provides the same function as the log keyword, except that the logging message also includes the input interface.

icmp-type

(Optional) ICMP message type for filtering ICMP packets. Range is from 0 to 255.

icmp-code

(Optional) ICMP message code for filtering ICMP packets. Range is from 0 to 255.

igmp-type

(Optional) IGMP message type (0 to 15) or message name for filtering IGMP packets, as follows:

dvmrp

host-query

host-report

mtrace

mtrace-response

pim

precedence

trace

v2-leave

v2-report

v3-report

operator

(Optional) Operator is used to compare source or destination ports. Possible operands are lt (less than), gt (greater than), eq (equal), neq (not equal), and range (inclusive range).

If the operator is positioned after the source and source-wildcard values, it must match the source port.

If the operator is positioned after the destination and destination-wildcard values, it must match the destination port.

The range operator requires two port numbers. All other operators require one port number.

port

Decimal number of a TCP or UDP port. A port number is a number from 0 to 65535.

TCP ports can be used only when filtering TCP. UDP ports can be used only when filtering UDP.

protocol-port

Name of a TCP or UDP port. TCP and UDP port names are listed in the "Usage Guidelines" section.

TCP port names can be used only when filtering TCP. UDP port names can be used only when filtering UDP.

established

(Optional) For the TCP protocol only: Indicates an established connection. A match occurs if the TCP datagram has the Acknowledgment (ACK) or Reset (RST) bit set. The nonmatching case is that of the initial TCP datagram to form a connection.

ack

(Optional) For the TCP protocol only: sets the ACK bit.

rst

(Optional) For the TCP protocol only: sets the RST bit.

syn

(Optional) For the TCP protocol only: sets the Synchronize bit.

fin

(Optional) For the TCP protocol only: sets the Fin bit; no more data from sender.

psh

(Optional) For the TCP protocol only: sets the Push bit.

urg

(Optional) Supported only on the Cisco XR 12000 Series Router. For the TCP protocol only: sets the Urgent bit.


Defaults

There is no specific condition under which a packet is denied passing the IPv4 access list.

Command Modes

IPv4 access list configuration

Command History

Release
Modification

Release 2.0

This command was introduced on the Cisco CRS-1.

Release 3.0

No modification.

Release 3.2

This command was supported on the Cisco XR 12000 Series Router.


Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.

Use the deny command following the ipv4 access-list command to specify conditions under which a packet cannot pass the access list.

By default, the first statement in an access list is number 10, and the subsequent statements are incremented by 10.

You can add permit, deny, or remark statements to an existing access list without retyping the entire list. To add a new statement anywhere other than at the end of the list, create a new statement with an appropriate entry number that falls between two existing entry numbers to indicate where it belongs.

If you want to add a statement between two consecutively numbered statements (for example, between lines 10 and 11), first use the resequence access-list command to renumber the first statement and increment the entry number of each subsequent statement. The increment argument causes new, unused line numbers between statements. Then add a new statement with the entry-number argument, specifying where it belongs in the access list.

The following is a list of precedence names:

critical

flash

flash-override

immediate

internet

network

priority

routine

The following is a list of ICMP message type names:

administratively-prohibited

alternate-address

conversion-error

dod-host-prohibited

dod-net-prohibited

echo

echo-reply

general-parameter-problem

host-isolated

host-precedence-unreachable

host-redirect

host-tos-redirect

host-tos-unreachable

host-unknown

host-unreachable

information-reply

information-request

mask-reply

mask-request

mobile-redirect

net-redirect

net-tos-redirect

net-tos-unreachable

net-unreachable

network-unknown

no-room-for-option

option-missing

packet-too-big

parameter-problem

port-unreachable

precedence-unreachable

protocol-unreachable

reassembly-timeout

redirect

router-advertisement

router-solicitation

source-quench

source-route-failed

time-exceeded

timestamp-reply

timestamp-request

traceroute

ttl-exceeded

unreachable

The following is a list of TCP port names that can be used instead of port numbers. Refer to the current Assigned Numbers RFC to find a reference to these protocols. You can find port numbers corresponding to these protocols by typing a ? in the place of a port number.

bgp

chargen

cmd

daytime

discard

domain

echo

exec

finger

ftp

ftp-data

gopher

hostname

ident

irc

klogin

kshell

login

lpd

nntp

pim-auto-rp

pop2

pop3

smtp

sunrpc

tacacs

talk

telnet

time

uucp

whois

www

The following UDP port names can be used instead of port numbers. Refer to the current Assigned Numbers RFC to find a reference to these protocols. You can find port numbers corresponding to these protocols by typing a ? in the place of a port number.

biff

bootpc

bootps

discard

dnsix

domain

echo

isakmp

mobile-ip

nameserver

netbios-dgm

netbios-ns

netbios-ss

ntp

pim-auto-rp

rip

snmp

snmptrap

sunrpc

syslog

tacacs

talk

tftp

time

who

xdmcp

Examples

The following example shows how to set a deny condition for an access list named Internetfilter:

RP/0/RP0/CPU0:router(config)# ipv4 access-list Internetfilter
RP/0/RP0/CPU0:router(config-ipv4-acl)# 10 deny 192.168.34.0 0.0.0.255
RP/0/RP0/CPU0:router(config-ipv4-acl)# 20 deny 172.16.0.0 0.0.255.255
RP/0/RP0/CPU0:router(config-ipv4-acl)# 25 deny tcp host 172.16.0.0 eq bgp host 
192.168.202.203 range 1300 1400
RP/0/RP0/CPU0:router(config-ipv4-acl)# permit 10.0.0.0 0.255.255.255

Related Commands

Command
Description

ipv4 access-group

Filters incoming or outgoing IPv4 traffic on an interface.

ipv4 access-list

Defines an IPv4 access list and enters IPv4 access list configuration mode.

permit (IPv4)

Sets the permit conditions for an IPv4 access list

remark (IPv4)

Inserts a helpful remark about an IPv4 access list entry.

resequence access-list ipv4

Changes the starting entry number of the first statement in an existing IPv4 access list, and the number by which subsequent statements are incremented.

show access-lists ipv4

Displays the contents of all current IPv4 access lists.


deny (IPv6)

To set deny conditions for an IPv6 access list, use the deny command in IPv6 access list configuration mode. To remove the deny conditions, use the no form of this command.

[sequence-number] deny protocol {source-ipv6-prefix/prefix-length | any | host source-ipv6-address} [operator {port | protocol-port}] {destination-ipv6-prefix/prefix-length | any | host destination-ipv6-address} [operator {port | protocol-port}] [dscp value] [routing] [authen] [destopts] [fragments] [log] [log-input]

no sequence-number

Internet Control Message Protocol (ICMP)

[sequence-number] deny icmp {source-ipv6-prefix/prefix-length | any | host source-ipv6-address} {destination-ipv6-prefix/prefix-length | any | host destination-ipv6-address} [icmp-type] [icmp-code] [dscp value] [routing] [authen] [destopts] [fragments] [log] [log-input]

Transmission Control Protocol (TCP)

[sequence-number] deny tcp {source-ipv6-prefix/prefix-length | any | host source-ipv6-address} [operator {port | protocol-port}] {destination-ipv6-prefix/prefix-length | any | host destination-ipv6-address} [operator {port | protocol-port}] [dscp value] [routing] [authen] [destopts] [fragments] [established] [ack] [fin] [psh] [urg] [rst] [syn] [log] [log-input]

User Datagram Protocol (UDP)

[sequence-number] deny udp {source-ipv6-prefix/prefix-length | any | host source-ipv6-address} [operator {port | protocol-port}] {destination-ipv6-prefix/prefix-length | any | host destination-ipv6-address} [operator {port | protocol-port}] [dscp value] [routing] [authen] [destopts] [fragments] [log] [log-input]

Syntax Description

sequence-number

(Optional) Number of the deny statement in the access list. This number determines the order of the statements in the access list. Range is 1 to 2147483646. (By default, the first statement is number 10, and the subsequent statements are incremented by 10.) Use the resequence access-list command to change the number of the first statement and increment subsequent statements of a configured access list.

protocol

Name or number of an Internet protocol. It can be one of the keywords ahp, esp, icmp, ipv6, pcp, sctp, tcp, or udp, or an integer in the range from 0 to 255 representing an IPv6 protocol number.

source-ipv6-prefix/prefix-length

The source IPv6 network or class of networks about which to set deny conditions.

This argument must be in the form documented in RFC 2373 where the address is specified in hexadecimal using 16-bit values between colons.

any

An abbreviation for the IPv6 prefix ::/0.

host source-ipv6-address

Source IPv6 host address about which to set deny conditions.

This source-ipv6-address argument must be in the form documented in RFC 2373 where the address is specified in hexadecimal using 16-bit values between colons.

operator {port | protocol-port}

(Optional) Operand that compares the source or destination ports of the specified protocol. Operands are lt (less than), gt (greater than), eq (equal), neq (not equal), and range (inclusive range).

If the operator is positioned after the source-ipv6-prefix/prefix-length argument, it must match the source port.

If the operator is positioned after the destination-ipv6-prefix/prefix-length argument, it must match the destination port.

The range operator requires two port numbers. All other operators require one port number.

The port argument is the decimal number of a TCP or UDP port. Range is 0 to 65535. The protocol-port argument is the name of a TCP or UDP port. TCP port names can be used only when filtering TCP. UDP port names can be used only when filtering UDP.

destination-ipv6-prefix/
prefix-length

Destination IPv6 network or class of networks about which to set deny conditions.

This argument must be in the form documented in RFC 2373 where the address is specified in hexadecimal using 16-bit values between colons.

host destination-ipv6-address

Destination IPv6 host address about which to set deny conditions.

This destination-ipv6-address argument must be in the form documented in RFC 2373 where the address is specified in hexadecimal using 16-bit values between colons.

dscp value

(Optional) Matches a differentiated services code point DSCP value against the traffic class value in the Traffic Class field of each IPv6 packet header. Range is 0 to 63.

routing

(Optional) Matches source-routed packets against the routing extension header within each IPv6 packet header.

authen

(Optional) Matches if the IPv6 authentication header is present.

destopts

(Optional) Matches if the IPv6 destination options header is present.

fragments

(Optional) Matches non-initial fragmented packets where the fragment extension header contains a nonzero fragment offset. The fragments keyword is an option only if the operator [port-number] arguments are not specified.

log

(Optional) Causes an informational logging message about the packet that matches the entry to be sent to the console. (The level of messages logged to the console is controlled by the logging console command.)

The message includes the access list name and sequence number, whether the packet was denied; the protocol, whether it was TCP, UDP, ICMP, or a number; and, if appropriate, the source and destination addresses and source and destination port numbers. The message is generated for the first packet that matches, and then at 5-minute intervals, including the number of packets denied in the prior 5-minute interval.

log-input

(Optional) Provides the same function as the log keyword, except that the logging message also includes the input interface.

icmp-type

(Optional) ICMP message type for filtering ICMP packets. ICMP packets can be filtered by ICMP message type. Range is 0 to 255.

icmp-code

(Optional) ICMP message code for filtering ICMP packets. ICMP packets that are filtered by ICMP message type can also be filtered by the ICMP message code. Range is 0 to 255.

established

(Optional) For the TCP protocol only: Indicates an established connection. A match occurs if the TCP datagram has the Acknowledgement (ACK) or Reset (RST) bits set. The nonmatching case is that of the initial TCP datagram to form a connection.

ack

(Optional) For the TCP protocol only: sets ACK bit.

fin

(Optional) For the TCP protocol only: sets Fin bit; no more data from sender.

psh

(Optional) For the TCP protocol only: sets Push bit.

urg

(Optional, only supported on the Cisco XR 12000 Series Router) For the TCP protocol only: sets the Urgent bit.

rst

(Optional) For the TCP protocol only: sets RST bit.

syn

(Optional) For the TCP protocol only: sets Synchronize bit.


Defaults

No IPv6 access list is defined.

Command Modes

IPv6 access list configuration

Command History

Release
Modification

Release 2.0

This command was introduced on the Cisco CRS-1.

Release 3.0

No modification.

Release 3.2

This command was supported on the Cisco XR 12000 Series Router.


Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.

The deny (IPv6) command is similar to the deny (IPv4) command, except that it is IPv6-specific.

Use the deny (IPv6) command following the ipv6 access-list command to define the conditions under which a packet passes the access list.

Specifying ipv6 for the protocol argument matches against the IPv6 header of the packet.

By default, the first statement in an access list is number 10, and the subsequent statements are numbered in increments of 10.

You can add permit, deny, or remark statements to an existing access list without retyping the entire list. To add a new statement anywhere other than at the end of the list, create a new statement with an appropriate entry number that falls between two existing entry numbers to indicate where it belongs.

Both the source-ipv6-prefix/prefix-length and destination-ipv6-prefix/prefix-length arguments are used for traffic filtering (the source prefix filters traffic based upon the traffic source; the destination prefix filters traffic based upon the traffic destination).


Note IPv6 prefix lists, not access lists, should be used for filtering routing protocol prefixes.


The fragments keyword is an option only if the operator {port | protocol-port} arguments are not specified.

Examples

The following example shows how to configure the IPv6 access list named toCISCO and applies the access list to outbound traffic on Packet-over-SONET (PoS) interface 0/2/0/2. Specifically, the first deny entry in the list keeps all packets that have a destination TCP port number greater than 5000 from exiting out of PoS interface 0/2/0/2. The second deny entry in the list keeps all packets that have a source UDPo port number less than 5000 from exiting out of PoS interface 0/2/0/2. The second deny entry also logs all matches to the console. The first permit entry in the list permits all ICMP packets to exit out of PoS interface 0/2/0/2. The second permit entry in the list permits all other traffic to exit out of PoS interface 0/2/0/2. The second permit entry is necessary because an implicit deny all condition is at the end of each IPv6 access list.

RP/0/RP0/CPU0:router(config)# ipv6 access-list toCISCO
RP/0/RP0/CPU0:router(config-ipv6-acl)# deny tcp any any gt 5000
RP/0/RP0/CPU0:router(config-ipv6-acl)# deny ipv6 any lt 5000 any log
RP/0/RP0/CPU0:router(config-ipv6-acl)# permit icmp any any
RP/0/RP0/CPU0:router(config-ipv6-acl)# permit any any
RP/0/RP0/CPU0:router(config)# interface POS 0/2/0/2
RP/0/RP0/CPU0:router(config-if)# ipv6 access-group tOCISCO out

Related Commands

Command
Description

ipv6 access-group

Filters incoming or outgoing IPv6 traffic on an interface.

ipv6 access-list

Defines an IPv6 access list and enters IPv6 access list configuration mode.

permit (IPv6)

Sets permit conditions for an IPv6 access list.

remark (IPv6)

Inserts a helpful remark about an IPv6 access list entry.

resequence access-list ipv6

Changes the starting entry number of the first statement in an existing IPv6 access list, and the number by which subsequent statements are incremented.

show access-lists ipv6

Displays the contents of all current IPv6 access lists.


ipv4 access-group

To control access to an interface, use the ipv4 access-group command in interface configuration mode. To remove the specified access group, use the no form of this command.

ipv4 access-group access-list-name {ingress | egress} [hw-count]

no ipv4 access-group access-list-name {ingress | egress} [hw-count]

Syntax Description

access-list-name

Name of an IPv4 access list as specified by an ipv4 access-list command.

ingress

Filters on inbound packets.

egress

Filters on outbound packets.

hw-count

(Optional) Access group's hardware counters.


Defaults

The interface does not have an IPv4 access list applied to it.

Command Modes

Interface configuration

Command History

Release
Modification

Release 2.0

This command was introduced on the Cisco CRS-1.

Release 3.0

No modification.

Release 3.2

This command was supported on the Cisco XR 12000 Series Router. The keywords {in | out} were changed to {ingress | egress}.


Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.

Use the ipv4 access-group command to control access to an interface. To remove the specified access group, use the no form of the command. Use the access-list-name argument to specify a particular IPv4 access list. Use the ingress keyword to filter on inbound packets or the egress keyword to filter on outbound packets. Use the hw-count argument to enable hardware counters for the access group.

Permitted packets are counted only when hardware counters are enabled using the hw-count argument. Denied packets are counted whether hardware counters are enabled or not.


Note For packet filtering applications using the ipv4 access-group command, packet counters are maintained in hardware for each direction. If an access group is used on multiple interfaces in the same direction, then packets are counted for each interface that has the hw-count argument enabled.


If the access list permits the addresses, the software continues to process the packet. If the access list denies the address, the software discards the packet and returns an Internet Control Message Protocol (ICMP) host unreachable message.

If the specified access list does not exist, all packets are passed.

Examples

The following example shows how to apply filters on packets inbound and outbound from Packet-over-SONET (PoS) interface 0/2/0/2:

RP/0/RP0/CPU0:router(config)# interface POS 0/2/0/2
RP/0/RP0/CPU0:router(config-if)# ipv4 access-group p-ingress-filter in
RP/0/RP0/CPU0:router(config-if)# ipv4 access-group p-egress-filter out

Related Commands

Command
Description

clear access-list ipv4

Resets the IPv4 access list match counters.

deny (IPv4)

Sets the deny conditions for an IPv4 access list.

ipv4 access-list

Defines an IPv4 access list and enters IPv4 access list configuration mode.

permit (IPv4)

Sets the permit conditions for an IPv4 access list

show access-lists ipv4

Displays the contents of all current IPv4 access lists.

show ipv4 interface

Displays the usability status of interfaces configured for IPv4.


ipv4 access-list

To define an IPv4 access list by name, use the ipv4 access-list command in global configuration mode. To remove all entries in an IPv4 access list, use the no form of this command.

ipv4 access-list name

no ipv4 access-list name

Syntax Description

name

Name of the access list. Names cannot contain a space or quotation marks.


Defaults

No IPv4 access list is defined.

Command Modes

Global configuration

Command History

Release
Modification

Release 2.0

This command was introduced on the Cisco CRS-1.

Release 3.0

No modification.

Release 3.2

This command was supported on the Cisco XR 12000 Series Router.


Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.

Use the ipv4 access-list command to configure an IPv4 access list. This command places the router in access list configuration mode, in which the denied or permitted access conditions must be defined with the deny or permit command.

Use the resequence access-list ipv4 command if you want to add a permit, deny, or remark statement between consecutive entries in an existing IPv4 access list. Specify the first entry number (the base) and the increment by which to separate the entry numbers of the statements. The software renumbers the existing statements, thereby making room to add new statements with the unused entry numbers.

Use the ipv4 access-group command to apply the access list to an interface.

Examples

The following example shows how to define a standard access list named Internetfilter:

RP/0/RP0/CPU0:router(config)# ipv4 access-list Internetfilter
RP/0/RP0/CPU0:router(config-if)# 10 permit 192.168.34.0 0.0.0.255
RP/0/RP0/CPU0:router(config-if)# 20 permit 172.16.0.0 0.0.255.255
RP/0/RP0/CPU0:router(config-if)# 30 permit 10.0.0.0 0.255.255.255
RP/0/RP0/CPU0:router(config-if)# 39 remark Block BGP traffic from 172.16 net.
RP/0/RP0/CPU0:router(config-if)# 40 deny tcp host 172.16.0.0 eq bgp host 192.168.202.203 
range 1300 1400

Related Commands

Command
Description

clear access-list ipv4

Resets the IPv4 access list match counters.

deny (IPv4)

Sets the deny conditions for a named IPv4 access list.

ipv4 access-group

Filters incoming or outgoing IPv4 traffic on an interface.

permit (IPv4)

Sets the permit conditions for a named IPv4 access list.

remark (IPv4)

Inserts a helpful remark about an IPv4 access list entry.

resequence access-list ipv4

Changes the starting entry number of the first statement in an existing IPv4 access list, and the number by which subsequent statements are incremented.

show access-lists ipv4

Displays the contents of all current IPv4 access lists.


ipv4 access-list log-update threshold

To specify the number of updates that are logged for IPv4 access lists, use the ipv4 access-list log-update threshold command in global configuration mode. To return the number of logged updates to the default setting, use the no form of this command.

ipv4 access-list log-update threshold update-number

no ipv4 access-list log-update threshold update-number

Syntax Description

update-number

Number of updates that are logged for every IPv4 access list configured on the router. Range is 0 to 2147483647.


Defaults

For IPv4 access lists, 2147483647 updates are logged.

Command Modes

Global configuration

Command History

Release
Modification

Release 2.0

This command was introduced on the Cisco CRS-1.

Release 3.0

No modification.

Release 3.2

This command was supported on the Cisco XR 12000 Series Router.


Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.

IPv4 access list updates are logged at 5-minute intervals, following the first logged update. Configuring a lower number of updates (a number lower than the default) is useful when more frequent update logging is desired.

Examples

The following example shows how to configure a log threshold of ten updates for every IPv4 access list configured on the router:

RP/0/RP0/CPU0:router(config)# ipv4 access-list log-update threshold 10

Related Commands

Command
Description

deny (IPv4)

Sets the deny conditions for an IPv4 access list.

ipv4 access-list

Defines an IPv4 access list and enters IPv4 access list configuration mode.

permit (IPv4)

Sets the permit conditions for an IPv4 access list

show access-lists ipv4

Displays the contents of all current IPv4 access lists.


ipv4 access-list maximum ace threshold

To set the maximum number of access control entries (ACEs) for IPv4 access lists, use the ipv4 access-list maximum ace threshold command in global configuration mode. To reset the ACE limit for IPv4 access lists, use the no form of this command.

ipv4 access-list maximum ace threshold ace-number

no ipv4 access-list maximum ace threshold ace-number

Syntax Description

ace-number

Maximum number of configurable ACEs allowed. Range is 200000 to 350000.


Defaults

200000 ACEs are allowed for IPv4 access lists.

Command Modes

Global configuration

Command History

Release
Modification

Release 2.0

This command was introduced on the Cisco CRS-1.

Release 3.0

No modification.

Release 3.2

This command was supported on the Cisco XR 12000 Series Router.


Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.

Use the ipv4 access-list maximum ace threshold command to set the maximum number of configurable ACEs for IPv4 access lists. Out of resource (OOR) limits the number of ACEs that can be configured in the system. When the maximum number of configurable ACEs is reached, configuration of new ACEs is rejected.

Examples

The following example shows how to set the maximum number of ACEs for IPv4 access lists to 205000:

RP/0/RP0/CPU0:router(config)# ipv4 access-list maximum ace threshold 205000

Related Commands

Command
Description

show access-lists ipv4

Displays the contents of all current IPv4 access lists.


ipv4 access-list maximum acl threshold

To set the maximum number of configurable IPv4 access control lists (ACLs), use the ipv4 access-list maximum acl threshold command in global configuration mode. To reset the IPv4 ACL limit, use the no form of this command.

ipv4 access-list maximum acl threshold acl-number

no ipv4 access-list maximum ace threshold acl-number

Syntax Description

acl-number

Maximum number of configurable ACLs allowed. Range is 5000 to 9000.


Defaults

5000 IPv4 ACLs can be configured.

Command Modes

Global configuration

Command History

Release
Modification

Release 2.0

This command was introduced on the Cisco CRS-1.

Release 3.0

No modification.

Release 3.2

This command was supported on the Cisco XR 12000 Series Router.


Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.

Use the ipv4 access-list maximum acl threshold command to set the maximum number of configurable IPv4 ACLs. Out of resource (OOR) limits the number of ACLs that can be configured in the system. When the maximum number of configurable ACLs is reached, configuration of new ACLs is rejected.

Examples

The following example shows how to set the maximum number of configurable IPv4 ACLs to 6500:

RP/0/RP0/CPU0:router(config)# ipv4 access-list maximum acl threshold 6500

Related Commands

Command
Description

show access-lists ipv4

Displays the contents of all current IPv4 access lists.


ipv6 access-group

To control access to an interface, use the ipv6 access-group command in interface configuration mode. To remove the specified access group, use the no form of this command.

ipv6 access-group access-list-name {in | out}

no ipv6 access-group access-list-name {in | out}

Syntax Description

access-list-name

Name of an IPv6 access list as specified by an ipv6 access-list command.

in

Filters on inbound packets.

out

Filters on outbound packets.


Defaults

The interface does not have an IPv6 access list applied to it.

Command Modes

Interface configuration

Command History

Release
Modification

Release 2.0

This command was introduced on the Cisco CRS-1.

Release 3.0

No modification.

Release 3.2

This command was supported on the Cisco XR 12000 Series Router.


Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.

The ipv6 access-group command is similar to the ipv4 access-group command, except that it is IPv6-specific.

Use the ipv6 access-group command to control access to an interface. To remove the specified access group, use the no form of the command. Use the access-list-name to specify a particular IPv6 access list. Use the in keyword to filter on inbound packets or the out keyword to filter on outbound packets.


Note For packet filtering applications using the ipv6 access-group command, packet counters are maintained in hardware for each direction. If an access group is used on multiple interfaces in the same direction, then packets are counted for each interface.


If the access list permits the addresses, the software continues to process the packet. If the access list denies the address, the software discards the packet and returns a rate-limited Internet Control Message Protocol (ICMP) host unreachable message.

If the specified access list does not exist, all packets are passed.

Examples

The following example shows how to apply filters on packets inbound and outbound from Packet-over-SONET (PoS) interface 0/2/0/2:

RP/0/RP0/CPU0:router(config)# interface POS 0/2/0/2
RP/0/RP0/CPU0:router(config-if)# ipv6 access-group p-in-filter in
RP/0/RP0/CPU0:router(config-if)# ipv6 access-group p-out-filter out

Related Commands

Command
Description

copy access-list ipv6

Copies an existing IPv6 access list.

deny (IPv6)

Sets the deny conditions for an IPv6 access list.

ipv6 access-list

Defines an IPv6 access list and enters IPv6 access list configuration mode.

permit (IPv6)

Sets conditions under which a packet passes a named IPv6 access list.

show access-lists ipv6

Displays the contents of all current IPv6 access lists.

show ipv6 interface

Displays the status and configuration for a specified interface including the inbound and outbound access-lists that are applied to the interface.


ipv6 access-list

To define an IPv6 access list and to place the router in IPv6 access list configuration mode, use the ipv6 access-list command in global configuration mode. To remove the access list, use the no form of this command.

ipv6 access-list name

no ipv6 access-list name

Syntax Description

name

Name of the IPv6 access list. Names cannot contain a space or quotation mark, or begin with a numeric.


Defaults

No IPv6 access list is defined.

Command Modes

Global configuration

Command History

Release
Modification

Release 2.0

This command was introduced on the Cisco CRS-1.

Release 3.0

No modification.

Release 3.2

This command was supported on the Cisco XR 12000 Series Router.


Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.

The ipv6 access-list command is similar to the ipv4 access-list command, except that it is IPv6-specific.

The IPv6 access lists are used for traffic filtering based on source and destination addresses, IPv6 option headers, and optional, upper-layer protocol type information for finer granularity of control. IPv6 access lists are defined by using the ipv6 access-list command in global configuration mode and their permit and deny conditions are set by using the deny and permit commands in IPv6 access list configuration mode. Configuring the ipv6 access-list command places the router in IPv6 access list configuration mode—the router prompt changes to router (config-ipv6-acl)#. From IPv6 access list configuration mode, permit and deny conditions can be set for the defined IPv6 access list.

Refer to the deny (IPv6) and permit (IPv6) commands for more information on filtering IPv6 traffic based on IPv6 option headers and optional, upper-layer protocol type information. See the "Examples" section for an example of a translated IPv6 access control list (ACL) configuration.


Note Every IPv6 access list has an implicit deny ipv6 any any statement as its last match condition. An IPv6 access list must contain at least one entry for the implicit deny ipv6 any any statement to take effect.



Note IPv6 prefix lists, not access lists, should be used for filtering routing protocol prefixes.


Use the ipv6 access-group interface configuration command with the access-list-name argument to apply an IPv6 access list to an IPv6 interface.


Note An IPv6 access list applied to an interface with the ipv6 access-group command filters traffic that is forwarded, not originated, by the router.


Examples

The following example shows how to configure the IPv6 access list named list2 and applies the ACL to outbound traffic on interface Packet-over-SONET (PoS) 0/2/0/2. Specifically, the first ACL entry keeps all packets from the network fec0:0:0:2::/64 (packets that have the site-local prefix fec0:0:0:2 as the first 64 bits of their source IPv6 address) from exiting out of interface PoS 0/2/0/2. The second entry in the ACL permits all other traffic to exit out of interface PoS 0/2/0/2. The second entry is necessary because an implicit deny all condition is at the end of each IPv6 ACL.

RP/0/RP0/CPU0:router(config)# ipv6 access-list list2
 
   
RP/0/RP0/CPU0:router(config-ipv6-acl)# 10 deny fec0:0:0:2::/64 any
RP/0/RP0/CPU0:router(config-ipv6-acl)# 20 permit any any
 
   
RP/0/RP0/CPU0:router# show ipv6 access-lists list2
 
   
ipv6 access-list list2
  10 deny ipv6 fec0:0:0:2::/64 any
  20 permit ipv6 any any
 
   
RP/0/RP0/CPU0:router(config)# interface POS 0/2/0/2
 
   
RP/0/RP0/CPU0:router(config-if)# ipv6 access-group list2 out

Note IPv6 is automatically configured as the protocol type in permit any any and deny any any statements that are translated from global configuration mode to IPv6 access list configuration mode.



Note An IPv6 router does not forward to another network an IPv6 packet that has a link-local address as either its source or destination address (and the source interface for the packet is different from the destination interface for the packet).


Related Commands

Command
Description

deny (IPv6)

Sets the deny conditions for an IPv6 access list.

ipv6 access-group

Filters incoming or outgoing IPv6 traffic on an interface.

permit (IPv6)

Sets permit conditions for an IPv6 access list.

remark (IPv6)

Inserts a helpful remark about an IPv6 access list entry.

show access-lists ipv6

Displays the contents of all current IPv6 access lists.


ipv6 access-list log-update threshold

To specify the number of updates that are logged for IPv6 access lists (ACLs), use the ipv6 access-list log-update threshold command in global configuration mode. To return the number of logged updates to the default setting, use the no form of this command.

ipv6 access-list log-update threshold update-number

no ipv6 access-list log-update threshold update-number

Syntax Description

update-number

Number of updates that are logged for every IPv6 access list configured on the router. Range is 0 to 2147483647.


Defaults

For IPv6 access lists, 2147483647 updates are logged.

Command Modes

Global configuration

Command History

Release
Modification

Release 2.0

This command was introduced on the Cisco CRS-1.

Release 3.0

No modification.

Release 3.2

This command was supported on the Cisco XR 12000 Series Router.


Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.

The ipv6 access-list log-update threshold command is similar to the ipv4 access-list log-update threshold command, except that it is IPv6-specific.

IPv6 access list updates are logged at 5-minute intervals, following the first logged update. Configuring a lower number of updates (a number lower than the default) is useful when more frequent update logging is desired.

Examples

The following example shows how to configure a log threshold of ten updates for every IPv6 access list configured on the router:

RP/0/RP0/CPU0:router(config)# ipv6 access-list log-update threshold 10

Related Commands

Command
Description

show access-lists ipv6

Displays the contents of all current IPv6 access lists.


ipv6 access-list maximum ace threshold

To set the maximum number of access control entries (ACEs) for IPv6 access lists, use the ipv6 access-list maximum ace threshold command in global configuration mode. To reset the ACE limit for IPv6 access lists, use the no form of this command.

ipv6 access-list maximum ace threshold ace-number

no ipv6 access-list maximum ace threshold ace-number

Syntax Description

ace-number

Maximum number of configurable ACEs allowed. Range is 50000 to 100000.


Defaults

50000 ACEs are allowed for IPv4 access lists.

Command Modes

Global configuration

Command History

Release
Modification

Release 2.0

This command was introduced on the Cisco CRS-1.

Release 3.0

No modification.

Release 3.2

This command was supported on the Cisco XR 12000 Series Router.


Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.

Use the ipv6 access-list maximum ace threshold command to set the maximum number of configurable ACEs for IPv6 access lists. Out of resource (OOR) limits the number of ACEs that can be configured in the system. When the maximum number of configurable ACEs is reached, configuration of new ACEs is rejected.

Examples

The following example shows how to set the maximum number of ACEs for IPv6 access lists to 75000:

RP/0/RP0/CPU0:router(config)# ipv6 access-list maximum ace threshold 75000

Related Commands

Command
Description

show access-lists ipv6

Displays the contents of all current IPv6 access lists.


ipv6 access-list maximum acl threshold

To set the maximum number of configurable IPv4 access control lists (ACLs), use the ipv6 access-list maximum acl threshold command in global configuration mode. To reset the IPv6 ACL limit, use the no form of this command.

ipv6 access-list maximum acl threshold acl-number

no ipv6 access-list maximum ace threshold acl-number

Syntax Description

acl-number

Maximum number of configurable ACLs allowed. Range is 1000 to 2000.


Defaults

1000 IPv6 ACLs can be configured.

Command Modes

Global configuration

Command History

Release
Modification

Release 2.0

This command was introduced on the Cisco CRS-1.

Release 3.0

No modification.

Release 3.2

This command was supported on the Cisco XR 12000 Series Router.


Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.

Use the ipv6 access-list maximum acl threshold command to set the maximum number of configurable IPv6 ACLs. Out of resource (OOR) limits the number of ACLs that can be configured in the system. When the limit is reached, configuration of new ACLs is rejected.

Examples

The following example shows how to set the maximum number of configurable IPv6 ACLs to 1500:

RP/0/RP0/CPU0:router(config)# ipv6 access-list maximum acl threshold 1500

Related Commands

Command
Description

show access-lists ipv6

Displays the contents of all current IPv6 access lists.


permit (IPv4)

To set conditions for an IPv4 access list, use the permit command in access list configuration mode. There are two versions of the permit command: permit (source), and permit (protocol). To remove a condition from an access list, use the no form of this command.

[sequence-number] permit source [source-wildcard] [log | log-input]

[sequence-number] permit protocol source source-wildcard destination destination-wildcard [precedence precedence] [dscp dscp] [fragments] [log | log-input]

no sequence-number

Internet Control Message Protocol (ICMP)

[sequence-number] permit icmp source source-wildcard destination destination-wildcard [icmp-type] [icmp-code] [precedence precedence] [dscp dscp] [fragments] [log | log-input]

Internet Group Management Protocol (IGMP)

[sequence-number] permit igmp source source-wildcard destination destination-wildcard [igmp-type] [precedence precedence] [dscp value] [fragments] [log | log-input]

Stream Control Transmission Protocol (SCTP)

[sequence-number] permit sctp source source-wildcard [operator {port | protocol-port}] destination destination-wildcard [operator {port | protocol-port}] [established] [ack] [rst] [syn] [fin] [psh] [urg] [precedence precedence] [dscp dscp] [fragments] [log | log-input]

Transmission Control Protocol (TCP)

[sequence-number] permit tcp source source-wildcard [operator {port | protocol-port}] destination destination-wildcard [operator {port | protocol-port}] [established] [ack] [rst] [syn] [fin] [psh] [urg] [precedence precedence] [dscp dscp] [fragments] [log | log-input]

User Datagram Protocol (UDP)

[sequence-number] permit udp source source-wildcard [operator {port | protocol-port}] destination destination-wildcard [operator {port | protocol-port}] [precedence precedence] [dscp dscp] [fragments] [log | log-input]

Syntax Description

sequence-number

(Optional) Number of the permit statement in the access list. This number determines the order of the statements in the access list. Range is 1 to 2147483646. (By default, the first statement is number 10, and the subsequent statements are incremented by 10.) Use the resequence access-list command to change the number of the first statement and increment subsequent statements of a configured access list.

source

Number of the network or host from which the packet is being sent. There are three alternative ways to specify the source:

Use a 32-bit quantity in four-part dotted-decimal format.

Use the any keyword as an abbreviation for a source and source-wildcard of 0.0.0.0 255.255.255.255.

Use the host source combination as an abbreviation for a source and source-wildcard of source 0.0.0.0.

source-wildcard

Wildcard bits to be applied to the source. There are three alternative ways to specify the source wildcard:

Use a 32-bit quantity in four-part dotted-decimal format. Place ones in the bit positions you want to ignore.

Use the any keyword as an abbreviation for a source and source-wildcard of 0.0.0.0 255.255.255.255.

Use the host source combination as an abbreviation for a source and source-wildcard of source 0.0.0.0.

protocol

Name or number of an IP protocol. It can be one of the keywords ahp, esp, eigrp, gre, icmp, igmp, igrp, ip, ipinip, nos, ospf, pim, pcp, sctp, tcp, or udp, or an integer from 0 to 255 representing an IP protocol number. To match any Internet protocol (including ICMP, TCP, and UDP), use the ip keyword. ICMP, SCTP, and TCP allow further qualifiers, which are described later in this table.

destination

Number of the network or host to which the packet is being sent. There are three alternative ways to specify the destination:

Use a 32-bit quantity in four-part dotted-decimal format.

Use the any keyword as an abbreviation for the destination and destination-wildcard of 0.0.0.0 255.255.255.255.

Use the host destination combination as an abbreviation for a destination and destination-wildcard of destination 0.0.0.0.

destination-wildcard

Wildcard bits to be applied to the destination. There are three alternative ways to specify the destination wildcard:

Use a 32-bit quantity in four-part dotted-decimal format. Place ones in the bit positions you want to ignore.

Use the any keyword as an abbreviation for a destination and destination-wildcard of 0.0.0.0 255.255.255.255.

Use the host destination combination as an abbreviation for a destination and destination-wildcard of destination 0.0.0.0.

precedence precedence

(Optional) Packets can be filtered by precedence level (as specified by a number from 0 to 7) or by the following names:

match-Match packets with routine precedence (0)

priority-Match packets with priority precedence (1)

immediate-Match packets with immediate precedence (2)

flash-Match packets with flash precedence (3)

flash-override-Match packets with flash override precedence (4)

critical-Match packets with critical precedence (5)

internet-Match packets with internetwork control precedence (6)

network-Match packets with network control precedence (7)

dscp dscp

(Optional) Differentiated services code point (DSCP) provides quality of service control. The values for dscp are as follows:

0—63-Differentiated services codepoint value

af11-Match packets with AF11 dscp (001010)

af12-Match packets with AF12 dscp (001100)

af13-Match packets with AF13 dscp (001110)

af21-Match packets with AF21 dscp (010010)

af22-Match packets with AF22 dscp (010100)

af23-Match packets with AF23 dscp (010110)

af31-Match packets with AF31 dscp (011010)

af32-Match packets with AF32 dscp (011100)

af33-Match packets with AF33 dscp (011110)

af41-Match packets with AF41 dscp (100010)

af42—Match packets with AF42 dscp (100100)

af43-Match packets with AF43 dscp (100110)

cs1-Match packets with CS1(precedence 1) dscp (001000)

cs2-Match packets with CS2(precedence 2) dscp (010000)

cs3-Match packets with CS3(precedence 3) dscp (011000)

cs4-Match packets with CS4(precedence 4) dscp (100000)

cs5-Match packets with CS5(precedence 5) dscp (101000)

cs6-Match packets with CS6(precedence 6) dscp (110000)

cs7-Match packets with CS7(precedence 7) dscp (111000)

default-Default DSCP (000000)

ef-Match packets with EF dscp (101110)

fragments

(Optional) Causes the software to examine non-initial fragments of IPv4 packets when applying this access list entry. When this keyword is specified, fragments are subject to the access list entry.

log

(Optional) Causes an informational logging message about the packet that matches the entry to be sent to the console. (The level of messages logged to the console is controlled by the logging console command.)

The message includes the access list number, whether the packet was permitted or denied; the protocol, whether it was TCP, UDP, ICMP, or a number; and, if appropriate, the source and destination addresses and source and destination port numbers. The message is generated for the first packet that matches a flow, and then at 5-minute intervals, including the number of packets permitted or denied in the prior 5-minute interval.

log-input

(Optional) Provides the same function as the log keyword, except that the logging message also includes the input interface.

icmp-type

(Optional) ICMP message type for filtering ICMP packets. Range is from 0 to 255.

icmp-code

(Optional) ICMP message code for filtering ICMP packets. Range is from 0 to 255.

igmp-type

(Optional) IGMP message type (0 to 15) or message name for filtering IGMP packets, as follows:

dvmrp

host-query

host-report

mtrace

mtrace-response

pim

precedence

trace

v2-leave

v2-report

v3-report

operator

(Optional) Operator is used to compare source or destination ports. Possible operands are lt (less than), gt (greater than), eq (equal), neq (not equal), and range (inclusive range).

If the operator is positioned after the source and source-wildcard values, it must match the source port.

If the operator is positioned after the destination and destination-wildcard values, it must match the destination port.

The range operator requires two port numbers. All other operators require one port number.

port

Decimal number a TCP or UDP port. Range is 0 to 65535.

TCP ports can be used only when filtering TCP. UDP ports can be used only when filtering UDP.

protocol-port

Name of a TCP or UDP port. TCP and UDP port names are listed in the "Usage Guidelines" section.

TCP port names can be used only when filtering TCP. UDP port names can be used only when filtering UDP.

established

(Optional) For the TCP protocol only: Indicates an established connection. A match occurs if the TCP datagram has the Acknowledgment (ACK) or Reset (RST) bit set. The nonmatching case is that of the initial TCP datagram to form a connection.

ack

(Optional) For the TCP protocol only: sets the ACK bit.

rst

(Optional) For the TCP protocol only: sets the RST bit.

syn

(Optional) For the TCP protocol only: sets the Synchronize bit.

fin

(Optional) For the TCP protocol only: sets the Fin bit; no more data from sender.

psh

(Optional) For the TCP protocol only: sets the Push function bit.

urg

(Optional, only supported on the Cisco XR 12000 Series Router) For the TCP protocol only: sets the Urgent bit.


Defaults

There is no specific condition under which a packet is denied passing the IPv4 access list.

Command Modes

IPv4 access list configuration

Command History

Release
Modification

Release 2.0

This command was introduced on the Cisco CRS-1.

Release 3.0

No modification.

Release 3.2

This command was supported on the Cisco XR 12000 Series Router.


Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.

Use the permit command following the ipv4 access-list command to specify conditions under which a packet can pass the access list.

By default, the first statement in an access list is number 10, and the subsequent statements are incremented by 10.

You can add permit, deny, or remark statements to an existing access list without retyping the entire list. To add a new statement anywhere other than at the end of the list, create a new statement with an appropriate entry number that falls between two existing entry numbers to indicate where it belongs.

If you want to add a statement between two consecutively numbered statements (for example, between lines 10 and 11), first use the resequence access-list command to renumber the first statement and increment the entry number of each subsequent statement. The increment argument causes new, unused line numbers between statements. Then add a new statement with the entry-number specifying where it belongs in the access list.

The following is a list of precedence names:

critical

flash

flash-override

immediate

internet

network

priority

routine

The following is a list of ICMP message type names:

administratively-prohibited

alternate-address

conversion-error

dod-host-prohibited

dod-net-prohibited

echo

echo-reply

general-parameter-problem

host-isolated

host-precedence-unreachable

host-redirect

host-tos-redirect

host-tos-unreachable

host-unknown

host-unreachable

information-reply

information-request

mask-reply

mask-request

mobile-redirect

net-redirect

net-tos-redirect

net-tos-unreachable

net-unreachable

network-unknown

no-room-for-option

option-missing

packet-too-big

parameter-problem

port-unreachable

precedence-unreachable

protocol-unreachable

reassembly-timeout

redirect

router-advertisement

router-solicitation

source-quench

source-route-failed

time-exceeded

timestamp-reply

timestamp-request

traceroute

ttl-exceeded

unreachable

The following is a list of TCP port names that can be used instead of port numbers. Refer to the current Assigned Numbers RFC to find a reference to these protocols. You can find port numbers corresponding to these protocols by typing a ? in the place of a port number.

bgp

chargen

cmd

daytime

discard

domain

echo

exec

finger

ftp

ftp-data

gopher

hostname

ident

irc

klogin

kshell

login

lpd

nntp

pim-auto-rp

pop2

pop3

smtp

sunrpc

tacacs

talk

telnet

time

uucp

whois

www

The following UDP port names can be used instead of port numbers. Refer to the current Assigned Numbers RFC to find a reference to these protocols. You can find port numbers corresponding to these protocols by typing a ? in the place of a port number.

biff

bootpc

bootps

discard

dnsix

domain

echo

isakmp

mobile-ip

nameserver

netbios-dgm

netbios-ns

netbios-ss

ntp

pim-auto-rp

rip

snmp

snmptrap

sunrpc

syslog

tacacs

talk

tftp

time

who

xdmcp

Examples

The following example shows how to set a permit condition for an access list named Internetfilter:

RP/0/RP0/CPU0:router(config)# ipv4 access-list Internetfilter
RP/0/RP0/CPU0:router(config-ipv4-acl)# 10 permit 192.168.34.0 0.0.0.255
RP/0/RP0/CPU0:router(config-ipv4-acl)# 20 permit 172.16.0.0 0.0.255.255
RP/0/RP0/CPU0:router(config-ipv4-acl)# 25 permit tcp host 172.16.0.0 eq bgp host 
192.168.202.203 range 1300 1400
RP/0/RP0/CPU0:router(config-ipv4-acl)# deny 10.0.0.0 0.255.255.255

Related Commands

Command
Description

deny (IPv4)

Sets the conditions for an IPv4 access list.

ipv4 access-group

Filters incoming or outgoing IPv4 traffic on an interface.

ipv4 access-list

Defines an IPv4 access list and enters IPv4 access list configuration mode.

remark (IPv4)

Inserts a helpful remark about an IPv4 access list entry.

resequence access-list ipv4

Changes the starting entry number of the first statement in an existing IPv4 access list, and the number by which subsequent statements are incremented.

show access-lists ipv4

Displays the contents of all current IPv4 access lists.


permit (IPv6)

To set permit conditions for an IPv6 access list, use the permit command in IPv6 access list configuration mode. To remove the permit conditions, use the no form of this command.

[sequence-number] permit protocol {source-ipv6-prefix/prefix-length | any | host source-ipv6-address} [operator {port | protocol-port}] {destination-ipv6-prefix/prefix-length | any | host destination-ipv6-address} [operator {port | protocol-port}] [dscp value] [routing] [authen] [destopts] [fragments] [log] [log-input]

no sequence-number

Internet Control Message Protocol (ICMP)

[sequence-number] permit icmp {source-ipv6-prefix/prefix-length | any | host source-ipv6-address} {destination-ipv6-prefix/prefix-length | any | host destination-ipv6-address} [icmp-type] [icmp-code] [dscp value] [routing] [authen] [destopts] [fragments] [log] [log-input]

Transmission Control Protocol (TCP)

[sequence-number] permit tcp {source-ipv6-prefix/prefix-length | any | host source-ipv6-address} [operator {port | protocol-port}] {destination-ipv6-prefix/prefix-length | any | host destination-ipv6-address} [operator {port | protocol-port}] [dscp value] [routing] [authen] [destopts] [fragments] [established] [ack] [fin] [psh] [urg] [rst] [syn] [log] [log-input]

User Datagram Protocol (UDP)

[sequence-number] permit udp {source-ipv6-prefix/prefix-length | any | host source-ipv6-address} [operator {port | protocol-port}] {destination-ipv6-prefix/prefix-length | any | host destination-ipv6-address} [operator {port | protocol-port}] [dscp value] [routing] [authen] [destopts] [fragments] [log] [log-input]

Syntax Description

sequence-number

(Optional) Number of the permit statement in the access list. This number determines the order of the statements in the access list. Range is 1 to 2147483646. (By default, the first statement is number 10, and the subsequent statements are incremented by 10.) Use the resequence access-list command to change the number of the first statement and increment subsequent statements of a configured access list.

protocol

Name or number of an Internet protocol. It can be one of the keywords ahp, esp, icmp, ipv6, pcp, sctp, tcp, or udp, or an integer in the range from 0 to 255 representing an IPv6 protocol number.

source-ipv6-prefix/prefix-length

Source IPv6 network or class of networks about which to set permit conditions.

This argument must be in the form documented in RFC 2373 where the address is specified in hexadecimal using 16-bit values between colons.

any

An abbreviation for the IPv6 prefix ::/0.

host source-ipv6-address

Source IPv6 host address about which to set permit conditions.

This source-ipv6-address argument must be in the form documented in RFC 2373 where the address is specified in hexadecimal using 16-bit values between colons.

operator {port | protocol-port}

(Optional) Operand that compares the source or destination ports of the specified protocol. Operands are lt (less than), gt (greater than), eq (equal), neq (not equal), and range (inclusive range).

If the operator is positioned after the source-ipv6-prefix/prefix-length argument, it must match the source port.

If the operator is positioned after the destination-ipv6-prefix/prefix-length argument, it must match the destination port.

The range operator requires two port numbers. All other operators require one port number.

The port argument is the decimal number of a TCP or UDP port. A port number is a number from 0 to 65535. The protocol-port argument is the name of a TCP or UDP port. TCP port names can be used only when filtering TCP. UDP port names can be used only when filtering UDP.

destination-ipv6-prefix/
prefix-length

Destination IPv6 network or class of networks about which to set permit conditions.

This argument must be in the form documented in RFC 2373 where the address is specified in hexadecimal using 16-bit values between colons.

host destination-ipv6-address

Specifies the destination IPv6 host address about which to set permit conditions.

This destination-ipv6-address argument must be in the form documented in RFC 2373 where the address is specified in hexadecimal using 16-bit values between colons.

dscp value

(Optional) Matches a differentiated services code point (DSCP) value against the traffic class value in the Traffic Class field of each IPv6 packet header. Range is 0 to 63.

routing

(Optional) Matches source-routed packets against the routing extension header within each IPv6 packet header.

authen

(Optional) Matches if the IPv6 authentication header is present.

destopts

(Optional) Matches if the IPv6 destination options header is present.

fragments

(Optional) Matches non-initial fragmented packets where the fragment extension header contains a nonzero fragment offset. The fragments keyword is an option only if the operator [port-number] arguments are not specified.

log

(Optional) Causes an informational logging message about the packet that matches the entry to be sent to the console. (The level of messages logged to the console is controlled by the logging console command.)

The message includes the access list name and sequence number, whether the packet was permitted; the protocol, whether it was TCP, UDP, ICMP, or a number; and, if appropriate, the source and destination addresses and source and destination port numbers. The message is generated for the first packet that matches, and then at 5-minute intervals, including the number of packets permitted in the prior 5-minute interval.

log-input

(Optional) Provides the same function as the log keyword, except that the logging message also includes the input interface.

icmp-type

(Optional) ICMP message type for filtering ICMP packets. Range is from 0 to 255.

icmp-code

(Optional) ICMP message code for filtering ICMP packets. Range is from 0 to 255.

established

(Optional) For the TCP protocol only: Indicates an established connection. A match occurs if the TCP datagram has the Acknowledgement (ACK) or Reset (RST) bits set. The nonmatching case is that of the initial TCP datagram to form a connection.

ack

(Optional) For the TCP protocol only: Sets ACK bit.

fin

(Optional) For the TCP protocol only: Sets fin bit; no more data from sender.

psh

(Optional) For the TCP protocol only: Sets push bit.

urg

(Optional, only supported on the Cisco XR 12000 Series Router) For the TCP protocol only: sets the Urgent bit.

rst

(Optional) For the TCP protocol only: Sets RST bit.

syn

(Optional) For the TCP protocol only: Sets synchronize bit.


Defaults

No IPv6 access list is defined.

Command Modes

IPv6 access list configuration

Command History

Release
Modification

Release 2.0

This command was introduced on the Cisco CRS-1.

Release 3.0

No modification.

Release 3.2

This command was supported on the Cisco XR 12000 Series Router.


Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.

The permit (IPv6) command is similar to the permit (IPv4) command, except that it is IPv6-specific.

Use the permit (IPv6) command following the ipv6 access-list command to define the conditions under which a packet passes the access list.

Specifying ipv6 for the protocol argument matches against the IPv6 header of the packet.

By default, the first statement in an access list is number 10, and the subsequent statements are numbered in increments of 10.

You can add permit, deny, or remark statements to an existing access list without retyping the entire list. To add a new statement anywhere other than at the end of the list, create a new statement with an appropriate entry number that falls between two existing entry numbers to indicate where it belongs.

Both the source-ipv6-prefix/prefix-length and destination-ipv6-prefix/prefix-length arguments are used for traffic filtering (the source prefix filters traffic based upon the traffic source; the destination prefix filters traffic based upon the traffic destination).


Note IPv6 prefix lists, not access lists, should be used for filtering routing protocol prefixes.


The fragments keyword is an option only if the operator {port | protocol-port} arguments are not specified.

Examples

The following example shows how to configure the IPv6 access list named toCISCO and applies the access list to outbound traffic on Packet-over-SONET (PoS) interface 0/2/0/2. Specifically, the first deny entry in the list keeps all packets that have a destination TCP port number greater than 5000 from exiting out of PoS interface 0/2/0/2. The second deny entry in the list keeps all packets that have a source UDP port number less than 5000 from exiting out of PoS interface 0/2/0/2. The second deny entry also logs all matches to the console. The first permit entry in the list permits all ICMP packets to exit out of PoS interface 0/2/0/2. The second permit entry in the list permits all other traffic to exit out of PoS interface 0/2/0/2. The second permit entry is necessary because an implicit deny all condition is at the end of each IPv6 access list.

RP/0/RP0/CPU0:router(config)# ipv6 access-list toCISCO
RP/0/RP0/CPU0:router(config-ipv6-acl)# deny tcp any any gt 5000
RP/0/RP0/CPU0:router(config-ipv6-acl)# deny ipv6 any lt 5000 any log
RP/0/RP0/CPU0:router(config-ipv6-acl)# permit icmp any any
RP/0/RP0/CPU0:router(config-ipv6-acl)# permit any any
RP/0/RP0/CPU0:router(config)# interface POS 0/2/0/2
RP/0/RP0/CPU0:router(config-if)# ipv6 access-group tOCISCO out

Related Commands

Command
Description

deny (IPv6)

Sets deny conditions for an IPv6 access list.

ipv6 access-group

Filters incoming or outgoing IPv6 traffic on an interface.

ipv6 access-list

Defines an IPv6 access list and enters IPv6 access list configuration mode.

remark (IPv6)

Inserts a helpful remark about an IPv6 access list entry.

resequence access-list ipv6

Changes the starting entry number of the first statement in an existing IPv6 access list, and the number by which subsequent statements are incremented.

show access-lists ipv6

Displays the contents of all current IPv6 access lists.


remark (IPv4)

To write a helpful comment (remark) for an entry in an IPv4 access list, use the remark command in IPv4 access list configuration mode. To remove the remark, use the no form of this command.

[sequence-number] remark remark

no sequence-number

Syntax Description

sequence-number

(Optional) Number of the remark statement in the access list. This number determines the order of the statements in the access list. Range is 1 to 2147483646. (By default, the first statement is number 10, and the subsequent statements are incremented by 10.)

remark

Comment that describes the entry in the access list, up to 255 characters long.


Defaults

The IPv4 access list entries have no remarks.

Command Modes

IPv4 access list configuration

Command History

Release
Modification

Release 2.0

This command was introduced on the Cisco CRS-1.

Release 3.0

No modification.

Release 3.2

This command was supported on the Cisco XR 12000 Series Router.


Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.

Use the remark command to write a helpful comment for an entry in an IPv4 access list. To remove the remark, use the no form of this command.

The remark can be up to 255 characters; anything longer is truncated.

If you know the sequence number of the remark you want to delete, you can remove it by entering the no sequence-number command.

Use the resequence access-list ipv4 command if you want to add statements to an existing access list and the sequence numbers of consecutive entries do not permit additional statements.

Examples

In the following example, the user1 subnet is not allowed to use outbound Telnet:

RP/0/RP0/CPU0:router(config)# ipv4 access-list telnetting
RP/0/RP0/CPU0:router(config-ipv4-acl)# 10 remark Do not allow user1 to telnet out
RP/0/RP0/CPU0:router(config-ipv4-acl)# 20 deny tcp host 172.16.2.88 255.255.0.0 any eq 
telnet
RP/0/RP0/CPU0:router(config-ipv4-acl)# 30 permit icmp any any
RP/0/RP0/CPU0:router# show ipv4 access-list telnetting
 
   
ipv4 access-list telnetting
  0 remark Do not allow user1 to telnet out
  20 deny tcp 172.16.2.88 255.255.0.0 any eq telnet out
  30 permit icmp any any

Related Commands

Command
Description

deny (IPv4)

Sets the deny conditions for an IPv4 access list.

ipv4 access-list

Defines an IPv4 access list and enters IPv4 access list configuration mode.

permit (IPv4)

Sets the permit conditions for an IPv4 access list

resequence access-list ipv4

Changes the starting entry number of the first statement in an existing IPv4 access list, and the number by which subsequent statements are incremented.

show access-lists ipv4

Displays the contents of all current IPv4 access lists.


remark (IPv6)

To write a helpful comment (remark) for an entry in an IPv6 access list, use the remark command in IPv6 access list configuration mode. To remove the remark, use the no form of this command.

[sequence-number] remark remark

no sequence-number

Syntax Description

sequence-number

(Optional) Number of the remark statement in the access list. This number determines the order of the statements in the access list. Range is 1 to 2147483646. (By default, the first statement is number 10, and the subsequent statements are incremented by 10.)

remark

Comment that describes the entry in the access list, up to 255 characters long.


Defaults

The IPv6 access list entries have no remarks.

Command Modes

IPv6 access list configuration

Command History

Release
Modification

Release 2.0

This command was introduced on the Cisco CRS-1.

Release 3.0

No modification.

Release 3.2

This command was supported on the Cisco XR 12000 Series Router.


Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.

The remark (IPv6) command is similar to the remark (IPv4) command, except that it is IPv6-specific.

Use the remark command to write a helpful comment for an entry in an IPv6 access list. To remove the remark, use the no form of this command.

The remark can be up to 255 characters; anything longer is truncated.

If you know the sequence number of the remark you want to delete, you can remove it by entering the no sequence-number command.

Use the resequence access-list ipv6 command if you want to add statements to an existing access list and the sequence numbers of consecutive entries do not permit additional statements.

Examples

In the following example, a remark is added:

RP/0/RP0/CPU0:router(config)# ipv6 access-list Internetfilter
RP/0/RP0/CPU0:router(config-ipv6-acl)# 10 permit ipv6 3333:1:2:3::/64 any
RP/0/RP0/CPU0:router(config-ipv6-acl)# 20 permit ipv6 4444:1:2:3::/64 any
RP/0/RP0/CPU0:router(config-ipv6-acl)# 30 permit ipv6 5555:1:2:3::/64 any
RP/0/RP0/CPU0:router(config-ipv6-acl)# 39 remark Block BGP traffic from a given host
RP/0/RP0/CPU0:router(config-ipv6-acl)# 40 deny tcp host 6666:1:2:3::10 eq bgp host 
7777:1:2:3::20 range 1300 1400
RP/0/RP0/CPU0:router# show ipv6 access-list Internetfilter
 
   
ipv6 access-list Internetfilter
  10 permit ipv6 3333:1:2:3::/64 any
  20 permit ipv6 4444:1:2:3::/64 any
  30 permit ipv6 5555:1:2:3::/64 any
  39 remark Block BGP traffic from a given host
  40 deny tcp host 6666:1:2:3::10 eq bgp host 7777:1:2:3::20 range 1300 1400

Related Commands 40 deny tcp host 6666:1:2:3::10 eq bgp host 7777:1:2:3::20 range 1300 1400

Command
Description

deny (IPv6)

Sets the deny conditions for an IPv6 access list.

ipv6 access-list

Defines an IPv6 access list and enters IPv6 access list configuration mode.

permit (IPv6)

Sets permit conditions for an IPv6 access list

resequence access-list ipv6

Changes the starting entry number of the first statement in an existing IPv6 access list, and the number by which subsequent statements are incremented.

show access-lists ipv6

Displays the contents of all current IPv6 access lists.


resequence access-list ipv4

To renumber existing statements and increment subsequent statements to allow a new IPv4 access list statement (permit, deny, or remark) to be added, use the resequence access-list ipv4 command in EXEC mode.

resequence access-list ipv4 name [base [increment]]

Syntax Description

name

Name of an IPv4 access list.

base

(Optional) Number of the first statement in the specified access list, which determines its order in the access list. Maximum value is 2147483644. Default is 10.

increment

(Optional) Number by which the base sequence number is incremented for subsequent statements. Maximum value is 2147483644. Default is 10.


Defaults

base: 10
increment: 10

Command Modes

EXEC

Command History

Release
Modification

Release 2.0

This command was introduced on the Cisco CRS-1.

Release 3.0

No modification.

Release 3.2

This command was supported on the Cisco XR 12000 Series Router. The command name was changed from resequence ipv4 access-list to resequence access-list ipv4. The increment maximum value was changed from 2147483646 to 2147483644.


Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.

Use the resequence access-list ipv4 command to add a permit, deny, or remark statement between consecutive entries in an existing IPv4 access list. Specify the first entry number (the base) and the increment by which to separate the entry numbers of the statements. The software renumbers the existing statements, thereby making room to add new statements with the unused entry numbers.

Examples

In the following example, suppose you have an existing access list:

ipv4 access-list marketing
  1 permit 10.1.1.1
  2 permit 10.2.0.0 0.0.255.255
  3 permit tcp host 10.2.2.2 255.255.0.0 any eq telnet
 
   

You want to add additional entries in the access list. First you resequence the entries, renumbering the statements starting with number 20 and an increment of 5, and then you have room for four additional statements between each of the existing statements:

RP/0/RP0/CPU0:router# resequence access-list ipv4 marketing 20 5
RP/0/RP0/CPU0:router# show access-lists ipv4 marketing
 
   
ipv4 access-list marketing
  20 permit 10.1.1.1
  25 permit 10.2.0.0 
  30 permit tcp host 10.2.2.2 255.255.0.0 any eq telnet
 
   

Now you add your new entries.

RP/0/RP0/CPU0:router(config)# ipv4 access-list marketing
RP/0/RP0/CPU0:router(config-ipv4-acl)# 3 remark Do not allow user1 to telnet out
RP/0/RP0/CPU0:router(config-ipv4-acl)# 4 deny tcp host 172.16.2.88 255.255.0.0 any eq 
telnet
RP/0/RP0/CPU0:router(config-ipv4-acl)# 29 remark Allow user2 to telnet out
RP/0/RP0/CPU0:router# show access-lists ipv4 marketing
 
   
ipv4 access-list marketing
  3 remark Do not allow user1 to telnet out
  4 deny tcp host 171.69.2.88 255.255.0.0 any eq telnet
  20 permit 10.1.1.1
  25 permit 10.2.0.0
  29 remark Allow user2 to telnet out
  30 permit tcp host 10.2.2.2 255.255.0.0 any eq telnet

Related Commands

Command
Description

deny (IPv4)

Sets the deny conditions for an IPv4 access list.

ipv4 access-list

Defines an IPv4 access list and enters IPv4 access list configuration mode.

permit (IPv4)

Sets the permit conditions for an IPv4 access list

remark (IPv4)

Inserts a helpful remark about an IPv4 access list. entry

show access-lists ipv4

Displays the contents of all current IPv4 access lists.


resequence access-list ipv6

To renumber existing statements and increment subsequent statements to allow a new IPv6 access list statement (permit, deny, or remark) to be added, use the resequence access-list ipv6 command in EXEC mode.

resequence access-list ipv6 name [base [increment]]

Syntax Description

name

Name of an IPv6 access list.

base

(Optional) Number of the first statement in the specified access list, which determines its order in the access list. Maximum value is 2147483646. Default is 10.

increment

(Optional) Number by which the base sequence number is incremented for subsequent statements. Maximum value is 2147483644. Default is 10.


Defaults

base: 10
increment: 10

Command Modes

EXEC

Command History

Release
Modification

Release 2.0

This command was introduced on the Cisco CRS-1.

Release 3.0

No modification.

Release 3.2

This command was supported on the Cisco XR 12000 Series Router.The command name was changed from resequence ipv6 access-list to resequence access-list ipv6. The increment maximum value was changed from 2147483646 to 2147483644.


Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.

The resequence access-list ipv6 command is similar to the resequence access-list ipv4 command, except that it is IPv6 specific.

Use the resequence access-list ipv6 command to add a permit, deny, or remark statement between consecutive entries in an existing IPv6 access list. Specify the first entry number (the base) and the increment by which to separate the entry numbers of the statements. The software renumbers the existing statements, thereby making room to add new statements with the unused entry numbers.

Examples

In the following example, suppose you have an existing access list:

ipv6 access-list Internetfilter
  10 permit ipv6 3333:1:2:3::/64 any
  20 permit ipv6 4444:1:2:3::/64 any
  30 permit ipv6 5555:1:2:3::/64 any
 
   

You want to add additional entries in the access list. First, you resequence the entries, renumbering the statements starting with number 20 and an increment of 5, and then you have room for four additional statements between each of the existing statements:

RP/0/RP0/CPU0:router# resequence access-list ipv6 Internetfilter 20 5
RP/0/RP0/CPU0:router# show access-lists ipv6 Internetfilter
 
   
ipv6 access-list Internetfilter
  20 permit ipv6 3333:1:2:3::/64 any
  25 permit ipv6 4444:1:2:3::/64 any
  30 permit ipv6 5555:1:2:3::/64 any
 
   

Now you add your new entries.

RP/0/RP0/CPU0:router(config)# ipv6 access-list Internetfilter
RP/0/RP0/CPU0:router(config-ipv6-acl)# 3 remark Block BGP traffic from a given host
RP/0/RP0/CPU0:router(config-ipv6-acl)# 4 deny tcp host 6666:1:2:3::10 eq bgp host 
7777:1:2:3::20 range 1300 1400
RP/0/RP0/CPU0:router# show access-lists ipv6 Internetfilter
 
   
ipv6 access-list Internetfilter
  3 remark Block BGP traffic from a given host
  4 deny tcp host 6666:1:2:3::10 eq bgp host 7777:1:2:3::20 range 1300 1404 deny tcp host 
171.69.2.88 255.255.0.0 any eq telnet
  20 permit ipv6 3333:1:2:3::/64 any
  25 permit ipv6 4444:1:2:3::/64 any
  30 permit ipv6 5555:1:2:3::/64 any

Related Commands

Command
Description

deny (IPv6)

Sets the deny conditions for an IPv6 access list.

ipv6 access-list

Defines an IPv6 access list and enters IPv6 access list configuration mode.

permit (IPv6)

Set permit conditions for an IPv6 access list.

remark (IPv6)

Inserts a helpful remark about an IPv6 access list entry.

show access-lists ipv6

Displays the contents of all current IPv6 access lists.


show access-lists ipv4

To display the contents of current IPv4 access lists, use the show access-lists ipv4 command in EXEC mode.

show access-lists ipv4 [access-list-name hardware {ingress | egress} {sequence number | location node-id} | summary [access-list-name] | access-list-name [sequence-number] | maximum [detail]]

Syntax Description

access-list-name

(Optional) Name of a particular IPv4 access list. The name cannot contain a space or quotation mark; it may contain numbers.

hardware

Identifies the access list as an access list for an interface.

ingress

Specifies an inbound interface.

egress

Specifies an outbound interface.

sequence number

(Optional) Sequence number of a particular IPv4 access list. Range is 1 to 2147483646.

location node-id

Location of a particular IPv4 access list. The node-id argument is entered in the rack/slot/module notation.

summary

Displays a summary of all current IPv4 access lists.

sequence-number

(Optional) Sequence number of a particular IPv4 access list. Range is 1 to 2147483646.

maximum

Displays the current maximum number of configurable IPv4 access control lists (ACLs) and access control entries (ACEs).

detail

(Optional) Displays complete out-of-resource (OOR) details.


Defaults

The default displays all IPv4 access lists.

Command Modes

EXEC

Command History

Release
Modification

Release 2.0

This command was introduced on the Cisco CRS-1.

Release 3.0

No modification.

Release 3.2

This command was supported on the Cisco XR 12000 Series Router. The command name was changed from show ipv4 access-lists to show access-lists ipv4.


Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.

Use the show access-lists ipv4 command to display the contents of all IPv4 access lists. To display the contents of a specific IPv4 access list, use the name argument. Use the sequence-number argument to specify the sequence number of the access list.

Use the hardware, ingress or egress, and location keywords to display the access list hardware contents and counters for all interfaces that use the specified access list in a given direction (ingress or egress). To display the contents of a specific access list entry, use the sequence number keyword and argument. The access group for an interface must be configured using the ipv4 access-group command for access list hardware counters to be enabled.

Use the show access-lists ipv4 summary command to display a summary of all current IPv4 access lists. To display a summary of a specific IPv4 access list, use the name argument.

Use the show access-lists ipv4 maximum detail command to display the OOR details for IPv4 access lists. OOR limits the number of ACLs and ACEs that can be configured in the system. When the limit is reached, configuration of new ACLs or ACEs is rejected.

Examples

In the following example, the contents of all IPv4 access lists are displayed:

RP/0/RP0/CPU0:router# show access-lists ipv4
 
   
ipv4 access-list 101
  10 deny udp any any eq ntp
  20 permit tcp any any
  30 permit udp any any eq tftp
  40 permit icmp any any
  50 permit udp any any eq domain
ipv4 access-list Internetfilter
  10 permit tcp any 172.16.0.0 0.0.255.255 eq telnet
  20 deny tcp any any
  30 deny udp any 172.18.0.0 0.0.255.255 lt 1024
  40 deny ipv4 any any log
 
   

In the following example, the contents of an access list named Internetfilter is displayed:

RP/0/RP0/CPU0:router# show access-lists ipv4 Internetfilter
 
   
ipv4 access-list Internetfilter
  10 permit tcp any 172.16.0.0 0.0.255.255 eq telnet
  20 deny tcp any any
  30 deny udp any 172.18.0.0 0.0.255.255 lt 1024
  40 deny ipv4 any any log
 
   

In the following example, the contents of an access list named acl_hw_1 are displayed:

RP/0/RP0/CPU0:router# show access-lists ipv4 acl_hw_1 hardware egress location 0/2/cp0
 
   
ipv4 access-list acl_hw_1
  10 permit icmp 192.168.36.0 0.0.0.255 any (251 hw matches)
  20 permit ip 172.16.3.0 0.0.255.255 any (29 hw matches)
  30 deny tcp any any (58 hw matches)
 
   

Table 2 describes the significant fields shown in the display.

Table 2 show access-lists ipv4 hardware Field Descriptions 

Field
Description

hw matches

Number of hardware matches.


In the following example, a summary of all IPv4 access lists are displayed:

RP/0/RP0/CPU0:router# show access-lists ipv4 summary
 
   
ACL Summary:
  Total ACLs configured: 3
  Total ACEs configured: 11
 
   

Table 3 describes the significant fields shown in the display.

Table 3 show access-lists ipv4 summary Field Descriptions 

Field
Description

Total ACLs configured

Number of configured IPv4 ACLs.

Total ACEs configured

Number of configured IPV4 ACEs.


In the following example, the OOR details of the IPv4 access lists are displayed:

RP/0/RP0/CPU0:router# show access-lists ipv4 maximum detail
 
   
Default max configurable acls :5000
Default max configurable aces :200000
Current configured acls       :1
Current configured aces       :2
Current max configurable acls :5000
Current max configurable aces :200000
Max configurable acls         :9000
Max configurable aces         :350000
 
   

Table 4 describes the significant fields shown in the display.

Table 4 show access-lists ipv4 maximum detail Field Descriptions 

Field
Description

Default max configurable acls

Default maximum number of configurable IPv4 ACLs allowed.

Default max configurable aces

Default maximum number of configurable IPv4 ACEs allowed.

Current configured acls

Number of configured IPv4 ACLs.

Current configured aces

Number of configured IPv4 ACEs.

Current max configurable acls

Configured maximum number of configurable IPv4 ACLs allowed.

Current max configurable aces

Configured maximum number of configurable IPv4 ACEs allowed.

Max configurable acls

Maximum number of configurable IPv4 ACLs allowed.

Max configurable aces

Maximum number of configurable IPv4 ACEs allowed.


Related Commands

Command
Description

clear access-list ipv4

Resets the IPv4 access list match counters.

copy access-list ipv4

Copies an existing IPv4 access list.

deny (IPv4)

Sets the deny conditions for an IPv4 access list.

ipv4 access-group

Filters incoming or outgoing IPv4 traffic on an interface.

ipv4 access-list

Defines an IPv4 access list and enters IPv4 access list configuration mode.

permit (IPv4)

Sets the permit conditions for an IPv4 access list

remark (IPv4)

Inserts a helpful remark about an IPv4 access list entry.

resequence access-list ipv4

Changes the starting entry number of the first statement in an existing IPv4 access list, and the number by which subsequent statements are incremented.


show access-lists ipv6

To display the contents of current IPv6 access lists, use the show access-lists ipv6 command in EXEC mode.

show access-lists ipv6 [access-list-name hardware {ingress | egress} {sequence number | location node-id} | summary [access-list-name] | access-list-name [sequence-number] | maximum [detail]]

Syntax Description

access-list-name

(Optional) Name of a particular IPv6 access list. The name cannot contain a space or quotation mark; it may contain numbers.

hardware

Identifies the access list as an access list for an interface.

ingress

Specifies an inbound interface.

egress

Specifies an outbound interface.

sequence number

(Optional) Sequence number of a particular IPv6 access list. Range is 1 to 2147483646.

location node-id

Location of a particular IPv4 access list. The node-id argument is entered in the rack/slot/module notation.

summary

Displays a summary of all current IPv6 access lists.

sequence-number

(Optional) Sequence number of a particular IPv6 access list. Range is 1 to 2147483646.

maximum

Displays the current maximum number of configurable IPv6 access control lists (ACLs) and access control entries (ACEs).

detail

(Optional) Displays complete out-of-resource (OOR) details.


Defaults

Displays all IPv6 access lists.

Command Modes

EXEC

Command History

Release
Modification

Release 2.0

This command was introduced on the Cisco CRS-1.

Release 3.0

No modification.

Release 3.2

This command was supported on the Cisco XR 12000 Series Router. The command name was changed from show ipv6 access-lists to show access-lists ipv6.


Usage Guidelines

To use this command, you must be in a user group associated with a task group that includes the proper task IDs. For detailed information about user groups and task IDs, see the Configuring AAA Services on Cisco IOS XR Software module of the Cisco IOS XR System Security Configuration Guide.

The show access-lists ipv6 command is similar to the show access-lists ipv4 command, except that it is IPv6 specific.

Use the show access-lists ipv6 command to display the contents of all IPv6 access lists. To display the contents of a specific IPv6 access list, use the name argument. Use the sequence-number argument to specify the sequence number of the access list.

Use the hardware, ingress or egress, and location keywords to display the access list hardware contents and counters for all interfaces that use the specified access list in a given direction (ingress or egress). To display the contents of a specific access list entry, use the sequence number keyword and argument. The access group for an interface must be configured using the ipv6 access-group command for access list hardware counters to be enabled.

Use the show access-lists ipv6 summary command to display a summary of all current IPv6 access lists. To display a summary of a specific IPv6 access list, use the name argument.

Use the show access-lists ipv6 maximum detail command to display the OOR details for IPv6 access lists. OOR limits the number of ACLs and ACEs that can be configured in the system. When the limit is reached, configuration of new ACLs or ACEs is rejected.

Examples

In the following example, the contents of all IPv6 access lists are displayed:

RP/0/RP0/CPU0:router# show access-lists ipv6
 
   
ipv6 access-list Internetfilter
  3 remark Block BGP traffic from a given host
  4 deny tcp host 6666:1:2:3::10 eq bgp host 7777:1:2:3::20 range 1300 1404 deny tcp host 
171.69.2.88 255.255.0.0 any eq telnet
  20 permit ipv6 3333:1:2:3::/64 any
  25 permit ipv6 4444:1:2:3::/64 any
  30 permit ipv6 5555:1:2:3::/64 any
ipv6 access-list marketing
  10 permit ipv6 7777:1:2:3::/64 any (51 matches)
  20 permit ipv6 8888:1:2:3::/64 any (26 matches)
  30 permit ipv6 9999:1:2:3::/64 any (5 matches)
 
   

In the following example, the contents of an access list named Internetfilter is displayed:

RP/0/RP0/CPU0:router# show access-lists ipv6 Internetfilter
 
   
ipv6 access-list Internetfilter
  3 remark Block BGP traffic from a given host
  4 deny tcp host 6666:1:2:3::10 eq bgp host 7777:1:2:3::20 range 1300 1404 deny tcp host 
171.69.2.88 255.255.0.0 any eq telnet
  20 permit ipv6 3333:1:2:3::/64 any
  25 permit ipv6 4444:1:2:3::/64 any
  30 permit ipv6 5555:1:2:3::/64 any
 
   

In the following example, the contents of an access list named acl_hw_1 is displayed:

RP/0/RP0/CPU0:router# show access-lists ipv6 acl_hw_1 hardware egress location 0/2/cp0
 
   
ipv6 access-list acl_hw_1
  10 permit icmp any any (251 hw matches)
  20 permit ipv6 3333:1:2:3::/64 any (29 hw matches)
  30 deny tcp any any (58 hw matches)
 
   

Table 5 describes the significant fields shown in the display.

Table 5 show access-lists ipv6 hardware Field Descriptions 

Field
Description

hw matches

Number of hardware matches.


In the following example, a summary of all IPv6 access lists is displayed:

RP/0/RP0/CPU0:router# show access-lists ipv6 summary
 
   
ACL Summary:
  Total ACLs configured: 3
  Total ACEs configured: 11
 
   

Table 6 describes the significant fields shown in the display.

Table 6 show access-lists ipv6 summary Field Descriptions 

Field
Description

Total ACLs configured

Number of configured IPv6 ACLs.

Total ACEs configured

Number of configured IPV6 ACEs.


In the following example, the OOR details of the IPv6 access lists are displayed:

RP/0/RP0/CPU0:router# show access-lists ipv6 maximum detail
 
   
Default max configurable acls :1000
Default max configurable aces :50000
Current configured acls       :1
Current configured aces       :2
Current max configurable acls :1000
Current max configurable aces :50000
Max configurable acls         :2000
Max configurable aces         :100000
 
   

Table 7 describes the significant fields shown in the display.

Table 7 show access-lists pv6 maximum detail Field Descriptions 

Field
Description

Default max configurable acls

Default maximum number of configurable IPv6 ACLs allowed.

Default max configurable aces

Default maximum number of configurable IPv6 ACEs allowed.

Current configured acls

Number of configured IPv6 ACLs.

Current configured aces

Number of configured IPv6 ACEs.

Current max configurable acls

Configured maximum number of configurable IPv6 ACLs allowed.

Current max configurable aces

Configured maximum number of configurable IPv6 ACEs allowed.

Max configurable acls

Maximum number of configurable IPv6 ACLs allowed.

Max configurable aces

Maximum number of configurable IPv6 ACEs allowed.


Related Commands

Command
Description

copy access-list ipv6

Copies an existing IPv6 access list.

deny (IPv6)

Sets the deny conditions for an IPv6 access list.

ipv6 access-group

Filters incoming or outgoing IPv6 traffic on an interface.

ipv6 access-list

Defines an IPv6 access list and enters IPv6 access list configuration mode.

permit (IPv6)

Set permit conditions for an IPv6 access list.

remark (IPv6)

Inserts a helpful remark about an IPv6 access list entry.

resequence access-list ipv6

Changes the starting entry number of the first statement in an existing IPv4 access list, and the number by which subsequent statements are incremented.