Cisco Nexus 6000 Series NX-OS Security Command Reference
D Commands
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D Commands

Table Of Contents

D Commands

deadtime

deny (ARP)

deny icmp (IPv4)

deny igmp (IPv4)

deny ip (IPv4)

deny tcp (IPv4)

deny udp (IPv4)

deny icmp (IPv6)

deny ipv6 (IPv6)

deny sctp (IPv6)

deny tcp (IPv6)

deny udp (IPv6)

deny (MAC)

description (user role)


D Commands


This chapter describes the Cisco NX-OS security commands that begin with D.

deadtime

To configure the dead-time interval for a RADIUS or TACACS+ server group, use the deadtime command. To revert to the default, use the no form of this command.

deadtime minutes

no deadtime minutes

Syntax Description

minutes

Number of minutes for the interval. The range is from 0 to 1440 minutes. Setting the dead-time interval to 0 disables the timer.


Command Default

0 minutes

Command Modes

RADlUS server group configuration
TACACS+ server group configuration

Command History

Release
Modification

6.0(2)N1(1)

This command was introduced.


Usage Guidelines

You must use the feature tacacs+ command before you configure TACACS.

Examples

This example shows how to set the dead-time interval to 2 minutes for a RADIUS server group:

switch(config)# aaa group server radius RadServer
switch(config-radius)# deadtime 2
 
   

This example shows how to set the dead-time interval to 5 minutes for a TACACS+ server group:

switch(config)# aaa group server tacacs+ TacServer
switch(config-tacacs+)# deadtime 5
 
   

This example shows how to revert to the dead-time interval default:

switch(config)# aaa group server tacacs+ TacServer
switch(config-tacacs+)# no deadtime 5
 
   

Related Commands

Command
Description

aaa group server

Configures AAA server groups.

feature tacacs+

Enables TACACS+.

radius-server host

Configures a RADIUS server.

show radius-server groups

Displays RADIUS server group information.

show tacacs-server groups

Displays TACACS+ server group information.

tacacs-server host

Configures a TACACS+ server.


deny (ARP)

To create an ARP ACL rule that denies ARP traffic that matches its conditions, use the deny command. To remove a rule, use the no form of this command.

General Syntax

[sequence-number] deny ip {any | host sender-IP | sender-IP sender-IP-mask} mac any

no sequence-number

no deny ip {any | host sender-IP | sender-IP sender-IP-mask} mac any

Syntax Description

sequence-number

(Optional) Sequence number of the deny command, which causes the device to insert the command in that numbered position in the access list. Sequence numbers maintain the order of rules within an ACL.

A sequence number can be any integer between 1 and 4294967295.

By default, the first rule in an ACL has a sequence number of 10.

If you do not specify a sequence number, the device adds the rule to the end of the ACL and assigns a sequence number that is 10 greater than the sequence number of the preceding rule.

Use the resequence command to reassign sequence numbers to rules.

ip

Introduces the IP address portion of the rule.

any

(Optional) Specifies that any host matches the part of the rule that contains the any keyword. You can use the any to specify the sender IP address, target IP address, sender MAC address, and target MAC address.

host sender-IP

(Optional) Specifies that the rule matches ARP packets only when the sender IP address in the packet matches the value of the sender-IP argument. Valid values for the sender-IP argument are IPv4 addresses in dotted-decimal format.

sender-IP sender-IP-mask

(Optional) IPv4 address and mask for the set of IPv4 addresses that the sender IP address in the packet can match. The sender-IP and sender-IP-mask argument must be given in dotted-decimal format. Specifying 255.255.255.255 as the sender-IP-mask argument is the equivalent of using the host keyword.

mac

Introduces the MAC address portion of the rule.


Command Default

None

Command Modes

ARP ACL configuration mode

Command History

Release
Modification

6.0(2)N1(1)

This command was introduced.


Usage Guidelines


Note An ARP access list is supported only for Control Plane Policing (CoPP). The deny command is ignored for CoPP ARP ACLs.


A newly created ARP ACL contains no rules.

If you do not specify a sequence number, the device assigns a sequence number to the rule that is 10 greater than the last rule in the ACL.

When the device applies an ARP ACL to a packet, it evaluates the packet with every rule in the ACL. The device enforces the first rule that has conditions that are satisfied by the packet. When the conditions of more than one rule are satisfied, the device enforces the rule with the lowest sequence number.

Examples

This example shows how to enter ARP access list configuration mode for an ARP ACL named copp-arp-acl and add a rule that denies ARP request messages that contain a sender IP address that is within the 192.0.32.14/24 subnet and associate that with the copp-arp-acl class:

switch# configure terminal
switch(config)# arp access-list copp-arp-acl
switch(config-arp-acl)# deny ip 192.0.32.14 255.255.255.0 mac any
switch(config-arp-acl)#
 
   

Related Commands

Command
Description

arp access-list

Configures an ARP ACL.

permit (ARP)

Configures a permit rule in an ARP ACL.

remark

Configures a remark in an ACL.

show arp access-lists

Displays all ARP ACLs or one ARP ACL.


deny icmp (IPv4)

To create an access control list (ACL) rule that denies ICMP IPv4 traffic matching its conditions, use the deny command. To remove a rule, use the no form of this command.

[sequence-number] deny icmp source destination [icmp-message | dscp dscp| log | precedence precedence | fragments]

no deny icmp source destination [icmp-message | dscp dscp | log | precedence precedence | fragments]

no sequence-number

Syntax Description

sequence-number

(Optional) Sequence number of the deny command, which causes the switch to insert the command in that numbered position in the access list. Sequence numbers maintain the order of rules within an ACL.

A sequence number can be any integer between 1 and 4294967295.

By default, the first rule in an ACL has a sequence number of 10.

If you do not specify a sequence number, the switch adds the rule to the end of the ACL and assigns to it a sequence number that is 10 greater than the sequence number of the preceding rule.

Use the resequence command to reassign sequence numbers to rules.

source

Source IPv4 addresses that the rule matches. For details about the methods that you can use to specify this argument, see the "Source and Destination" section in the "Usage Guidelines" section.

destination

Destination IPv4 addresses that the rule matches. For details about the methods that you can use to specify this argument, see the "Source and Destination" section in the "Usage Guidelines" section.

icmp-message

(Optional) Rule that matches only packets of the specified ICMP message type. This argument can be an integer from 0 to 255 or one of the keywords listed under the "ICMP Message Types" section in the "Usage Guidelines" section.

dscp dscp

(Optional) Specifies that the rule matches only those packets with the specified 6-bit differentiated services value in the DSCP field of the IP header. The dscp argument can be one of the following numbers or keywords:

0-63—The decimal equivalent of the 6 bits of the DSCP field. For example, if you specify 10, the rule matches only those packets that have the following bits in the DSCP field: 001010.

af11—Assured Forwarding (AF) class 1, low drop probability (001010)

af12—AF class 1, medium drop probability (001100)

af13—AF class 1, high drop probability (001110)

af21—AF class 2, low drop probability (010010)

af22—AF class 2, medium drop probability (010100)

af23—AF class 2, high drop probability (010110)

af31—AF class 3, low drop probability (011010)

af32—AF class 3, medium drop probability (011100)

af33—AF class 3, high drop probability (011110)

af41—AF class 4, low drop probability (100010)

af42—AF class 4, medium drop probability (100100)

af43—AF class 4, high drop probability (100110)

cs1—Class-selector (CS) 1, precedence 1 (001000)

cs2—CS2, precedence 2 (010000)

cs3—CS3, precedence 3 (011000)

cs4—CS4, precedence 4 (100000)

cs5—CS5, precedence 5 (101000)

cs6—CS6, precedence 6 (110000)

cs7—CS7, precedence 7 (111000)

default—Default DSCP value (000000)

ef—Expedited Forwarding (101110)

fragments

(Optional) Specifies that the rule matches only those packets that are noninitial fragments. You cannot specify this keyword in the same rule that you specify Layer 4 options, such as a TCP port number, because the information that the switch requires to evaluate those options is contained only in initial fragments.

log

(Optional) Specifies that the device generates an informational logging message about each packet that matches the rule. The message includes the following information:

Protocol

Source and destination addresses

Source and destination port numbers, if applicable

precedence precedence

(Optional) Specifies that the rule matches only packets that have an IP Precedence field with the value specified by the precedence argument. The precedence argument can be a number or a keyword as follows:

0-7—Decimal equivalent of the 3 bits of the IP Precedence field. For example, if you specify 3, the rule matches only packets that have the following bits in the DSCP field: 011.

critical—Precedence 5 (101)

flash—Precedence 3 (011)

flash-override—Precedence 4 (100)

immediate—Precedence 2 (010)

internet—Precedence 6 (110)

network—Precedence 7 (111)

priority—Precedence 1 (001)

routine—Precedence 0 (000)


Command Default

A newly created IPv4 ACL contains no rules.

If you do not specify a sequence number, the switch assigns the rule a sequence number that is 10 greater than the last rule in the ACL.

Command Modes

IPv4 ACL configuration

Command History

Release
Modification

6.0(2)N1(1)

This command was introduced.


Usage Guidelines

When the switch applies an IPv4 ACL to a packet, it evaluates the packet with every rule in the ACL. The switch enforces the first rule whose conditions are satisfied by the packet. When the conditions of more than one rule are satisfied, the switch enforces the rule with the lowest sequence number.

Source and Destination

You can specify the source and destination arguments in one of several ways. In each rule, the method that you use to specify one of these arguments does not affect how you specify the other argument. When you configure a rule, use the following methods to specify the source and destination arguments:

Address and network wildcard—You can use an IPv4 address followed by a network wildcard to specify a host or a network as a source or destination. The syntax is as follows:

IPv4-address network-wildcard 
 
   

This example shows how to specify the source argument with the IPv4 address and network wildcard for the 192.168.67.0 subnet:

switch(config-acl)# deny icmp 192.168.67.0 0.0.0.255 any 
 
   

Address and variable-length subnet mask—You can use an IPv4 address followed by a variable-length subnet mask (VLSM) to specify a host or a network as a source or destination. The syntax is as follows:

IPv4-address/prefix-len 
 
   

This example shows how to specify the source argument with the IPv4 address and VLSM for the 192.168.67.0 subnet:

switch(config-acl)# deny icmp 192.168.67.0/24 any 
 
   

Host address—You can use the host keyword and an IPv4 address to specify a host as a source or destination. The syntax is as follows:

host IPv4-address 
 
   

This syntax is equivalent to IPv4-address/32 and IPv4-address 0.0.0.0.

This example shows how to specify the source argument with the host keyword and the 192.168.67.132 IPv4 address:

switch(config-acl)# deny icmp host 192.168.67.132 any 
 
   

Any address—You can use the any keyword to specify that a source or destination is any IPv4 address. For examples of the use of the any keyword, see the examples in this section. Each example shows how to specify a source or destination by using the any keyword.

ICMP Message Types

The icmp-message argument can be the ICMP message number, which is an integer from 0 to 255. It can also be one of the following keywords:

administratively-prohibited—Administratively prohibited

alternate-address—Alternate address

conversion-error—Datagram conversion

dod-host-prohibited—Host prohibited

dod-net-prohibited—Net prohibited

echo—Echo (ping)

echo-reply—Echo reply

general-parameter-problem—Parameter problem

host-isolated—Host isolated

host-precedence-unreachable—Host unreachable for precedence

host-redirect—Host redirect

host-tos-redirect—Host redirect for ToS

host-tos-unreachable—Host unreachable for ToS

host-unknown—Host unknown

host-unreachable—Host unreachable

information-reply—Information replies

information-request—Information requests

mask-reply—Mask replies

mask-request—Mask requests

mobile-redirect—Mobile host redirect

net-redirect—Network redirect

net-tos-redirect—Net redirect for ToS

net-tos-unreachable—Network unreachable for ToS

net-unreachable—Net unreachable

network-unknown—Network unknown

no-room-for-option—Parameter required but no room

option-missing—Parameter required but not present

packet-too-big—Fragmentation needed and DF set

parameter-problem—All parameter problems

port-unreachable—Port unreachable

precedence-unreachable—Precedence cutoff

protocol-unreachable—Protocol unreachable

reassembly-timeout—Reassembly timeout

redirect—All redirects

router-advertisement—Router discovery advertisements

router-solicitation—Router discovery solicitations

source-quench—Source quenches

source-route-failed—Source route failed

time-exceeded—All time-exceeded messages

timestamp-reply—Time-stamp replies

timestamp-request—Time-stamp requests

traceroute—Traceroute

ttl-exceeded—TTL exceeded

unreachable—All unreachables

Examples

This example shows how to configure an IPv4 ACL named acl-lab-01 with rules that deny all ICMP traffic from the 10.23.0.0 and 192.168.37.0 networks to the 10.176.0.0 network and a final rule that permits all other IPv4 traffic:

switch(config)# ip access-list acl-lab-01 
switch(config-acl)# deny icmp 10.23.0.0/16 10.176.0.0/16 
switch(config-acl)# deny icmp 192.168.37.0/16 10.176.0.0/16 
switch(config-acl)# permit ip any any 
 
   

Related Commands

Command
Description

ip access-list

Configures an IPv4 ACL.

permit (IPv4)

Configures a permit rule in an IPv4 ACL.

remark

Configures a remark in an IPv4 ACL.

show ip access-list

Displays all IPv4 ACLs or one IPv4 ACL.


deny igmp (IPv4)

To create an access control list (ACL) rule that denies IGMP IPv4 traffic matching its conditions, use the deny command. To remove a rule, use the no form of this command.

[sequence-number] deny igmp source destination [igmp-message | dscp dscp | precedence precedence | fragments | log]

no deny igmp source destination [igmp-message | dscp dscp | precedence precedence | fragments | log]

no sequence-number

Syntax Description

sequence-number

(Optional) Sequence number of the deny command, which causes the switch to insert the command in that numbered position in the access list. Sequence numbers maintain the order of rules within an ACL.

A sequence number can be any integer between 1 and 4294967295.

By default, the first rule in an ACL has a sequence number of 10.

If you do not specify a sequence number, the switch adds the rule to the end of the ACL and assigns to it a sequence number that is 10 greater than the sequence number of the preceding rule.

Use the resequence command to reassign sequence numbers to rules.

source

Source IPv4 addresses that the rule matches. For details about the methods that you can use to specify this argument, see the "Source and Destination" section in the "Usage Guidelines" section.

destination

Destination IPv4 addresses that the rule matches. For details about the methods that you can use to specify this argument, see the "Source and Destination" section in the "Usage Guidelines" section.

igmp-message

(Optional) Rule that matches only packets of the specified IGMP message type. The igmp-message argument can be the IGMP message number, which is an integer from 0 to 15. It can also be one of the following keywords:

dvmrp—Distance Vector Multicast Routing Protocol

host-query—Host query

host-report—Host report

pim—Protocol Independent Multicast

trace—Multicast trace

dscp dscp

(Optional) Specifies that the rule matches only those packets with the specified 6-bit differentiated services value in the DSCP field of the IP header. The dscp argument can be one of the following numbers or keywords:

0-63—The decimal equivalent of the 6 bits of the DSCP field. For example, if you specify 10, the rule matches only those packets that have the following bits in the DSCP field: 001010.

af11—Assured Forwarding (AF) class 1, low drop probability (001010)

af12—AF class 1, medium drop probability (001100)

af13—AF class 1, high drop probability (001110)

af21—AF class 2, low drop probability (010010)

af22—AF class 2, medium drop probability (010100)

af23—AF class 2, high drop probability (010110)

af31—AF class 3, low drop probability (011010)

af32—AF class 3, medium drop probability (011100)

af33—AF class 3, high drop probability (011110)

af41—AF class 4, low drop probability (100010)

af42—AF class 4, medium drop probability (100100)

af43—AF class 4, high drop probability (100110)

cs1—Class-selector (CS) 1, precedence 1 (001000)

cs2—CS2, precedence 2 (010000)

cs3—CS3, precedence 3 (011000)

cs4—CS4, precedence 4 (100000)

cs5—CS5, precedence 5 (101000)

cs6—CS6, precedence 6 (110000)

cs7—CS7, precedence 7 (111000)

default—Default DSCP value (000000)

ef—Expedited Forwarding (101110)

fragments

(Optional) Specifies that the rule matches only those packets that are noninitial fragments. You cannot specify this keyword in the same rule that you specify Layer 4 options, such as a TCP port number, because the information that the switch requires to evaluate those options is contained only in initial fragments.

log

(Optional) Specifies that the device generates an informational logging message about each packet that matches the rule. The message includes the following information:

Protocol

Source and destination addresses

Source and destination port numbers, if applicable

precedence precedence

(Optional) Specifies that the rule matches only packets that have an IP Precedence field with the value specified by the precedence argument. The precedence argument can be a number or a keyword as follows:

0-7—Decimal equivalent of the 3 bits of the IP Precedence field. For example, if you specify 3, the rule matches only packets that have the following bits in the DSCP field: 011.

critical—Precedence 5 (101)

flash—Precedence 3 (011)

flash-override—Precedence 4 (100)

immediate—Precedence 2 (010)

internet—Precedence 6 (110)

network—Precedence 7 (111)

priority—Precedence 1 (001)

routine—Precedence 0 (000)


Command Default

A newly created IPv4 ACL contains no rules.

If you do not specify a sequence number, the switch assigns the rule a sequence number that is 10 greater than the last rule in the ACL.

Command Modes

IPv4 ACL configuration

Command History

Release
Modification

6.0(2)N1(1)

This command was introduced.


Usage Guidelines

When the switch applies an IPv4 ACL to a packet, it evaluates the packet with every rule in the ACL. The switch enforces the first rule whose conditions are satisfied by the packet. When the conditions of more than one rule are satisfied, the switch enforces the rule with the lowest sequence number.

Source and Destination

You can specify the source and destination arguments in one of several ways. In each rule, the method that you use to specify one of these arguments does not affect how you specify the other argument. When you configure a rule, use the following methods to specify the source and destination arguments:

Address and network wildcard—You can use an IPv4 address followed by a network wildcard to specify a host or a network as a source or destination. The syntax is as follows:

IPv4-address network-wildcard 
 
   

This example shows how to specify the source argument with the IPv4 address and network wildcard for the 192.168.67.0 subnet:

switch(config-acl)# deny igmp 192.168.67.0 0.0.0.255 any 
 
   

Address and variable-length subnet mask—You can use an IPv4 address followed by a variable-length subnet mask (VLSM) to specify a host or a network as a source or destination. The syntax is as follows:

IPv4-address/prefix-len 
 
   

This example shows how to specify the source argument with the IPv4 address and VLSM for the 192.168.67.0 subnet:

switch(config-acl)# deny igmp 192.168.67.0/24 any 
 
   

Host address—You can use the host keyword and an IPv4 address to specify a host as a source or destination. The syntax is as follows:

host IPv4-address 
 
   

This syntax is equivalent to IPv4-address/32 and IPv4-address 0.0.0.0.

This example shows how to specify the source argument with the host keyword and the 192.168.67.132 IPv4 address:

switch(config-acl)# deny igmp host 192.168.67.132 any 
 
   

Any address—You can use the any keyword to specify that a source or destination is any IPv4 address. For examples of the use of the any keyword, see the examples in this section. Each example shows how to specify a source or destination by using the any keyword.

Examples

This example shows how to configure an IPv4 ACL named acl-lab-01 with rules that deny all IGMP traffic from the 10.23.0.0 and 192.168.37.0 networks to the 10.176.0.0 network and a final rule that permits all other IPv4 traffic:

switch(config)# ip access-list acl-lab-01 
switch(config-acl)# deny igmp 10.23.0.0/16 10.176.0.0/16 
switch(config-acl)# deny igmp 192.168.37.0/16 10.176.0.0/16 
switch(config-acl)# permit ip any any 
 
   

Related Commands

Command
Description

ip access-list

Configures an IPv4 ACL.

permit (IPv4)

Configures a permit rule in an IPv4 ACL.

remark

Configures a remark in an IPv4 ACL.

show ip access-list

Displays all IPv4 ACLs or one IPv4 ACL.


deny ip (IPv4)

To create an access control list (ACL) rule that denies IPv4 traffic matching its conditions, use the deny command. To remove a rule, use the no form of this command.

[sequence-number] deny ip source destination [dscp dscp | fragments | log | precedence precedence]

no deny ip source destination [dscp dscp | fragments | log | precedence precedence]

no sequence-number

Syntax Description

sequence-number

(Optional) Sequence number of the deny command, which causes the switch to insert the command in that numbered position in the access list. Sequence numbers maintain the order of rules within an ACL.

A sequence number can be any integer between 1 and 4294967295.

By default, the first rule in an ACL has a sequence number of 10.

If you do not specify a sequence number, the switch adds the rule to the end of the ACL and assigns to it a sequence number that is 10 greater than the sequence number of the preceding rule.

Use the resequence command to reassign sequence numbers to rules.

source

Source IPv4 addresses that the rule matches. For details about the methods that you can use to specify this argument, see the "Source and Destination" section in the "Usage Guidelines" section.

destination

Destination IPv4 addresses that the rule matches. For details about the methods that you can use to specify this argument, see the "Source and Destination" section in the "Usage Guidelines" section.

dscp dscp

(Optional) Specifies that the rule matches only those packets with the specified 6-bit differentiated services value in the DSCP field of the IP header. The dscp argument can be one of the following numbers or keywords:

0-63—The decimal equivalent of the 6 bits of the DSCP field. For example, if you specify 10, the rule matches only those packets that have the following bits in the DSCP field: 001010.

af11—Assured Forwarding (AF) class 1, low drop probability (001010)

af12—AF class 1, medium drop probability (001100)

af13—AF class 1, high drop probability (001110)

af21—AF class 2, low drop probability (010010)

af22—AF class 2, medium drop probability (010100)

af23—AF class 2, high drop probability (010110)

af31—AF class 3, low drop probability (011010)

af32—AF class 3, medium drop probability (011100)

af33—AF class 3, high drop probability (011110)

af41—AF class 4, low drop probability (100010)

af42—AF class 4, medium drop probability (100100)

af43—AF class 4, high drop probability (100110)

cs1—Class-selector (CS) 1, precedence 1 (001000)

cs2—CS2, precedence 2 (010000)

cs3—CS3, precedence 3 (011000)

cs4—CS4, precedence 4 (100000)

cs5—CS5, precedence 5 (101000)

cs6—CS6, precedence 6 (110000)

cs7—CS7, precedence 7 (111000)

default—Default DSCP value (000000)

ef—Expedited Forwarding (101110)

fragments

(Optional) Specifies that the rule matches only those packets that are noninitial fragments. You cannot specify this keyword in the same rule that you specify Layer 4 options, such as a TCP port number, because the information that the switch requires to evaluate those options is contained only in initial fragments.

log

(Optional) Specifies that the device generates an informational logging message about each packet that matches the rule. The message includes the following information:

Protocol

Source and destination addresses

Source and destination port numbers, if applicable

precedence precedence

(Optional) Specifies that the rule matches only packets that have an IP Precedence field with the value specified by the precedence argument. The precedence argument can be a number or a keyword as follows:

0-7—Decimal equivalent of the 3 bits of the IP Precedence field. For example, if you specify 3, the rule matches only packets that have the following bits in the DSCP field: 011.

critical—Precedence 5 (101)

flash—Precedence 3 (011)

flash-override—Precedence 4 (100)

immediate—Precedence 2 (010)

internet—Precedence 6 (110)

network—Precedence 7 (111)

priority—Precedence 1 (001)

routine—Precedence 0 (000)


Command Default

A newly created IPv4 ACL contains no rules.

If you do not specify a sequence number, the switch assigns the rule a sequence number that is 10 greater than the last rule in the ACL.

Command Modes

IPv4 ACL configuration

Command History

Release
Modification

6.0(2)N1(1)

This command was introduced.


Usage Guidelines

When the switch applies an IPv4 ACL to a packet, it evaluates the packet with every rule in the ACL. The switch enforces the first rule whose conditions are satisfied by the packet. When the conditions of more than one rule are satisfied, the switch enforces the rule with the lowest sequence number.

Source and Destination

You can specify the source and destination arguments in one of several ways. In each rule, the method that you use to specify one of these arguments does not affect how you specify the other argument. When you configure a rule, use the following methods to specify the source and destination arguments:

Address and network wildcard—You can use an IPv4 address followed by a network wildcard to specify a host or a network as a source or destination. The syntax is as follows:

IPv4-address network-wildcard 
 
   

This example shows how to specify the source argument with the IPv4 address and network wildcard for the 192.168.67.0 subnet:

switch(config-acl)# deny ip 192.168.67.0 0.0.0.255 any 
 
   

Address and variable-length subnet mask—You can use an IPv4 address followed by a variable-length subnet mask (VLSM) to specify a host or a network as a source or destination. The syntax is as follows:

IPv4-address/prefix-len 
 
   

This example shows how to specify the source argument with the IPv4 address and VLSM for the 192.168.67.0 subnet:

switch(config-acl)# deny ip 192.168.67.0/24 any 
 
   

Host address—You can use the host keyword and an IPv4 address to specify a host as a source or destination. The syntax is as follows:

host IPv4-address 
 
   

This syntax is equivalent to IPv4-address/32 and IPv4-address 0.0.0.0.

This example shows how to specify the source argument with the host keyword and the 192.168.67.132 IPv4 address:

switch(config-acl)# deny ip host 192.168.67.132 any 
 
   

Any address—You can use the any keyword to specify that a source or destination is any IPv4 address. For examples of the use of the any keyword, see the examples in this section. Each example shows how to specify a source or destination by using the any keyword.

Examples

This example shows how to configure an IPv4 ACL named acl-lab-01 with rules that deny all IPv4 traffic from the 10.23.0.0 and 192.168.37.0 networks to the 10.176.0.0 network:

switch(config)# ip access-list acl-lab-01 
switch(config-acl)# deny ip 10.23.0.0/16 10.176.0.0/16 
switch(config-acl)# deny ip 192.168.37.0/16 10.176.0.0/16 
 
   

Related Commands

Command
Description

ip access-list

Configures an IPv4 ACL.

permit (IPv4)

Configures a permit rule in an IPv4 ACL.

remark

Configures a remark in an IPv4 ACL.

show ip access-list

Displays all IPv4 ACLs or one IPv4 ACL.


deny tcp (IPv4)

To create an access control list (ACL) rule that denies TCP IPv4 traffic matching its conditions, use the deny command. To remove a rule, use the no form of this command.

General Syntax

[sequence-number] deny tcp source [operator port [port] | portgroup portgroup] destination [operator port [port] | portgroup portgroup] [dscp dscp | established | flags | fragments | log | precedence precedence]

no deny tcp source [operator port [port] | portgroup portgroup] destination [operator port [port] | portgroup portgroup] [dscp dscp | established | flags | fragments | log | precedence precedence]

no sequence-number

Syntax Description

sequence-number

(Optional) Sequence number of the deny command, which causes the switch to insert the command in that numbered position in the access list. Sequence numbers maintain the order of rules within an ACL.

A sequence number can be any integer between 1 and 4294967295.

By default, the first rule in an ACL has a sequence number of 10.

If you do not specify a sequence number, the switch adds the rule to the end of the ACL and assigns to it a sequence number that is 10 greater than the sequence number of the preceding rule.

Use the resequence command to reassign sequence numbers to rules.

source

Source IPv4 addresses that the rule matches. For details about the methods that you can use to specify this argument, see the "Source and Destination"section in the "Usage Guidelines" section.

destination

Destination IPv4 addresses that the rule matches. For details about the methods that you can use to specify this argument, see the "Source and Destination"section in the "Usage Guidelines" section.

operator port [port]

(Optional) Rule that matches only packets that are from a source port or sent to a destination port that satisfies the conditions of the operator and port arguments. Whether these arguments apply to a source port or a destination port depends upon whether you specify them after the source argument or after the destination argument.

The port argument can be the name or the number of a TCP port. Valid numbers are integers from 0 to 65535. For listings of valid port names, see the "TCP Port Names" section in the "Usage Guidelines" section.

A second port argument is required only when the operator argument is a range.

The operator argument must be one of the following keywords:

eq—Matches only if the port in the packet is equal to the port argument.

gt—Matches only if the port in the packet is greater than the port argument.

lt—Matches only if the port in the packet is less than the port argument.

neq—Matches only if the port in the packet is not equal to the port argument.

range—Requires two port arguments and matches only if the port in the packet is equal to or greater than the first port argument and equal to or less than the second port argument.

portgroup portgroup

(Optional) Specifies that the rule matches only packets that are from a source port or to a destination port that is a member of the IP port-group object specified by the portgroup argument. Whether the port-group object applies to a source port or a destination port depends upon whether you specify it after the source argument or after the destination argument.

Use the object-group ip port command to create and change IP port-group objects.

dscp dscp

(Optional) Specifies that the rule matches only those packets with the specified 6-bit differentiated services value in the DSCP field of the IP header. The dscp argument can be one of the following numbers or keywords:

0-63—The decimal equivalent of the 6 bits of the DSCP field. For example, if you specify 10, the rule matches only those packets that have the following bits in the DSCP field: 001010.

af11—Assured Forwarding (AF) class 1, low drop probability (001010)

af12—AF class 1, medium drop probability (001100)

af13—AF class 1, high drop probability (001110)

af21—AF class 2, low drop probability (010010)

af22—AF class 2, medium drop probability (010100)

af23—AF class 2, high drop probability (010110)

af31—AF class 3, low drop probability (011010)

af32—AF class 3, medium drop probability (011100)

af33—AF class 3, high drop probability (011110)

af41—AF class 4, low drop probability (100010)

af42—AF class 4, medium drop probability (100100)

af43—AF class 4, high drop probability (100110)

cs1—Class-selector (CS) 1, precedence 1 (001000)

cs2—CS2, precedence 2 (010000)

cs3—CS3, precedence 3 (011000)

cs4—CS4, precedence 4 (100000)

cs5—CS5, precedence 5 (101000)

cs6—CS6, precedence 6 (110000)

cs7—CS7, precedence 7 (111000)

default—Default DSCP value (000000)

ef—Expedited Forwarding (101110)

established

(Optional) Specifies that the rule matches only packets that belong to an established TCP connection. The switch considers TCP packets with the ACK or RST bits set to belong to an established connection.

flags

(Optional) Rule that matches only packets that have specific TCP control bit flags set. The value of the flags argument must be one or more of the following keywords:

ack

fin

psh

rst

syn

urg

fragments

(Optional) Specifies that the rule matches only those packets that are noninitial fragments. You cannot specify this keyword in the same rule that you specify Layer 4 options, such as a TCP port number, because the information that the switch requires to evaluate those options is contained only in initial fragments.

log

(Optional) Specifies that the device generates an informational logging message about each packet that matches the rule. The message includes the following information:

Protocol

Source and destination addresses

Source and destination port numbers, if applicable

precedence precedence

(Optional) Specifies that the rule matches only packets that have an IP Precedence field with the value specified by the precedence argument. The precedence argument can be a number or a keyword as follows:

0-7—Decimal equivalent of the 3 bits of the IP Precedence field. For example, if you specify 3, the rule matches only packets that have the following bits in the DSCP field: 011.

critical—Precedence 5 (101)

flash—Precedence 3 (011)

flash-override—Precedence 4 (100)

immediate—Precedence 2 (010)

internet—Precedence 6 (110)

network—Precedence 7 (111)

priority—Precedence 1 (001)

routine—Precedence 0 (000)


Command Default

A newly created IPv4 ACL contains no rules.

If you do not specify a sequence number, the switch assigns the rule a sequence number that is 10 greater than the last rule in the ACL.

Command Modes

IPv4 ACL configuration

Command History

Release
Modification

6.0(2)N1(1)

This command was introduced.


Usage Guidelines

When the switch applies an IPv4 ACL to a packet, it evaluates the packet with every rule in the ACL. The switch enforces the first rule whose conditions are satisfied by the packet. When the conditions of more than one rule are satisfied, the switch enforces the rule with the lowest sequence number.

Source and Destination

You can specify the source and destination arguments in one of several ways. In each rule, the method that you use to specify one of these arguments does not affect how you specify the other argument. When you configure a rule, use the following methods to specify the source and destination arguments:

Address and network wildcard—You can use an IPv4 address followed by a network wildcard to specify a host or a network as a source or destination. The syntax is as follows:

IPv4-address network-wildcard 
 
   

This example shows how to specify the source argument with the IPv4 address and network wildcard for the 192.168.67.0 subnet:

switch(config-acl)# deny tcp 192.168.67.0 0.0.0.255 any 
 
   

Address and variable-length subnet mask—You can use an IPv4 address followed by a variable-length subnet mask (VLSM) to specify a host or a network as a source or destination. The syntax is as follows:

IPv4-address/prefix-len 
 
   

This example shows how to specify the source argument with the IPv4 address and VLSM for the 192.168.67.0 subnet:

switch(config-acl)# deny tcp 192.168.67.0/24 any 
 
   

Host address—You can use the host keyword and an IPv4 address to specify a host as a source or destination. The syntax is as follows:

host IPv4-address 
 
   

This syntax is equivalent to IPv4-address/32 and IPv4-address 0.0.0.0.

This example shows how to specify the source argument with the host keyword and the 192.168.67.132 IPv4 address:

switch(config-acl)# deny tcp host 192.168.67.132 any 
 
   

Any address—You can use the any keyword to specify that a source or destination is any IPv4 address. For examples of the use of the any keyword, see the examples in this section. Each example shows how to specify a source or destination by using the any keyword.

TCP Port Names

When you specify the protocol argument as tcp, the port argument can be a TCP port number, which is an integer from 0 to 65535. It can also be one of the following keywords:

bgp—Border Gateway Protocol (179)

chargen—Character generator (19)

cmd—Remote commands (rcmd, 514)

daytime—Daytime (13)

discard—Discard (9)

domain—Domain Name Service (53)

drip—Dynamic Routing Information Protocol (3949)

echo—Echo (7)

exec—EXEC (rsh, 512)

finger—Finger (79)

ftp—File Transfer Protocol (21)

ftp-data—FTP data connections (2)

gopher—Gopher (7)

hostname—NIC hostname server (11)

ident—Ident Protocol (113)

irc—Internet Relay Chat (194)

klogin—Kerberos login (543)

kshell—Kerberos shell (544)

login—Login (rlogin, 513)

lpd—Printer service (515)

nntp—Network News Transport Protocol (119)

pim-auto-rp—PIM Auto-RP (496)

pop2—Post Office Protocol v2 (19)

pop3—Post Office Protocol v3 (11)

smtp—Simple Mail Transport Protocol (25)

sunrpc—Sun Remote Procedure Call (111)

tacacs—TAC Access Control System (49)

talk—Talk (517)

telnet—Telnet (23)

time—Time (37)

uucp—Unix-to-Unix Copy Program (54)

whois—WHOIS/NICNAME (43)

www—World Wide Web (HTTP, 8)

Examples

This example shows how to configure an IPv4 ACL named acl-lab-01 with rules that deny all TCP traffic from the 10.23.0.0 and 192.168.37.0 networks to the 10.176.0.0 network and a final rule that permits all other IPv4 traffic:

switch(config)# ip access-list acl-lab-01 
switch(config-acl)# deny tcp 10.23.0.0/16 10.176.0.0/16 
switch(config-acl)# deny tcp 192.168.37.0/16 10.176.0.0/16 
switch(config-acl)# permit ip any any 
 
   

Related Commands

Command
Description

ip access-list

Configures an IPv4 ACL.

permit (IPv4)

Configures a permit rule in an IPv4 ACL.

remark

Configures a remark in an IPv4 ACL.

show ip access-list

Displays all IPv4 ACLs or one IPv4 ACL.


deny udp (IPv4)

To create an access control list (ACL) rule that denies UDP IPv4 traffic matching its conditions, use the deny command. To remove a rule, use the no form of this command.

General Syntax

[sequence-number] deny udp source [operator port [port] | portgroup portgroup] destination [operator port [port] | portgroup portgroup] [dscp dscp | fragments | log | precedence precedence]

no deny udp source [operator port [port] | portgroup portgroup] destination [operator port [port] | portgroup portgroup] [dscp dscp | fragments | log | precedence precedence

no sequence-number

Syntax Description

sequence-number

(Optional) Sequence number of the deny command, which causes the switch to insert the command in that numbered position in the access list. Sequence numbers maintain the order of rules within an ACL.

A sequence number can be any integer between 1 and 4294967295.

By default, the first rule in an ACL has a sequence number of 10.

If you do not specify a sequence number, the switch adds the rule to the end of the ACL and assigns to it a sequence number that is 10 greater than the sequence number of the preceding rule.

Use the resequence command to reassign sequence numbers to rules.

source

Source IPv4 addresses that the rule matches. For details about the methods that you can use to specify this argument, see the "Source and Destination" section in the "Usage Guidelines" section.

destination

Destination IPv4 addresses that the rule matches. For details about the methods that you can use to specify this argument, see the "Source and Destination" section in the "Usage Guidelines" section.

operator port [port]

(Optional) Rule that matches only packets that are from a source port or sent to a destination port that satisfies the conditions of the operator and port arguments. Whether these arguments apply to a source port or a destination port depends upon whether you specify them after the source argument or after the destination argument.

The port argument can be the name or the number of a TCP or UDP port. Valid numbers are integers from 0 to 65535. For listings of valid port names, see "TCP Port Names" and "UDP Port Names" in the "Usage Guidelines" section.

A second port argument is required only when the operator argument is a range.

The operator argument must be one of the following keywords:

eq—Matches only if the port in the packet is equal to the port argument.

gt—Matches only if the port in the packet is greater than the port argument.

lt—Matches only if the port in the packet is less than the port argument.

neq—Matches only if the port in the packet is not equal to the port argument.

range—Requires two port arguments and matches only if the port in the packet is equal to or greater than the first port argument and equal to or less than the second port argument.

portgroup portgroup

(Optional) Specifies that the rule matches only packets that are from a source port or to a destination port that is a member of the IP port-group object specified by the portgroup argument. Whether the port-group object applies to a source port or a destination port depends upon whether you specify it after the source argument or after the destination argument.

Use the object-group ip port command to create and change IP port-group objects.

dscp dscp

(Optional) Specifies that the rule matches only those packets with the specified 6-bit differentiated services value in the DSCP field of the IP header. The dscp argument can be one of the following numbers or keywords:

0-63—The decimal equivalent of the 6 bits of the DSCP field. For example, if you specify 10, the rule matches only those packets that have the following bits in the DSCP field: 001010.

af11—Assured Forwarding (AF) class 1, low drop probability (001010)

af12—AF class 1, medium drop probability (001100)

af13—AF class 1, high drop probability (001110)

af21—AF class 2, low drop probability (010010)

af22—AF class 2, medium drop probability (010100)

af23—AF class 2, high drop probability (010110)

af31—AF class 3, low drop probability (011010)

af32—AF class 3, medium drop probability (011100)

af33—AF class 3, high drop probability (011110)

af41—AF class 4, low drop probability (100010)

af42—AF class 4, medium drop probability (100100)

af43—AF class 4, high drop probability (100110)

cs1—Class-selector (CS) 1, precedence 1 (001000)

cs2—CS2, precedence 2 (010000)

cs3—CS3, precedence 3 (011000)

cs4—CS4, precedence 4 (100000)

cs5—CS5, precedence 5 (101000)

cs6—CS6, precedence 6 (110000)

cs7—CS7, precedence 7 (111000)

default—Default DSCP value (000000)

ef—Expedited Forwarding (101110)

fragments

(Optional) Specifies that the rule matches only those packets that are noninitial fragments. You cannot specify this keyword in the same rule that you specify Layer 4 options, such as a TCP port number, because the information that the switch requires to evaluate those options is contained only in initial fragments.

log

(Optional) Specifies that the device generates an informational logging message about each packet that matches the rule. The message includes the following information:

Protocol

Source and destination addresses

Source and destination port numbers, if applicable

precedence precedence

(Optional) Specifies that the rule matches only packets that have an IP Precedence field with the value specified by the precedence argument. The precedence argument can be a number or a keyword as follows:

0-7—Decimal equivalent of the 3 bits of the IP Precedence field. For example, if you specify 3, the rule matches only packets that have the following bits in the DSCP field: 011.

critical—Precedence 5 (101)

flash—Precedence 3 (011)

flash-override—Precedence 4 (100)

immediate—Precedence 2 (010)

internet—Precedence 6 (110)

network—Precedence 7 (111)

priority—Precedence 1 (001)

routine—Precedence 0 (000)


Command Default

A newly created IPv4 ACL contains no rules.

If you do not specify a sequence number, the switch assigns the rule a sequence number that is 10 greater than the last rule in the ACL.

Command Modes

IPv4 ACL configuration

Command History

Release
Modification

6.0(2)N1(1)

This command was introduced.


Usage Guidelines

When the switch applies an IPv4 ACL to a packet, it evaluates the packet with every rule in the ACL. The switch enforces the first rule whose conditions are satisfied by the packet. When the conditions of more than one rule are satisfied, the switch enforces the rule with the lowest sequence number.

Source and Destination

You can specify the source and destination arguments in one of several ways. In each rule, the method that you use to specify one of these arguments does not affect how you specify the other argument. When you configure a rule, use the following methods to specify the source and destination arguments:

Address and network wildcard—You can use an IPv4 address followed by a network wildcard to specify a host or a network as a source or destination. The syntax is as follows:

IPv4-address network-wildcard 
 
   

This example shows how to specify the source argument with the IPv4 address and network wildcard for the 192.168.67.0 subnet:

switch(config-acl)# deny udp 192.168.67.0 0.0.0.255 any 
 
   

Address and variable-length subnet mask—You can use an IPv4 address followed by a variable-length subnet mask (VLSM) to specify a host or a network as a source or destination. The syntax is as follows:

IPv4-address/prefix-len 
 
   

This example shows how to specify the source argument with the IPv4 address and VLSM for the 192.168.67.0 subnet:

switch(config-acl)# deny udp 192.168.67.0/24 any 
 
   

Host address—You can use the host keyword and an IPv4 address to specify a host as a source or destination. The syntax is as follows:

host IPv4-address 
 
   

This syntax is equivalent to IPv4-address/32 and IPv4-address 0.0.0.0.

This example shows how to specify the source argument with the host keyword and the 192.168.67.132 IPv4 address:

switch(config-acl)# deny udp host 192.168.67.132 any 
 
   

Any address—You can use the any keyword to specify that a source or destination is any IPv4 address. For examples of the use of the any keyword, see the examples in this section. Each example shows how to specify a source or destination by using the any keyword.

UDP Port Names

When you specify the protocol argument as udp, the port argument can be a UDP port number, which is an integer from 0 to 65535. It can also be one of the following keywords:

biff—Biff (mail notification, comsat, 512)

bootpc—Bootstrap Protocol (BOOTP) client (68)

bootps—Bootstrap Protocol (BOOTP) server (67)

discard—Discard (9)

dnsix—DNSIX security protocol auditing (195)

domain—Domain Name Service (DNS, 53)

echo—Echo (7)

isakmp—Internet Security Association and Key Management Protocol (5)

mobile-ip—Mobile IP registration (434)

nameserver—IEN116 name service (obsolete, 42)

netbios-dgm—NetBIOS datagram service (138)

netbios-ns—NetBIOS name service (137)

netbios-ss—NetBIOS session service (139)

non500-isakmp—Internet Security Association and Key Management Protocol (45)

ntp—Network Time Protocol (123)

pim-auto-rp—PIM Auto-RP (496)

rip—Routing Information Protocol (router, in.routed, 52)

snmp—Simple Network Management Protocol (161)

snmptrap—SNMP Traps (162)

sunrpc—Sun Remote Procedure Call (111)

syslog—System Logger (514)

tacacs—TAC Access Control System (49)

talk—Talk (517)

tftp—Trivial File Transfer Protocol (69)

time—Time (37)

who—Who service (rwho, 513)

xdmcp—X Display Manager Control Protocol (177)

Examples

This example shows how to configure an IPv4 ACL named acl-lab-01 with rules that deny all UDP traffic from the 10.23.0.0 and 192.168.37.0 networks to the 10.176.0.0 network and a final rule that permits all other IPv4 traffic:

switch(config)# ip access-list acl-lab-01 
switch(config-acl)# deny udp 10.23.0.0/16 10.176.0.0/16 
switch(config-acl)# deny udp 192.168.37.0/16 10.176.0.0/16 
switch(config-acl)# permit ip any any 
 
   

Related Commands

Command
Description

ip access-list

Configures an IPv4 ACL.

permit (IPv4)

Configures a permit rule in an IPv4 ACL.

remark

Configures a remark in an IPv4 ACL.

show ip access-list

Displays all IPv4 ACLs or one IPv4 ACL.


deny icmp (IPv6)

To create an access control list (ACL) rule that denies ICMP IPv6 traffic matching its conditions, use the deny command. To remove a rule, use the no form of this command.

[sequence-number] deny icmp source destination [icmp-message | dscp dscp | flow-label flow-label-value | fragments]

no deny icmp source destination [icmp-message | dscp dscp | flow-label flow-label-value | fragments]

no sequence-number

Syntax Description

sequence-number

(Optional) Sequence number of the deny command, which causes the device to insert the command in that numbered position in the access list. Sequence numbers maintain the order of rules within an ACL.

A sequence number can be any integer between 1 and 4294967295.

By default, the first rule in an ACL has a sequence number of 10.

If you do not specify a sequence number, the device adds the rule to the end of the ACL and assigns a sequence number that is 10 greater than the sequence number of the preceding rule.

Use the resequence command to reassign sequence numbers to rules.

source

Source IPv6 addresses that the rule matches. For details about the methods that you can use to specify this argument, see the "Source and Destination" section in the "Usage Guidelines" section.

destination

Destination IPv6 addresses that the rule matches. For details about the methods that you can use to specify this argument, see the "Source and Destination" section in the "Usage Guidelines" section.

icmp-message

(Optional) ICMPv6 message type that the rule matches. This argument can be an integer from 0 to 255 or one of the keywords listed in the "ICMPv6 Message Types" section in the "Usage Guidelines" section.

dscp dscp

(Optional) Specifies that the rule matches only packets with the specified 6-bit differentiated services value in the DSCP field of the IPv6 header. The dscp argument can be one of the following numbers or keywords:

0-63—The decimal equivalent of the 6 bits of the DSCP field. For example, if you specify 10, the rule matches only packets that have the following bits in the DSCP field: 001010.

af11—Assured Forwarding (AF) class 1, low drop probability (001010)

af12—AF class 1, medium drop probability (001100)

af13—AF class 1, high drop probability (001110)

af21—AF class 2, low drop probability (010010)

af22—AF class 2, medium drop probability (010100)

af23—AF class 2, high drop probability (010110)

af31—AF class 3, low drop probability (011010)

af32—AF class 3, medium drop probability (011100)

af33—AF class 3, high drop probability (011110)

af41—AF class 4, low drop probability (100010)

af42—AF class 4, medium drop probability (100100)

af43—AF class 4, high drop probability (100110)

cs1—Class-selector (CS) 1, precedence 1 (001000)

cs2—CS2, precedence 2 (010000)

cs3—CS3, precedence 3 (011000)

cs4—CS4, precedence 4 (100000)

cs5—CS5, precedence 5 (101000)

cs6—CS6, precedence 6 (110000)

cs7—CS7, precedence 7 (111000)

default—Default DSCP value (000000)

ef—Expedited Forwarding (101110)

flow-label flow-label-value

(Optional) Specifies that the rule matches only IPv6 packets whose Flow Label header field has the value specified by the flow-label-value argument. The flow-label-value argument can be an integer from 0 to 1048575.

fragments

(Optional) Specifies that the rule matches noninitial fragmented packets only. The device considers noninitial fragmented packets to be packets with a fragment extension header that contains a fragment offset that is not equal to zero. You cannot specify this keyword in the same rule that you specify Layer 4 options, such as a TCP port number, because the information that the devices requires to evaluate those options is contained only in initial fragments.


Command Default

None

Command Modes

IPv6 ACL configuration

Command History

Release
Modification

6.0(2)N1(1)

This command was introduced.


Usage Guidelines

A newly created IPv6 ACL contains no rules.

When the device applies an IPv6 ACL to a packet, it evaluates the packet with every rule in the ACL. The device enforces the first rule whose conditions are satisfied by the packet. When the conditions of more than one rule are satisfied, the device enforces the rule with the lowest sequence number.

Source and Destination

You can specify the source and destination arguments in one of several ways. In each rule, the method you use to specify one of these arguments does not affect how you specify the other. When you configure a rule, use the following methods to specify the source and destination arguments:

Address and variable-length subnet mask—You can use an IPv6 address followed by a variable-length subnet mask (VLSM) to specify a host or a network as a source or destination. The syntax is as follows:

IPv6-address/prefix-len
 
   

This example shows how to specify the source argument with the IPv6 address and VLSM for the 2001:0db8:85a3:: network:

switch(config-acl)# deny icmp 2001:0db8:85a3::/48 any
 
   

Host address—You can use the host keyword and an IPv6 address to specify a host as a source or destination. The syntax is as follows:

host IPv6-address
 
   

This syntax is equivalent to IPv6-address/128.

This example shows how to specify the source argument with the host keyword and the 2001:0db8:85a3:08d3:1319:8a2e:0370:7344 IPv6 address:

switch(config-acl)# deny icmp host 2001:0db8:85a3:08d3:1319:8a2e:0370:7344 any
 
   

Any address—You can use the any keyword to specify that a source or destination is any IPv6 address. For examples of the use of the any keyword, see the examples in this section. Each example shows how to specify a source or destination by using the any keyword.

ICMPv6 Message Types

The icmp-message argument can be the ICMPv6 message number, which is an integer from 0 to 255. It can also be one of the following keywords:

beyond-scope—Destination beyond scope

destination-unreachable—Destination address is unreachable

echo-reply—Echo reply

echo-request—Echo request (ping)

header—Parameter header problems

hop-limit—Hop limit exceeded in transit

mld-query—Multicast Listener Discovery Query

mld-reduction—Multicast Listener Discovery Reduction

mld-report—Multicast Listener Discovery Report

nd-na—Neighbor discovery neighbor advertisements

nd-ns—Neighbor discovery neighbor solicitations

next-header—Parameter next header problems

no-admin—Administration prohibited destination

no-route—No route to destination

packet-too-big—Packet too big

parameter-option—Parameter option problems

parameter-problem—All parameter problems

port-unreachable—Port unreachable

reassembly-timeout—Reassembly timeout

redirect—Neighbor redirect

renum-command—Router renumbering command

renum-result—Router renumbering result

renum-seq-number—Router renumbering sequence number reset

router-advertisement—Neighbor discovery router advertisements

router-renumbering—All router renumbering

router-solicitation—Neighbor discovery router solicitations

time-exceeded—All time exceeded messages

unreachable—All unreachable

Examples

This example shows how to configure an IPv6 ACL named acl-lab13-ipv6 with rules denying all ICMP traffic from the 2001:0db8:85a3:: and 2001:0db8:69f2:: networks to the 2001:0db8:be03:2112:: network:

switch# configure terminal 
switch(config)# ipv6 access-list acl-lab13-ipv6 
switch(config-ipv6-acl)# deny icmp 2001:0db8:85a3::/48 2001:0db8:be03:2112::/64
switch(config-ipv6-acl)# deny icmp2001:0db8:69f2::/48 2001:0db8:be03:2112::/64
 
   

Related Commands

Command
Description

ipv6 access-list

Configures an IPv6 ACL.

permit (IPv6)

Configures a permit rule in an IPv6 ACL.

remark

Configures a remark in an ACL.

time-range

Configures a time range.


deny ipv6 (IPv6)

To create an access control list (ACL) rule that denies IPv6 traffic matching its conditions, use the deny command. To remove a rule, use the no form of this command.

[sequence-number] deny ipv6 source destination [dscp dscp | fragments]

no deny ipv6 source destination [dscp dscp | flow-label flow-label-value | fragments]

no sequence-number

Syntax Description

sequence-number

(Optional) Sequence number of the deny command, which causes the device to insert the command in that numbered position in the access list. Sequence numbers maintain the order of rules within an ACL.

A sequence number can be any integer between 1 and 4294967295.

By default, the first rule in an ACL has a sequence number of 10.

If you do not specify a sequence number, the device adds the rule to the end of the ACL and assigns a sequence number that is 10 greater than the sequence number of the preceding rule.

Use the resequence command to reassign sequence numbers to rules.

source

Source IPv6 addresses that the rule matches. For details about the methods that you can use to specify this argument, see the "Source and Destination" section in the "Usage Guidelines" section.

destination

Destination IPv6 addresses that the rule matches. For details about the methods that you can use to specify this argument, see the "Source and Destination" section in the "Usage Guidelines" section.

dscp dscp

(Optional) Specifies that the rule matches only packets with the specified 6-bit differentiated services value in the DSCP field of the IPv6 header. The dscp argument can be one of the following numbers or keywords:

0-63—The decimal equivalent of the 6 bits of the DSCP field. For example, if you specify 10, the rule matches only packets that have the following bits in the DSCP field: 001010.

af11—Assured Forwarding (AF) class 1, low drop probability (001010)

af12—AF class 1, medium drop probability (001100)

af13—AF class 1, high drop probability (001110)

af21—AF class 2, low drop probability (010010)

af22—AF class 2, medium drop probability (010100)

af23—AF class 2, high drop probability (010110)

af31—AF class 3, low drop probability (011010)

af32—AF class 3, medium drop probability (011100)

af33—AF class 3, high drop probability (011110)

af41—AF class 4, low drop probability (100010)

af42—AF class 4, medium drop probability (100100)

af43—AF class 4, high drop probability (100110)

cs1—Class-selector (CS) 1, precedence 1 (001000)

cs2—CS2, precedence 2 (010000)

cs3—CS3, precedence 3 (011000)

cs4—CS4, precedence 4 (100000)

cs5—CS5, precedence 5 (101000)

cs6—CS6, precedence 6 (110000)

cs7—CS7, precedence 7 (111000)

default—Default DSCP value (000000)

ef—Expedited Forwarding (101110)

fragments

(Optional) Specifies that the rule matches noninitial fragmented packets only. The device considers noninitial fragmented packets to be packets with a fragment extension header that contains a fragment offset that is not equal to zero. You cannot specify this keyword in the same rule that you specify Layer 4 options, such as a TCP port number, because the information that the devices requires to evaluate those options is contained only in initial fragments.


Command Default

None

Command Modes

IPv6 ACL configuration

Command History

Release
Modification

6.0(2)N1(1)

This command was introduced.


Usage Guidelines

A newly created IPv6 ACL contains no rules.

When the device applies an IPv6 ACL to a packet, it evaluates the packet with every rule in the ACL. The device enforces the first rule whose conditions are satisfied by the packet. When the conditions of more than one rule are satisfied, the device enforces the rule with the lowest sequence number.

Source and Destination

You can specify the source and destination arguments in one of several ways. In each rule, the method you use to specify one of these arguments does not affect how you specify the other. When you configure a rule, use the following methods to specify the source and destination arguments:

Address and variable-length subnet mask—You can use an IPv6 address followed by a variable-length subnet mask (VLSM) to specify a host or a network as a source or destination. The syntax is as follows:

IPv6-address/prefix-len
 
   

This example shows how to specify the source argument with the IPv6 address and VLSM for the 2001:0db8:85a3:: network:

switch(config-acl)# deny ipv6 2001:0db8:85a3::/48 any
 
   

Host address—You can use the host keyword and an IPv6 address to specify a host as a source or destination. The syntax is as follows:

host IPv6-address
 
   

This syntax is equivalent to IPv6-address/128.

This example shows how to specify the source argument with the host keyword and the 2001:0db8:85a3:08d3:1319:8a2e:0370:7344 IPv6 address:

switch(config-acl)# deny ipv6 host 2001:0db8:85a3:08d3:1319:8a2e:0370:7344 any
 
   

Any address—You can use the any keyword to specify that a source or destination is any IPv6 address. For examples of the use of the any keyword, see the examples in this section. Each example shows how to specify a source or destination by using the any keyword.

Examples

This example shows how to configure an IPv6 ACL named acl-lab13-ipv6 with rules denying all IPv6 traffic from the 2001:0db8:85a3:: and 2001:0db8:69f2:: networks to the 2001:0db8:be03:2112:: network:

switch# configure terminal 
switch(config)# ipv6 access-list acl-lab13-ipv6 
switch(config-ipv6-acl)# deny ipv6 2001:0db8:85a3::/48 2001:0db8:be03:2112::/64
switch(config-ipv6-acl)# deny ipv6 2001:0db8:69f2::/48 2001:0db8:be03:2112::/64
 
   

Related Commands

Command
Description

ipv6 access-list

Configures an IPv6 ACL.

permit (IPv6)

Configures a permit rule in an IPv6 ACL.

remark

Configures a remark in an ACL.

time-range

Configures a time range.


deny sctp (IPv6)

To create an access control list (ACL) rule that denies SCTP IPv6 traffic matching its conditions, use the deny command. To remove a rule, use the no form of this command.

[sequence-number] deny sctp source [operator port [port] | portgroup portgroup] destination [operator port [port] | portgroup portgroup] [dscp dscp | flow-label flow-label-value | fragments]

no deny sctp source [operator port [port] | portgroup portgroup] destination [operator port [port] | portgroup portgroup] [dscp dscp | flow-label flow-label-value | fragments | log ]

no sequence-number

Syntax Description

sequence-number

(Optional) Sequence number of the deny command, which causes the device to insert the command in that numbered position in the access list. Sequence numbers maintain the order of rules within an ACL.

A sequence number can be any integer between 1 and 4294967295.

By default, the first rule in an ACL has a sequence number of 10.

If you do not specify a sequence number, the device adds the rule to the end of the ACL and assigns a sequence number that is 10 greater than the sequence number of the preceding rule.

Use the resequence command to reassign sequence numbers to rules.

source

Source IPv6 addresses that the rule matches. For details about the methods that you can use to specify this argument, see the "Source and Destination" section in the "Usage Guidelines" section.

destination

Destination IPv6 addresses that the rule matches. For details about the methods that you can use to specify this argument, see the "Source and Destination" section in the "Usage Guidelines" section.

operator port [port]

(Optional) Rule matches only packets that are from a source port or sent to a destination port that satisfies the conditions of the operator and port arguments. Whether these arguments apply to a source port or a destination port depends upon whether you specify them after the source argument or after the destination argument.

The port argument can be the name or the number of a TCP or UDP port. Valid numbers are integers from 0 to 65535. For listings of valid port names, see "TCP Port Names" and "UDP Port Names" in the "Usage Guidelines" section.

A second port argument is required only when the operator argument is a range.

The operator argument must be one of the following keywords:

eq—Matches only if the port in the packet is equal to the port argument.

gt—Matches only if the port in the packet is greater than the port argument.

lt—Matches only if the port in the packet is less than the port argument.

neq—Matches only if the port in the packet is not equal to the port argument.

range—Requires two port arguments and matches only if the port in the packet is equal to or greater than the first port argument and equal to or less than the second port argument.

portgroup portgroup

(Optional) Specifies that the rule matches only packets that are from a source port or to a destination port that is a member of the IP port-group object specified by the portgroup argument. Whether the port-group object applies to a source port or a destination port depends upon whether you specify it after the source argument or after the destination argument.

Use the object-group ip port command to create and change IP port-group objects.

dscp dscp

(Optional) Specifies that the rule matches only packets with the specified 6-bit differentiated services value in the DSCP field of the IPv6 header. The dscp argument can be one of the following numbers or keywords:

0-63—The decimal equivalent of the 6 bits of the DSCP field. For example, if you specify 10, the rule matches only packets that have the following bits in the DSCP field: 001010.

af11—Assured Forwarding (AF) class 1, low drop probability (001010)

af12—AF class 1, medium drop probability (001100)

af13—AF class 1, high drop probability (001110)

af21—AF class 2, low drop probability (010010)

af22—AF class 2, medium drop probability (010100)

af23—AF class 2, high drop probability (010110)

af31—AF class 3, low drop probability (011010)

af32—AF class 3, medium drop probability (011100)

af33—AF class 3, high drop probability (011110)

af41—AF class 4, low drop probability (100010)

af42—AF class 4, medium drop probability (100100)

af43—AF class 4, high drop probability (100110)

cs1—Class-selector (CS) 1, precedence 1 (001000)

cs2—CS2, precedence 2 (010000)

cs3—CS3, precedence 3 (011000)

cs4—CS4, precedence 4 (100000)

cs5—CS5, precedence 5 (101000)

cs6—CS6, precedence 6 (110000)

cs7—CS7, precedence 7 (111000)

default—Default DSCP value (000000)

ef—Expedited Forwarding (101110)

flow-label flow-label-value

(Optional) Specifies that the rule matches only IPv6 packets whose Flow Label header field has the value specified by the flow-label-value argument. The flow-label-value argument can be an integer from 0 to 1048575.

fragments

(Optional) Specifies that the rule matches noninitial fragmented packets only. The device considers noninitial fragmented packets to be packets with a fragment extension header that contains a fragment offset that is not equal to zero. You cannot specify this keyword in the same rule that you specify Layer 4 options, such as a TCP port number, because the information that the devices requires to evaluate those options is contained only in initial fragments.


Command Default

None

Command Modes

IPv6 ACL configuration

Command History

Release
Modification

6.0(2)N1(1)

This command was introduced.


Usage Guidelines

A newly created IPv6 ACL contains no rules.

When the device applies an IPv6 ACL to a packet, it evaluates the packet with every rule in the ACL. The device enforces the first rule whose conditions are satisfied by the packet. When the conditions of more than one rule are satisfied, the device enforces the rule with the lowest sequence number.

Source and Destination

You can specify the source and destination arguments in one of several ways. In each rule, the method you use to specify one of these arguments does not affect how you specify the other. When you configure a rule, use the following methods to specify the source and destination arguments:

Address and variable-length subnet mask—You can use an IPv6 address followed by a variable-length subnet mask (VLSM) to specify a host or a network as a source or destination. The syntax is as follows:

IPv6-address/prefix-len
 
   

This example shows how to specify the source argument with the IPv6 address and VLSM for the 2001:0db8:85a3:: network:

switch(config-acl)# deny sctp 2001:0db8:85a3::/48 any
 
   

Host address—You can use the host keyword and an IPv6 address to specify a host as a source or destination. The syntax is as follows:

host IPv6-address
 
   

This syntax is equivalent to IPv6-address/128.

This example shows how to specify the source argument with the host keyword and the 2001:0db8:85a3:08d3:1319:8a2e:0370:7344 IPv6 address:

switch(config-acl)# deny sctp host 2001:0db8:85a3:08d3:1319:8a2e:0370:7344 any
 
   

Any address—You can use the any keyword to specify that a source or destination is any IPv6 address. For examples of the use of the any keyword, see the examples in this section. Each example shows how to specify a source or destination by using the any keyword.

Examples

This example shows how to configure an IPv6 ACL named acl-lab13-ipv6 with rules denying all SCTP traffic from the 2001:0db8:85a3:: and 2001:0db8:69f2:: networks to the 2001:0db8:be03:2112:: network:

switch# configure terminal 
switch(config)# ipv6 access-list acl-lab13-ipv6 
switch(config-ipv6-acl)# deny sctp 2001:0db8:85a3::/48 2001:0db8:be03:2112::/64
switch(config-ipv6-acl)# deny sctp 2001:0db8:69f2::/48 2001:0db8:be03:2112::/64
 
   

Related Commands

Command
Description

ipv6 access-list

Configures an IPv6 ACL.

permit (IPv6)

Configures a permit rule in an IPv6 ACL.

remark

Configures a remark in an ACL.

time-range

Configures a time range.


deny tcp (IPv6)

To create an access control list (ACL) rule that denies TCP IPv6 traffic matching its conditions, use the deny command. To remove a rule, use the no form of this command.

General Syntax

[sequence-number] deny tcp source [operator port [port] | portgroup portgroup] destination [operator port [port] | portgroup portgroup] [dscp dscp | flow-label flow-label-value | fragments | flags | established]

no deny tcp source [operator port [port] | portgroup portgroup] destination [operator port [port] | portgroup portgroup] [dscp dscp | flow-label flow-label-value | fragments | flags | established]

no sequence-number

Syntax Description

sequence-number

(Optional) Sequence number of the deny command, which causes the device to insert the command in that numbered position in the access list. Sequence numbers maintain the order of rules within an ACL.

A sequence number can be any integer between 1 and 4294967295.

By default, the first rule in an ACL has a sequence number of 10.

If you do not specify a sequence number, the device adds the rule to the end of the ACL and assigns a sequence number that is 10 greater than the sequence number of the preceding rule.

Use the resequence command to reassign sequence numbers to rules.

source

Source IPv6 addresses that the rule matches. For details about the methods that you can use to specify this argument, see the "Source and Destination" section in the "Usage Guidelines" section.

destination

Destination IPv6 addresses that the rule matches. For details about the methods that you can use to specify this argument, see the "Source and Destination" section in the "Usage Guidelines" section.

operator port [port]

(Optional) Rule matches only packets that are from a source port or sent to a destination port that satisfies the conditions of the operator and port arguments. Whether these arguments apply to a source port or a destination port depends upon whether you specify them after the source argument or after the destination argument.

The port argument can be the name or the number of a TCP port. Valid numbers are integers from 0 to 65535. For listings of valid port names, see the "TCP Port Names" section in the "Usage Guidelines" section.

A second port argument is required only when the operator argument is a range.

The operator argument must be one of the following keywords:

eq—Matches only if the port in the packet is equal to the port argument.

gt—Matches only if the port in the packet is greater than the port argument.

lt—Matches only if the port in the packet is less than the port argument.

neq—Matches only if the port in the packet is not equal to the port argument.

range—Requires two port arguments and matches only if the port in the packet is equal to or greater than the first port argument and equal to or less than the second port argument.

portgroup portgroup

(Optional) Specifies that the rule matches only packets that are from a source port or to a destination port that is a member of the IP port-group object specified by the portgroup argument. Whether the port-group object applies to a source port or a destination port depends upon whether you specify it after the source argument or after the destination argument.

Use the object-group ip port command to create and change IP port-group objects.

dscp dscp

(Optional) Specifies that the rule matches only packets with the specified 6-bit differentiated services value in the DSCP field of the IPv6 header. The dscp argument can be one of the following numbers or keywords:

0-63—The decimal equivalent of the 6 bits of the DSCP field. For example, if you specify 10, the rule matches only packets that have the following bits in the DSCP field: 001010.

af11—Assured Forwarding (AF) class 1, low drop probability (001010)

af12—AF class 1, medium drop probability (001100)

af13—AF class 1, high drop probability (001110)

af21—AF class 2, low drop probability (010010)

af22—AF class 2, medium drop probability (010100)

af23—AF class 2, high drop probability (010110)

af31—AF class 3, low drop probability (011010)

af32—AF class 3, medium drop probability (011100)

af33—AF class 3, high drop probability (011110)

af41—AF class 4, low drop probability (100010)

af42—AF class 4, medium drop probability (100100)

af43—AF class 4, high drop probability (100110)

cs1—Class-selector (CS) 1, precedence 1 (001000)

cs2—CS2, precedence 2 (010000)

cs3—CS3, precedence 3 (011000)

cs4—CS4, precedence 4 (100000)

cs5—CS5, precedence 5 (101000)

cs6—CS6, precedence 6 (110000)

cs7—CS7, precedence 7 (111000)

default—Default DSCP value (000000)

ef—Expedited Forwarding (101110)

flow-label flow-label-value

(Optional) Specifies that the rule matches only IPv6 packets whose Flow Label header field has the value specified by the flow-label-value argument. The flow-label-value argument can be an integer from 0 to 1048575.

fragments

(Optional) Specifies that the rule matches noninitial fragmented packets only. The device considers noninitial fragmented packets to be packets with a fragment extension header that contains a fragment offset that is not equal to zero. You cannot specify this keyword in the same rule that you specify Layer 4 options, such as a TCP port number, because the information that the devices requires to evaluate those options is contained only in initial fragments.

flags

(Optional) Rule matches only packets that have specific TCP control bit flags set. The value of the flags argument must be one or more of the following keywords:

ack

fin

psh

rst

syn

urg

established

(Optional) Specifies that the rule matches only packets that belong to an established TCP connection. The device considers TCP packets with the ACK or RST bits set to belong to an established connection.


Command Default

None

Command Modes

IPv6 ACL configuration

Command History

Release
Modification

6.0(2)N1(1)

This command was introduced.


Usage Guidelines

A newly created IPv6 ACL contains no rules.

When the device applies an IPv6 ACL to a packet, it evaluates the packet with every rule in the ACL. The device enforces the first rule whose conditions are satisfied by the packet. When the conditions of more than one rule are satisfied, the device enforces the rule with the lowest sequence number.

Source and Destination

You can specify the source and destination arguments in one of several ways. In each rule, the method you use to specify one of these arguments does not affect how you specify the other. When you configure a rule, use the following methods to specify the source and destination arguments:

Address and variable-length subnet mask—You can use an IPv6 address followed by a variable-length subnet mask (VLSM) to specify a host or a network as a source or destination. The syntax is as follows:

IPv6-address/prefix-len
 
   

This example shows how to specify the source argument with the IPv6 address and VLSM for the 2001:0db8:85a3:: network:

switch(config-acl)# deny tcp 2001:0db8:85a3::/48 any
 
   

Host address—You can use the host keyword and an IPv6 address to specify a host as a source or destination. The syntax is as follows:

host IPv6-address
 
   

This syntax is equivalent to IPv6-address/128.

This example shows how to specify the source argument with the host keyword and the 2001:0db8:85a3:08d3:1319:8a2e:0370:7344 IPv6 address:

switch(config-acl)# deny tcp host 2001:0db8:85a3:08d3:1319:8a2e:0370:7344 any
 
   

Any address—You can use the any keyword to specify that a source or destination is any IPv6 address. For examples of the use of the any keyword, see the examples in this section. Each example shows how to specify a source or destination by using the any keyword.

TCP Port Names

When you specify the protocol argument as tcp, the port argument can be a TCP port number, which is an integer from 0 to 65535. It can also be one of the following keywords:

bgp—Border Gateway Protocol (179)

chargen—Character generator (19)

cmd—Remote commands (rcmd, 514)

daytime—Daytime (13)

discard—Discard (9)

domain—Domain Name Service (53)

drip—Dynamic Routing Information Protocol (3949)

echo—Echo (7)

exec—Exec (rsh, 512)

finger—Finger (79)

ftp—File Transfer Protocol (21)

ftp-data—FTP data connections (2)

gopher—Gopher (7)

hostname—NIC hostname server (11)

ident—Ident Protocol (113)

irc—Internet Relay Chat (194)

klogin—Kerberos login (543)

kshell—Kerberos shell (544)

login—Login (rlogin, 513)

lpd—Printer service (515)

nntp—Network News Transport Protocol (119)

pim-auto-rp—PIM Auto-RP (496)

pop2—Post Office Protocol v2 (19)

pop3—Post Office Protocol v3 (11)

smtp—Simple Mail Transport Protocol (25)

sunrpc—Sun Remote Procedure Call (111)

tacacs—TAC Access Control System (49)

talk—Talk (517)

telnet—Telnet (23)

time—Time (37)

uucp—Unix-to-Unix Copy Program (54)

whois—WHOIS/NICNAME (43)

www—World Wide Web (HTTP, 8)

Examples

This example shows how to configure an IPv6 ACL named acl-lab13-ipv6 with rules denying all TCP traffic from the 2001:0db8:85a3:: and 2001:0db8:69f2:: networks to the 2001:0db8:be03:2112:: network:

switch# configure terminal 
switch(config)# ipv6 access-list acl-lab13-ipv6 
switch(config-ipv6-acl)# deny tcp 2001:0db8:85a3::/48 2001:0db8:be03:2112::/64
switch(config-ipv6-acl)# deny tcp 2001:0db8:69f2::/48 2001:0db8:be03:2112::/64
 
   

Related Commands

Command
Description

ipv6 access-list

Configures an IPv6 ACL.

permit (IPv6)

Configures a permit rule in an IPv6 ACL.

remark

Configures a remark in an ACL.

time-range

Configures a time range.


deny udp (IPv6)

To create an access control list (ACL) rule that denies UDP IPv6 traffic matching its conditions, use the deny command. To remove a rule, use the no form of this command.To create an IPv6 ACL rule that denies traffic matching its conditions, use the deny command. To remove a rule, use the no form of this command.

General Syntax

[sequence-number] deny udp source [operator port [port] | portgroup portgroup] destination [operator port [port] | portgroup portgroup] [dscp dscp | flow-label flow-label-value | fragments]

no deny udp source [operator port [port] | portgroup portgroup] destination [operator port [port] | portgroup portgroup] [dscp dscp | flow-label flow-label-value | fragments]

no sequence-number

Syntax Description

sequence-number

(Optional) Sequence number of the deny command, which causes the device to insert the command in that numbered position in the access list. Sequence numbers maintain the order of rules within an ACL.

A sequence number can be any integer between 1 and 4294967295.

By default, the first rule in an ACL has a sequence number of 10.

If you do not specify a sequence number, the device adds the rule to the end of the ACL and assigns a sequence number that is 10 greater than the sequence number of the preceding rule.

Use the resequence command to reassign sequence numbers to rules.

source

Source IPv6 addresses that the rule matches. For details about the methods that you can use to specify this argument, see the "Source and Destination" section in the "Usage Guidelines" section.

destination

Destination IPv6 addresses that the rule matches. For details about the methods that you can use to specify this argument, see the "Source and Destination" section in the "Usage Guidelines" section.

operator port [port]

(Optional) Rule matches only packets that are from a source port or sent to a destination port that satisfies the conditions of the operator and port arguments. Whether these arguments apply to a source port or a destination port depends upon whether you specify them after the source argument or after the destination argument.

The port argument can be the name or the number of a UDP port. Valid numbers are integers from 0 to 65535. For listings of valid port names, see the "UDP Port Names" section in the "Usage Guidelines" section.

A second port argument is required only when the operator argument is a range.

The operator argument must be one of the following keywords:

eq—Matches only if the port in the packet is equal to the port argument.

gt—Matches only if the port in the packet is greater than the port argument.

lt—Matches only if the port in the packet is less than the port argument.

neq—Matches only if the port in the packet is not equal to the port argument.

range—Requires two port arguments and matches only if the port in the packet is equal to or greater than the first port argument and equal to or less than the second port argument.

portgroup portgroup

(Optional) Specifies that the rule matches only packets that are from a source port or to a destination port that is a member of the IP port-group object specified by the portgroup argument. Whether the port-group object applies to a source port or a destination port depends upon whether you specify it after the source argument or after the destination argument.

Use the object-group ip port command to create and change IP port-group objects.

dscp dscp

(Optional) Specifies that the rule matches only packets with the specified 6-bit differentiated services value in the DSCP field of the IPv6 header. The dscp argument can be one of the following numbers or keywords:

0-63—The decimal equivalent of the 6 bits of the DSCP field. For example, if you specify 10, the rule matches only packets that have the following bits in the DSCP field: 001010.

af11—Assured Forwarding (AF) class 1, low drop probability (001010)

af12—AF class 1, medium drop probability (001100)

af13—AF class 1, high drop probability (001110)

af21—AF class 2, low drop probability (010010)

af22—AF class 2, medium drop probability (010100)

af23—AF class 2, high drop probability (010110)

af31—AF class 3, low drop probability (011010)

af32—AF class 3, medium drop probability (011100)

af33—AF class 3, high drop probability (011110)

af41—AF class 4, low drop probability (100010)

af42—AF class 4, medium drop probability (100100)

af43—AF class 4, high drop probability (100110)

cs1—Class-selector (CS) 1, precedence 1 (001000)

cs2—CS2, precedence 2 (010000)

cs3—CS3, precedence 3 (011000)

cs4—CS4, precedence 4 (100000)

cs5—CS5, precedence 5 (101000)

cs6—CS6, precedence 6 (110000)

cs7—CS7, precedence 7 (111000)

default—Default DSCP value (000000)

ef—Expedited Forwarding (101110)

flow-label flow-label-value

(Optional) Specifies that the rule matches only IPv6 packets whose Flow Label header field has the value specified by the flow-label-value argument. The flow-label-value argument can be an integer from 0 to 1048575.

fragments

(Optional) Specifies that the rule matches noninitial fragmented packets only. The device considers noninitial fragmented packets to be packets with a fragment extension header that contains a fragment offset that is not equal to zero. You cannot specify this keyword in the same rule that you specify Layer 4 options, such as a TCP port number, because the information that the devices requires to evaluate those options is contained only in initial fragments.


Command Default

None

Command Modes

IPv6 ACL configuration

Command History

Release
Modification

6.0(2)N1(1)

This command was introduced.


Usage Guidelines

A newly created IPv6 ACL contains no rules.

When the device applies an IPv6 ACL to a packet, it evaluates the packet with every rule in the ACL. The device enforces the first rule whose conditions are satisfied by the packet. When the conditions of more than one rule are satisfied, the device enforces the rule with the lowest sequence number.

Source and Destination

You can specify the source and destination arguments in one of several ways. In each rule, the method you use to specify one of these arguments does not affect how you specify the other. When you configure a rule, use the following methods to specify the source and destination arguments:

Address and variable-length subnet mask—You can use an IPv6 address followed by a variable-length subnet mask (VLSM) to specify a host or a network as a source or destination. The syntax is as follows:

IPv6-address/prefix-len
 
   

This example shows how to specify the source argument with the IPv6 address and VLSM for the 2001:0db8:85a3:: network:

switch(config-acl)# deny udp 2001:0db8:85a3::/48 any
 
   

Host address—You can use the host keyword and an IPv6 address to specify a host as a source or destination. The syntax is as follows:

host IPv6-address
 
   

This syntax is equivalent to IPv6-address/128.

This example shows how to specify the source argument with the host keyword and the 2001:0db8:85a3:08d3:1319:8a2e:0370:7344 IPv6 address:

switch(config-acl)# deny udp host 2001:0db8:85a3:08d3:1319:8a2e:0370:7344 any
 
   

Any address—You can use the any keyword to specify that a source or destination is any IPv6 address. For examples of the use of the any keyword, see the examples in this section. Each example shows how to specify a source or destination by using the any keyword.

UDP Port Names

When you specify the protocol argument as udp, the port argument can be a UDP port number, which is an integer from 0 to 65535. It can also be one of the following keywords:

biff—Biff (mail notification, comsat, 512)

bootpc—Bootstrap Protocol (BOOTP) client (68)

bootps—Bootstrap Protocol (BOOTP) server (67)

discard—Discard (9)

dnsix—DNSIX security protocol auditing (195)

domain—Domain Name Service (DNS, 53)

echo—Echo (7)

isakmp—Internet Security Association and Key Management Protocol (5)

mobile-ip—Mobile IP registration (434)

nameserver—IEN116 name service (obsolete, 42)

netbios-dgm—NetBIOS datagram service (138)

netbios-ns—NetBIOS name service (137)

netbios-ss—NetBIOS session service (139)

non500-isakmp—Internet Security Association and Key Management Protocol (45)

ntp—Network Time Protocol (123)

pim-auto-rp—PIM Auto-RP (496)

rip—Routing Information Protocol (router, in.routed, 52)

snmp—Simple Network Management Protocol (161)

snmptrap—SNMP Traps (162)

sunrpc—Sun Remote Procedure Call (111)

syslog—System Logger (514)

tacacs—TAC Access Control System (49)

talk—Talk (517)

tftp—Trivial File Transfer Protocol (69)

time—Time (37)

who—Who service (rwho, 513)

xdmcp—X Display Manager Control Protocol (177)

Examples

This example shows how to configure an IPv6 ACL named acl-lab13-ipv6 with rules denying all UDP traffic from the 2001:0db8:85a3:: and 2001:0db8:69f2:: networks to the 2001:0db8:be03:2112:: network:

switch# configure terminal 
switch(config)# ipv6 access-list acl-lab13-ipv6 
switch(config-ipv6-acl)# deny udp 2001:0db8:85a3::/48 2001:0db8:be03:2112::/64
switch(config-ipv6-acl)# deny udp 2001:0db8:69f2::/48 2001:0db8:be03:2112::/64
 
   

Related Commands

Command
Description

ipv6 access-list

Configures an IPv6 ACL.

permit (IPv6)

Configures a permit rule in an IPv6 ACL.

remark

Configures a remark in an ACL.

time-range

Configures a time range.


deny (MAC)

To create a Media Access Control (MAC) access control list (ACL)+ rule that denies traffic matching its conditions, use the deny command. To remove a rule, use the no form of this command.

[sequence-number] deny source destination [protocol] [cos cos-value] [vlan vlan-id]

no deny source destination [protocol] [cos cos-value] [vlan vlan-id]

no sequence-number

Syntax Description

sequence-number

(Optional) Sequence number of the deny command, which causes the switch to insert the command in that numbered position in the access list. Sequence numbers maintain the order of rules within an ACL.

A sequence number can be any integer between 1 and 4294967295.

By default, the first rule in an ACL has a sequence number of 10.

If you do not specify a sequence number, the switch adds the rule to the end of the ACL and assigns to it a sequence number that is 10 greater than the sequence number of the preceding rule.

Use the resequence command to reassign sequence numbers to rules.

source

Source MAC addresses that the rule matches. For details about the methods that you can use to specify this argument, see "Source and Destination" in the "Usage Guidelines" section.

destination

Destination MAC addresses that the rule matches. For details about the methods that you can use to specify this argument, see "Source and Destination" in the "Usage Guidelines" section.

protocol

(Optional) Protocol number that the rule matches. Valid protocol numbers are 0x0 to 0xffff. For listings of valid protocol names, see "MAC Protocols" in the "Usage Guidelines" section.

cos cos-value

(Optional) Specifies that the rule matches only packets whose IEEE 802.1Q header contains the class of service (CoS) value given in the cos-value argument. The cos-value argument can be an integer from 0 to 7.

vlan vlan-id

(Optional) Specifies that the rule matches only packets whose IEEE 802.1Q header contains the VLAN ID given. The vlan-id argument can be an integer from 1 to 4094.


Command Default

A newly created MAC ACL contains no rules.

If you do not specify a sequence number, the switch assigns the rule a sequence number that is 10 greater than the last rule in the ACL.

Command Modes

MAC ACL configuration mode

Command History

Release
Modification

6.0(2)N1(1)

This command was introduced.


Usage Guidelines

When the switch applies a MAC ACL to a packet, it evaluates the packet with every rule in the ACL. The switch enforces the first rule whose conditions are satisfied by the packet. When the conditions of more than one rule are satisfied, the switch enforces the rule with the lowest sequence number.

Source and Destination

You can specify the source and destination arguments in one of two ways. In each rule, the method that you use to specify one of these arguments does not affect how you specify the other argument. When you configure a rule, use the following methods to specify the source and destination arguments:

Address and mask—You can use a MAC address followed by a mask to specify a single address or a group of addresses. The syntax is as follows:

MAC-address MAC-mask 
 
   

This example specifies the source argument with the MAC address 00c0.4f03.0a72:

switch(config-acl)# deny 00c0.4f03.0a72 0000.0000.0000 any 
 
   

This example specifies the destination argument with a MAC address for all hosts with a MAC vendor code of 00603e:

switch(config-acl)# deny any 0060.3e00.0000 0000.0000.0000 
 
   

Any address—You can use the any keyword to specify that a source or destination is any MAC address. For examples of the use of the any keyword, see the examples in this section. Each of the examples shows how to specify a source or destination by using the any keyword.

MAC Protocols

The protocol argument can be the MAC protocol number or a keyword. Protocol numbers are a four-byte hexadecimal number prefixed with 0x. Valid protocol numbers are from 0x0 to 0xffff. Valid keywords are the following:

aarp—Appletalk ARP (0x80f3)

appletalk—Appletalk (0x809b)

decnet-iv—DECnet Phase IV (0x6003)

diagnostic—DEC Diagnostic Protocol (0x6005)

etype-6000—EtherType 0x6000 (0x6000)

etype-8042—EtherType 0x8042 (0x8042)

ip—Internet Protocol v4 (0x0800)

lat—DEC LAT (0x6004)

lavc-sca—DEC LAVC, SCA (0x6007)

mop-console—DEC MOP Remote console (0x6002)

mop-dump—DEC MOP dump (0x6001)

vines-echo—VINES Echo (0x0baf)

Examples

This example shows how to configure a MAC ACL named mac-ip-filter with rules that permit any non-IPv4 traffic between two groups of MAC addresses:

switch(config)# mac access-list mac-ip-filter 
switch(config-mac-acl)# deny 00c0.4f00.0000 0000.00ff.ffff 0060.3e00.0000 0000.00ff.ffff 
ip 
switch(config-mac-acl)# permit any any 
 
   

Related Commands

Command
Description

mac access-list

Configures a MAC ACL.

permit (MAC)

Configures a deny rule in a MAC ACL.

remark

Configures a remark in an ACL.

show mac access-list

Displays all MAC ACLs or one MAC ACL.


description (user role)

To configure a description for a user role, use the description command. To revert to the default, use the no form of this command.

description text

no description

Syntax Description

text

Text string that describes the user role. The maximum length is 128 alphanumeric characters.


Command Default

None

Command Modes

User role configuration mode

Command History

Release
Modification

6.0(2)N1(1)

This command was introduced.


Usage Guidelines

You can include blank spaces in the user role description text.

Examples

This example shows how to configure the description for a user role:

switch(config)# role name MyRole 
switch(config-role)# description User role for my user account. 
 
   

This example shows how to remove the description from a user role:

switch(config)# role name MyRole 
switch(config-role)# no description 
 
   

Related Commands

Command
Description

show role

Displays information about the user role configuration.