Table Of Contents

Transparent Bridging Commands

reset address

reset filter

reset pattern

reset type

set address

set age

set bridging

set filter

set learn

set mode

set passthru

set pattern

set type

set unicastfilter

show address

show ethernet

show filter

show pattern

show type

Transparent Bridging Commands

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This chapter describes commands such as filtering and address learning used to configure transparent bridging.

reset address

To delete one or all of the manually entered Ethernet addresses stored in the filtering table with the set address command, use the reset address command.

REset ADdress address | ALl

Syntax Description

address	Deletes an Ethernet address that has been previously entered with the set address command. Must be entered as 12 contiguous hexadecimal characters (no spaces).
ALl	Deletes all Ethernet addresses in the profile that have been entered with the set address command.

Command Mode

Profile mode

Example

The following example deletes one static address from the profile 2503:

Host:2503> reset address 00000c00755d

Related Command

set address

reset filter

To delete one or all user-defined bridge filters, use the reset filter command.

REset [id] FIlter = [ALl]

Syntax Description

id	Deletes filters based on the identification number assigned to the filter when it is created with the set filter command.
ALl	Deletes all filters.

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Note   Use the show filter command to determine filter ID numbers.

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Default

None

Command Mode

System or profile mode

Examples

The following example deletes the filter with the identification number 4 from profile 2503:

Host:2503> reset 4 filter

The following example deletes all filters from profile 2503:

Host:2503> reset filter all

Related Commands

set filter
show filter

reset pattern

To delete one or all bridge filtering patterns, use the reset pattern command.

REset [patternname] PATtern = [ALl]

Syntax Description

patternname	Deletes a specific pattern based on the pattern name assigned with the set pattern command.
PATtern ALl	Deletes all patterns.

Default

None

Command Mode

System mode

Examples

The following example deletes a pattern called arp from profile 2503:

Host:2503> reset arp pattern

The following example deletes all patterns from profile 2503:

Host:2503> reset pattern all

Related Commands

set pattern

show pattern

reset type

To delete one or all bridge type filters, use the reset type command.

REset TYpe = type | ALl

Syntax Description

type	Deletes a type filter based on the packet type defined with the set type command. Must be in the form of a four-digit hexadecimal number with no spaces.
ALl	Deletes all types of filters.

Default

None

Command Mode

System mode

Examples

The following example deletes a type filter based on packet type:

Host> reset type 0806

The following example deletes all type filters:

Host> reset type all

Related Command

set type

set address

To add an Ethernet address to a profile's static address table, use the set address command. This command applies only to bridging.

SEt ADdress = address

Syntax Description

address

Adds the specified Ethernet address to the profile's static address table. Must be entered as 12 contiguous hexadecimal characters (no spaces). The Ethernet address cannot exist on the same network as the router. Static addresses are associated with the profile's connection. Packets received from the LAN or ISDN line that contains a static address as a destination address will be forwarded to the connection of the profile containing that static address.

Default

No static addresses are configured.

Command Mode

Profile mode

Usage Guidelines

To delete an address entered with this command, use the reset address command. The Cisco Remote Office (RO) version routers can store up to 1500 Ethernet addresses in a combination of learned and static addresses. The Cisco Small Office Home Office (SOHO) version routers can store only four Ethernet addresses.

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Note   Static addresses are stored in nonvolatile RAM (NVRAM). When there is no more NVRAM available, a warning is displayed. A static address entered after this warning has been displayed is stored in RAM and lost when the router is powered down.

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Example

The following example adds a static Ethernet address to the profile 2503:

Host:2503> set address 00000c1235ff

Related Command

reset address

set age

To specify the maximum amount of time that a learned Ethernet address remains in the address table, use the set age command.

SEt AGe = seconds | OFf]

Syntax Description

seconds	The time in seconds that any inactive learned Ethernet address remains in the address table. Must be between 1 and 1,000,000. When the router receives a packet with a source address matching a learned address, the age for that address is reset to 0.
OFf	Learned Ethernet addresses remain in the address table indefinitely.

Default

Off

Command Mode

System mode

Example

The following example configures the router to delete learned Ethernet addresses after one hour of no activity from the address:

Host> set age 60 

set bridging

To determine what to do with packets that cannot be routed, use the set bridging command.

SEt BRidging ON | OFf

Syntax Description

ON	Packet will be bridged based on Media Access Control (MAC) address and any other filters currently active.
OFf	Drop packets.

Default

On

Command Mode

System mode

Example

The following example drops packets that cannot be routed:

Host> set bridging off

set filter

To create a user-defined bridge filter, use the set filter command.

SEt [id] FIlter [patternname] [BLock | ACcept] [DEmand | IGnore]

Syntax Description

id	The filter ID argument is assigned by the router and is not used to create a filter. It is used to modify existing filter configurations.
patternname	A pattern created with the set pattern command. Filters are composed of patterns. This argument can have up to eight pattern names. If you are using more than one pattern in a filter, all patterns must use the same (from) value in the set pattern command.
BLock	Prevents packets that match the filter from being forwarded to the connection.
ACcept	Allows only packets that match the filter to be forwarded to the connection.
DEmand	Packets that match the filter are counted in the threshold values that keep the ISDN line connected.
IGnore	Packets that match the filter are not counted in the threshold values that keep the ISDN line connected.

Default

No filters are configured.

Command Mode

System or profile mode

Usage Guidelines

Although multiple filters can be defined as accept, block, demand or ignore, the most recently defined filter determines which set of filters is used. When the packet comes in, it is evaluated by the most recent filter. If that filter blocks the packet, the packet is dropped, even if another filter would have accepted the packet.

Filters defined in system mode are used by all profiles. Filters defined in profile mode are used by that profile only. Filters apply to packets received from the connection associated with the profile in which the filters are defined.

To display filter IDs, use the show filter command.

Example

The following example configures a filter that will be used by all profiles:

Host> set filter arp demand

Related Commands

reset filter
set filter
set ip filter
show filter
show ip filter
set pattern

set learn

To enable or disable the Ethernet address learning function, use the set learn command.

SEt LEarn ON | OFf

Syntax Description

ON	Enables Ethernet address learning. Addresses are associated with a profile connection and are used for making bridge filtering decisions.
OFf	Disables Ethernet address learning. Only addresses entered with the set address command are used to make packet forwarding decisions.

Default

On (Enabled)

Command Mode

Profile mode

Usage Guidelines

This command applies only when bridging is enabled with the set bridging command.

Example

The following example enables Ethernet address learning on the profile 2503 connection:

Host:2503> set learn on

Related Commands

set address
set bridging
set mode

set mode

To configure packet forwarding for bridging, use the set mode command.

SEt [WAN | LAN] MOde = ANy | ONly

Syntax Description

WAN	Applies the configuration to packets received from the LAN and destined for the ISDN line.
LAN	Applies the configuration to packets received from the ISDN line and destined for the LAN.
ANy	Packets with unknown destination addresses are forwarded to all active connections.
ONly	Packets with unknown destination addresses are discarded.

Defaults

wan only
lan any

Command Mode

System mode

Usage Guidelines

Addresses are learned either by enabling learning with the set learn command or by entering them manually with the set address command.

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Note   Broadcast and multicast packets are always forwarded unless filters are configured to block them.

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Example

The following example configures the router to forward any packets with unknown destination addresses from the LAN to the ISDN line:

Host> set wan mode any

Related Commands

set address
set learn

set passthru

To configure packet bridging between ISDN connections, use the set passthru command.

SEt PASSThru ON | OFf

Syntax Description

ON	Enables individual remote routers to bridge to each other through the router.
OFf	Remote routers can only bridge to devices on the same LAN as the router.

Default

Off (Disabled)

Command Mode

System mode

Example

The following example enables individual remote routers to bridge to each other through the router:

Host> set passthru on

set pattern

To create a pattern for user-defined bridge filters or IP generic filters, use the set pattern command.

SEt patternname [PAttern = hexpattern binarypattern decimalpattern [OFfset = number] [FRom=BEGINNING | TYPEFIELD | IPHDR | TCPHDR | UDPHDR | TCPDATA | UDPDATA] PATTERNName = patternname]

Syntax Description

patternname	Name of the pattern. Can consist of 1 to 7 characters.
PAttern	Value of the pattern. Must be between 1 and 6 bytes, separated by spaces.
hexpattern	Bit or byte pattern in hexadecimal format. A wildcard in the form X can be used in place of a digit.
binarypattern	Bit or byte pattern in binary format. Will be displayed in hexadecimal format with the show pattern command. A wildcard in the form X can be used in place of a digit.
decimalpattern	Bit or byte pattern in decimal format. Will be displayed in hexadecimal format with the show pattern command.
OFfset number	Number of bytes from the pattern reference point that indicate where the pattern starts. Must be between 0 and 127. The offset value and the pattern value cannot be more than 128 bytes. If you do not enter a value, defaults to 0.
FRom	Pattern reference point, from where the offset value is counted. Can be beginning, typefield, iphdr, tcphdr, udphdr, tcpdata, or udpdata. If you do not enter one, the default is beginning.
BEGINNING	The beginning of the packet.
TYPEFIELD	The beginning of the packet typefield.
IPHDR	The beginning of the IP header.
TCPHDR	The beginning of the TCP header.
UDPHDR	The beginning of the UDP header.
TCPDATA	The beginning of the TCP data.
UDPDATA	The beginning of the UDP data.

Default

No patterns are configured.

Command Mode

System mode

Usage Guideline

Patterns can be used by all profiles.

Examples

The following example creates a pattern test1:

Host> set test1 pattern 00 5a 2c offset 10 from typefield

The following example changes the offset on the pattern test1 to 6 bytes:

Host> set test1 off 6

The following example changes the pattern name from test1 to test2:

Host> set test1 pattern test2

Related Commands

reset pattern
set filter
show filter
show pattern

set type

To create a bridge filter based on packet type, use the set type command.

SEt TYpe=type [ACcept | BLock] [IGnore | DEmand]

Syntax Description

type	Ethernet packet type. Up to four hexadecimal digits with no spaces.
ACcept	Only packets with this packet type are forwarded to the connection.
BLock	Packets of this type are not sent to the connection.
IGnore	Packets of this type are not counted in the demand and timeout calculations that bring the ISDN line up and disconnect it.
DEmand	Only packets of this type are counted in the demand and timeout calculations that bring the ISDN line up and disconnect it.

Default

No type filters configured.

Command Mode

System or profile mode

Usage Guidelines

Type filters configured in system mode are used by all profiles. Type filters configured at the profile level are used by that profile only.

Although multiple type filters can be defined as accept, block, demand or ignore, the most recently defined filter determines which set of filters is used. When the packet comes in, it is evaluated by the most recent filter. If that filter blocks the packet, the packet is dropped, even if another filter would have accepted the packet.

By default, type filters apply only to broadcast and multicast packets. If unicast filtering is enabled with the set unicastfilter command, type filters apply to broadcast, multicast, and unicast packets.

Type filtering is independent of Ethernet address filtering. Packets must match address filters and type filters before being forwarded to or blocked from the ISDN line.

Examples

The following example configures profile 2503 to prevent broadcast and multicast from activating the ISDN line (however, if the ISDN line already connected, the packets are forwarded to the line):

Host:2503> set type 1 accept

Host:2503> set type 1 demand

Because there are no Ethernet packets of type 1, this command blocks all broadcast and multicast traffic.

Refer to the appendix "Ethernet Packet Types" for further information.

set unicastfilter

To enable or disable unicast filtering, use the set unicastfilter command.

SEt UNicastfilter ON | OFf

Syntax Description

ON	Enables unicast filtering.
OFf	Disables unicast filtering.

Default

Off

Command Mode

System mode

Usage Guidelines

Unicast filtering applies to type filters configured with the set type command and to user-defined filters configured with the set filter command.

Example

The following example enables unicast filtering for the router:

Host> set unicast on

Related Commands

set type
set filter
show filter

show address

To display information about the router system and profile address configurations, use the show address command.

SHow [connection] ADdress

Syntax Description

connection

When a connection number is specified, the address associated with the connection is displayed.

Default

None

Command Mode

System or profile mode

Examples

The following example shows the output of the show address command at the system mode:

Host> show address

INT 00 40 f9 12 00 11  Static

LAN 00 a0 24 41 92 fd  Age:         7

2 00 00 1b 4f b2 cc  Age:         18

2 00 00 c0 75 07 4c  Age:        156

2 6a 6b 1b 4f b2 cc  Age:       2162

Number of Ethernet Addresses: 5

IP Address: 0.0.0.0

Ethernet Address: 00 40 f9 12 00 11

Subnet Mask: 0.0.0.0

Default Gateway: 0.0.0.0

IPX Default Gateway:  NONE

SAP Helper:  NONE

The following example shows the output of the show address command for the profile 2503:

Host:2503> show address

2 00 40 f9 ff ff ff  Static

2 00 40 f9 12 34 56  Static

Number of Ethernet Addresses: 2

Ethernet address: 00 40f9 0036 AD

If user profile 2503 has a connection number, entering the show connection address command displays the router profile address configuration.

describes the fields shown in the display, as well as others that might appear when the command is used.

Table 8-1 Show Address Field Descriptions 

Field	Description
INT	Ethernet address of the internal profile
LAN	Ethernet address of the LAN profile
Number of Ethernet addresses	The number of Ethernet addresses associated with the system mode
IP Address	IP address of the system mode
Ethernet Address	Ethernet address of the router
Subnet Mask	Subnet mask of the system mode
Default Gateway	Default gateway of the system mode
SAP Helper	Service advertising protocol helper

show ethernet

To generate a performance report of the Ethernet interface, use the show ethernet command. The report provides information on different kinds of errors and interface traffic. The data in this report has accumulated since the router was last powered up.

SHow ETher

Default

None

Command Mode

System or profile mode

Example

The following example shows output from the show ethernet command:

Host> show ethernet

Ethernet Statistics:

 Multiple Colls:    0

 Internal Tx Errs:  0

 Missed Frames:     0

 Frames Received:   0

 Frames Sent:       0

 Octets Received:   0

 Octets Sent:       0

show filter

To display user-defined filters, use the show filter command.

SHow [id] FIlter

Syntax Description

id	The ID number assigned to the filter by the router. Displays that filter only, including all patterns that make up the filter.

Default

None

Usage Guidelines

In system mode, this command displays all filters configured in system mode. In profile mode, this command displays filters configured in system mode and filters defined in profile mode. This command also indicates whether unicast filtering is enabled.

Example

The following example shows output from the show filter command:

Host> show filter

Unicast Filtering OFF

Filters

1 Filter BLOCK arp

3 Filter ACCEPT DEMAND john

Related Commands

set filter
set unicastfilter

show pattern

To display all patterns configured with the set pattern command, use the show pattern command.

SHow [patternname] PATtern

Syntax Description

patternname

Displays a specific pattern by the name assigned with the set pattern command.

Default

None

Command Mode

System mode

Usage Guidelines

Patterns can be used by all profiles.

Example

The following example shows output from the show pattern command:

Host> show pattern

Patterns

Name    Offset   From      Pattern

patta        6   BEGINNING 00 03

pattb        0   BEGINNING 08 09

pattc        0   BEGINNING 55 66

pattd        0   BEGINNING 01 0d

6544>

Table 8-2 defines the fields shown in the display.

Table 8-2 Show Pattern Field Descriptions

Field	Description
Name	Name of the pattern.
Offset	Number of bytes from the reference point where the pattern starts.
From	Lists the pattern starting reference point. Can be BEGINNING or TYPEFIELD, IPHDR, TCPHDR, UDPHDR, TCPDATA, UDPDATA.
Pattern	Byte pattern.

show type

To display filter types, use the show type command. Ethernet packets contain a 2-byte type field that describes the protocol type of the packet.

SHow TYpe

Syntax Description

This command has no arguments or keywords.

Default

None

Command Mode

System mode

Example

The following example shows output from the show type command:

Host> show type

Type forwarding mode ANY

Type demand mode     ANY

Unicast Filtering    OFF