6.3. MSDP Configuration Command Reference

6.3.1. Command Hierarchies

6.3.1.1. Configuration Commands

config
— router
[no] msdp
[no] active-source-limit number
export policy-name [policy-name]
— no export
[no] group group-name
export policy-name [policy-name]
— no export
import policy-name [policy-name]
— no import
local-address address
mode {mesh-group | standard}
[no] peer peer-address
authentication-key [authentication-key | hash-key] [hash | hash2]
[no] default-peer
export policy-name [policy-name]
— no export
import policy-name [policy-name]
— no import
local-address address
receive-msdp-msg-rate number interval seconds [threshold number]
[no] shutdown
receive-msdp-msg-rate number interval seconds [threshold number]
[no] shutdown
import policy-name [policy-name]
— no import
local-address address
[no] peer peer-address
authentication-key [authentication-key | hash-key] [hash | hash2]
[no] default-peer
export policy-name [policy-name]
— no export
import policy-name [policy-name]
— no import
local-address address
receive-msdp-msg-rate number interval seconds [threshold number]
[no] shutdown
receive-msdp-msg-rate number interval seconds [threshold number]
rpf-table {rtable-m | rtable-u | both}
— no rpf-table
sa-timeout seconds
— no sa-timeout
[no] shutdown
[no] source prefix/mask

6.3.2. Command Descriptions

6.3.2.1. MSDP Commands

msdp

Syntax 
[no] msdp
Context 
config>router
Description 

This command enables a Multicast Source Discovery Protocol (MSDP) instance. When an MSDP instance is created, the protocol is enabled. To start or suspend execution of the MSDP protocol without affecting the configuration, use the [no] shutdown command.

For the MSDP protocol to function, at least one peer must be configured.

When MSDP is configured and started an appropriate event message should be generated.

When the no form of the command is executed, all sessions must be terminated and an appropriate event message should be generated.

When all peering sessions are terminated, an event message per peer is not required.

The no form of the command deletes the MSDP protocol instance, removing all associated configuration parameters.

Default 

no msdp

active-source-limit

Syntax 
active-source-limit number
no active-source-limit
Context 
config>router>msdp
config>router>msdp>group
config>router>msdp>group>peer
Description 

This option controls the maximum number of active source messages that will be accepted by Multicast Source Discovery Protocol (MSDP), effectively controlling the number of active sources that can be stored on the system.

The no form of this command sets no limit on the number of source active records.

Default 

no active-source-limit

Parameters 
number—
This parameter defines how many active sources can be maintained by MSDP.
Values—
0 to 1000000

 

receive-msdp-msg-rate

Syntax 
receive-msg-rate number interval seconds [threshold number]
no receive-msg-rate
Context 
config>router>msdp
config>router>msdp>peer
config>router>msdp>group
config>router>msdp>group>peer
Description 

This command limits the number of Multicast Source Discovery Protocol (MSDP) messages that are read from the TCP session. It is possible that an MSDP/ RP router may receive a large number of MSDP protocol message packets in a particular source active message.

After the number of MSDP packets (including source active messages) defined in the threshold have been processed, the rate of all other MSDP packets is rate limited by no longer accepting messages from the TCP session until the time (seconds) has elapsed.

The no form of this command sets no limit on the number of MSDP and source active limit messages that will be accepted.

Default 

no receive-msdp-msg-rate

Parameters 
number—
Defines the number of MSDP messages (including source active messages) that are read from the TCP session per the number of seconds.
Values—
10 to 10000

 

Default—
0
interval seconds
This defines the time that, together with the number parameter, defines the number of MSDP messages (including source active messages) that are read from the TCP session within the configured number of seconds.
Values—
1 to 600

 

Default—
0
threshold number—
This number reflects the number of MSDP messages can be processed before the MSDP message rate limiting function described above is activated; this is particularly of use during at system startup and initialization.
Values—
1 to 1000000

 

Default—
0

shutdown

Syntax 
[no] shutdown
Context 
config>router>msdp
config>router>msdp>peer
config>router>msdp>group
Description 

The shutdown command administratively disables the entity. When disabled, an entity does not change, reset, or remove any configuration settings or statistics. Many entities must be explicitly enabled using the no shutdown command and must be shut down before they may be deleted.

Unlike other commands and parameters where the default state is not indicated in the configuration file, shutdown and no shutdown are always indicated in system generated configuration files.

The no form of the command puts an entity into the administratively enabled state.

Default 

no shutdown

authentication-key

Syntax 
authentication-key [authentication-key | hash-key] [hash | hash2]
no authentication-key
Context 
config>router>msdp>peer
config>router>msdp>group>peer
Description 

This command configures a Message Digest 5 (MD5) authentication key to be used with a specific Multicast Source Discovery Protocol (MSDP) peering session. The authentication key must be configured per peer as such no global or group configuration is possible.

The no form of the command configures acceptance of all MSDP messages and disables the MD5 signature option authentication key.

Default 

no authentication-key

Parameters 
authentication-key—
The authentication key. Allowed values are any string up to 256 characters long composed of printable, 7-bit ASCII characters. If the string contains special characters (#, $, spaces, and so on), enclose the entire string in quotation marks (“ ”).
hash-key—
The hash key. The key can be any combination of ASCII characters up to 451 characters in length (encrypted). If spaces are used in the string, enclose the entire string in quotation marks (“ ”).

This is useful when a user must configure the parameter, but, for security purposes, the actual unencrypted key value is not provided.

hash—
Specifies the key is entered in an encrypted form. If the hash or hash2 parameter is not used, the key is assumed to be in an unencrypted, clear text form. For security, all keys are stored in encrypted form in the configuration file with the hash or hash2 parameter specified
hash2—
Specifies the key is entered in a more complex encrypted form that involves more variables than the key value alone, meaning that the hash2 encrypted variable cannot be copied and pasted. If the hash or hash2 parameter is not used, the key is assumed to be in an unencrypted, clear text form. For security, all keys are stored in encrypted form in the configuration file with the hash or hash2 parameter specified.

data-encapsulation

Syntax 
[no] data-encapsulation
Context 
config>router>msdp
Description 

This command configures a rendezvous point (RP) using Multicast Source Discovery Protocol (MSDP) to encapsulate multicast data received in MSDP register messages inside forwarded MSDP source-active messages.

Default 

data-encapsulation

default-peer

Syntax 
default-peer
no default-peer
Context 
config>router>msdp>peer
config>router>msdp>group>peer
Description 

Using the default peer mechanism, a peer can be selected as the default Multicast Source Discovery Protocol (MSDP) peer. As a result, all source-active messages from the peer will be accepted without the usual peer-reverse-path-forwarding (RPF) check.

The MSDP peer-RPF check is different from the normal multicast RPF checks. The peer-RPF check is used to stop source-active messages from looping. A router validates source-active messages originated from other routers in a deterministic fashion.

A set of rules is applied in order to validate received source-active messages, and the first rule that applies determines the peer-RPF neighbor. All source-active messages from other routers are rejected. The rules applied to source-active messages originating at Router S received at Router R from Router N are as follows:

  1. If Router N and router S are one and the same, then the message is originated by a direct peer-RPF neighbor and will be accepted.
  2. If Router N is a configured peer, or a member of the Router R mesh group then its source-active messages are accepted.
  3. If Router N is the Border Gateway Protocol (BGP) next hop of the active multicast RPF route toward Router S then Router N is the peer-RPF neighbor and its source-active messages are accepted.
  4. If Router N is an external BGP peer of Router R and the last autonomous system (AS) number in the BGP AS-path to Router S is the same as Router N’s AS number, then Router N is the peer-RPF neighbor, and its source-active messages are accepted.
  5. If Router N uses the same next hop as the next hop to Router S, then Router N is the peer-RPF neighbor, and its source-active messages are accepted.
  6. If Router N fits none of the above rules, then Router N is not a peer-RPF neighbor, and its source-active messages are rejected.
Default 

No default peer is established and all active source messages must be RPF checked.

export

Syntax 
export policy-name [policy-name]
no export
Context 
config>router>msdp
config>router>msdp>peer
config>router>msdp>group
config>router>msdp>group>peer
Description 

This command specifies the policies to export source active state from the source active list into Multicast Source Discovery Protocol (MSDP).

If multiple policy names are specified, the policies are evaluated in the order they are specified. The first policy that matches is applied. If multiple export commands are issued, the last command entered will override the previous command. A maximum of five policy names can be specified.

The no form of the command applies no export policies and all SA entries are announced.

Default 

no export

Parameters 
policy-name—
Specifies the export policy name. Up to five policy-name arguments can be specified.

If you configure an export policy at the global level, each individual peer inherits the global policy. If you configure an export policy at the group level, each individual peer in a group inherits the group’s policy. If you configure an export policy at the peer level, then policy only applies to the peer where it is configured.

group

Syntax 
[no] group group-name
Context 
config>router>msdp
Description 

This command enables access to the context to create or modify a Multicast Source Discovery Protocol (MSDP) group. To configure multiple MSDP groups, include multiple group statements.

By default, the group’s options are inherited from the global MSDP options. To override these global options, group-specific options within the group statement can be configured.

If the group name provided is already configured then this command only provides the context to configure the options pertaining to this group.

If the group name provided is not already configured, then the group name must be created and the context to configure the parameters pertaining to the group should be provided. In this case, the $ prompt to indicate that a new entity (group) is being created should be used.

For a group to be of use, at least one peer must be configured.

Default 

no group

Parameters 
group-name—
Species a unique name for the MSDP group.

import

Syntax 
import policy-name [policy-name]
no import
Context 
config>router>msdp
config>router>msdp>peer
config>router>msdp>group
config>router>msdp>group>peer
Description 

This command specifies the policies to import source active state from Multicast Source Discovery Protocol (MSDP) into source active list.

If multiple policy names are specified, the policies are evaluated in the order they are specified. The first policy that matches is applied. If multiple import commands are issued, the last command entered will override the previous command. A maximum of five policy names can be specified.

If you configure an import policy at the global level, each individual peer inherits the global policy.

If you configure an import policy at the group level, each individual peer in a group inherits the group’s policy.

If you configure an import policy at the peer level, then policy only applies to the peer where it is configured.

The no form of the command applies no import policies and all source active messages are allowed.

Default 

no import

Parameters 
policy-name—
Specifies the import policy name. Up to five policy-name arguments can be specified.

local-address

Syntax 
local-address address
no local-address
Context 
config>router>msdp
config>router>msdp>peer
config>router>msdp>group
config>router>msdp>group>peer
Description 

This command configures the local end of a Multicast Source Discovery Protocol (MSDP) session. For MSDP to function, at least one peer must be configured. When configuring a peer, you must include this local-address command to configure the local end of the MSDP session. This address must be present on the node and is used to validate incoming connections to the peer and to establish connections to the remote peer.

If the user enters this command, then the address provided is validated and will be used as the local address for MSDP peers from that point. If a subsequent local-address command is entered, it will replace the existing configuration and existing sessions will be terminated.

Similarly, when the no form of this command is entered, the existing local-address will be removed from the configuration and the existing sessions will be terminated.

Whenever a session is terminated, all information pertaining to and learned from that peer will be removed.

Whenever a new peering session is created or a peering session is lost, an event message should be generated.

The no form of this command removes the local-address from the configuration.

Default 

No local address is configured.

Parameters 
address—
Specifies an existing address on the node.

mode

Syntax 
mode {mesh-group | standard}
Context 
config>router>msdp>group
Description 

This command configures groups of peers in a full mesh topology to limit excessive flooding of source-active messages to neighboring peers.

Multicast Source Discovery Protocol (MSDP) peers can be configured grouped in a full-mesh topology that prevents excessive flooding of source-active messages to neighboring peers.

In a meshed configuration, all members of the group must have a peer connection with every other mesh group member. If this rule is not adhered to, then unpredictable results may occur.

Default 

mode standard

Parameters 
mesh-group—
Specifies that source-active message received from a mesh group member are always accepted but are not flooded to other members of the same mesh group. These source-active messages are only flooded to non-mesh group peers or members of other mesh groups.
standard—
Specifies a non-meshed mode.

peer

Syntax 
[no] peer peer-address
Context 
config>router>msdp
config>router>msdp>group
Description 

This command configures peer parameters. Multicast Source Discovery Protocol (MSDP) must have at least one peer configured. A peer is defined by configuring a local-address that can be used by this node to set up a peering session and the address of a remote MSDP router, It is the address of this remote peer that is configured in this command and it identifies the remote MSDP router address.

After peer relationships are established, the MSDP peers exchange messages to advertise active multicast sources. It may be required to have multiple peering sessions in which case multiple peer statements should be included in the configurations.

By default, the options applied to a peer are inherited from the global or group-level. To override these inherited options, include peer-specific options within the peer statement.

If the peer address provided is already a configured peer, then this command only provides the context to configure the parameters pertaining to this peer.

If the peer address provided is not already a configured peer, then the peer instance must be created and the context to configure the parameters pertaining to this peer should be provided. In this case, the $ prompt to indicate that a new entity (peer) is being created should be used.

The peer address provided will be validated and, if valid, will be used as the remote address for an MSDP peering session.

When the no form of this command is entered, the existing peering address will be removed from the configuration and the existing session will be terminated. Whenever a session is terminated, all source active information pertaining to and learned from that peer will be removed. Whenever a new peering session is created or a peering session is lost, an event message should be generated.

At least one peer must be configured for MSDP to function.

Default 

none

Parameters 
peer-address—
The address configured in this statement must identify the remote MSDP router that the peering session must be established with.

rpf-table

Syntax 
rpf-table {rtable-m | rtable-u | both}
no rpf-table
Context 
config>router>msdp
Description 

This command configures the sequence of route tables used to find a Reverse Path Forwarding (RPF) interface for a particular multicast route.

By default, only the unicast route table is looked up to calculate RPF interface towards the source/rendezvous point. However, the operator can specify one of the following options:

  1. use the unicast route table only
  2. use the multicast route table only
  3. use both the route tables
Default 

rpf-table rtable-u

Parameters 
rtable6-m—
Specifies that only the multicast route table will be used by the multicast protocol (PIM) for IPv4 RPF checks. This route table will contain routes submitted by static routes, ISIS and OSPF.
rtable6-u—
Specifies only that the unicast route table will be used by the multicast protocol (PIM) for IPv4 RPF checks. This route table will contain routes submitted by all the unicast routing protocols.
both—
Will always look up first in the multicast route table and, if there is a route, it will use it. If PIM does not find a route in the first lookup, it will try to find it in the unicast route table. Rtable-m is checked before rtable6-u.

sa-timeout

Syntax 
sa-timeout seconds
no sa-timeout
Context 
config>router>msdp
Description 

This command configures the value for the SA entries in the cache. If these entries are not refreshed within the timeout value, they are removed from the cache. Normally, the entries are refreshed at least once a minute. But under high load with many of MSDP peers, the refresh cycle could be incomplete. A higher timeout value (more than 90) could be useful to prevent instabilities in the MSDP cache.

Default 

90

Parameters 
seconds—
Specifies the time, in seconds, to wait for a response from the peer before declaring the peer unavailable.
Values—
90 to 600

 

source

Syntax 
[no] source ip-prefix/mask
Context 
config>router>msdp
Description 

This command limits the number of active source messages the router accepts from sources in the specified address range.

If the prefix and mask provided is already a configured then this command only provides the context to configure the parameters pertaining to this active source-message filter.

If the prefix and mask provided is not already a configured, then the source node instance must be created and the context to configure the parameters pertaining to this node should be provided. In this case, the $ prompt to indicate that a new entity (source) is being created should be used.

The no form of this message removes the source active rate limiter for this source address range.

Default 

None. The source active msdp messages are not rate limited based on the source address range.

Parameters 
ip-prefix—
The IP prefix in dotted decimal notation for the range used by the ABR to advertise that summarizes the area into another area.
Values—
ip-prefix/mask: ip-prefix a.b.c.d (host bits must be 0)

 

mask—
The subnet mask for the range expressed as a decimal integer mask length or in dotted decimal notation.
Values—
0 to 32 (mask length), 0.0.0.0 to 255.255.255.255 (dotted decimal)