Session parameters commands

session-parameters

Syntax

session-parameters

Context

config>router>ldp

Platforms

Supported on all 7210 SAS platforms as described in this document.

Description

Commands in this context configure peer-specific parameters.

peer

Syntax

[no] peer ip-address

Context

config>router>ldp>session-parameters

Platforms

Supported on all 7210 SAS platforms as described in this document.

Description

This command configures parameters for an LDP peer.

Parameters

ip-address

Specifies the IP address of the LDP peer in dotted-decimal notation.

Values

ipv4-address

a.b.c.d

ipv6-address

x:x:x:x:x:x:x:x: (eight 16-bit pieces)

x:x:x:x:x:x:d.d.d.d

x - [0..FFFF]H

d - [0..255]D

adv-adj-add-only

Syntax

[no] adv-adj-addr-only

Context

config>router>ldp>session-params>peer

Platforms

Supported on all 7210 SAS platforms as described in this document.

Description

This command provides a means for an LDP router to advertise only the local IPv4 or IPv6 interfaces it uses to establish hello adjacencies with an LDP peer. By default, when a router establishes an LDP session with a peer, it advertises in an LDP Address message the addresses of all local interfaces to allow the peer to resolve LDP FECs distributed by this router. Similarly, a router sends a Withdraw Address message to all its peers to withdraw a local address if the corresponding interface went down or was deleted.

This new option reduces CPU processing when a large number of LDP neighbors come up or go down. The new CLI option is strongly recommended in mobile backhaul networks where the number of LDP peers can be large.

The no form of this command reverts LDP to the default behavior of advertising all local interfaces.

Default

no adv-adj-addr-only

dod-label-distribution

Syntax

[no] dod-label-distribution

Context

config>router>ldp>session-params>peer

Platforms

Supported on all 7210 SAS platforms as described in this document.

Description

This command enables the use of the LDP Downstream-on-Demand (DoD) label distribution procedures.

When this option is enabled, LDP sets the A-bit in the Label Initialization message when the LDP session to the peer is established. When both peers set the A-bit, they will both use the DoD label distribution method over the LDP session (RFC 5036).

This feature can only be enabled on a link-level LDP session and therefore applies to prefix labels only, not service labels.

As soon as the link LDP session comes up, the router sends a label request to its DoD peer for the FEC prefix corresponding to the peer LSR ID. The DoD peer LSR ID is found in the basic Hello discovery messages the peer used to establish the Hello adjacency with the router.

Similarly, if the router and the directly attached DoD peer enters into extended discovery and established a targeted LDP session, the router immediately sends a label request for the FEC prefix corresponding to the peer LSR ID found in the extended discovery messages.

However, the router will not advertise any <FEC, label> bindings, including the FEC of its own LSR-id, unless the DoD peer requested it using a Label Request Message.

When the DoD peer sends a label request for any FEC prefix, the router replies with a <FEC, label> binding for that prefix if the FEC was already activated on the router. If not, the router replies with a notification message containing the status code of ‟no route.” The router will not attempt in the latter case to send a label request to the next-hop for the FEC prefix when the LDP session to this next-hop uses the DoD label distribution mode, therefore the reference to single-hop LDP DoD procedures.

As soon as the link LDP session comes up, the router sends a label request to its DoD peer for the FEC prefix corresponding to the peer LSR ID. The DoD peer LSR ID is found in the basic Hello discovery messages the peer used to establish the Hello adjacency with the router.

Similarly, if the router and the directly attached DoD peer enter into extended discovery and established a targeted LDP session, the router immediately sends a label request for the FEC prefix corresponding to the peer LSR ID found in the extended discovery messages. The peer address must be the peer LSR ID address.

The no form of this command disables the DoD label distribution with an LDP neighbor.

Default

no dod-label-distribution

export-addresses

Syntax

export-addresses policy-name [policy-name ... (up to 5 max)]

no export-addresses

Context

config>router>ldp>session-params>peer

Platforms

Supported on all 7210 SAS platforms as described in this document.

Description

This command specifies the export prefix policy to local addresses advertised to this peer.

Policies are configured in the config>router>policy-options context. A maximum of five policy names can be specified.

The no form of this command removes the policy from the configuration.

Default

no export-addresses

Parameters

policy-name

Specifies the export prefix route policy name. Allowed values are any string up to 32 characters composed of printable, 7-bit ASCII characters excluding double quotes. If the string contains spaces, use double quotes to delimit the start and end of the string. The specified names must already be defined.

export-prefixes

Syntax

export-prefixes policy-name [policy-name ... (up to 5 max)]

no export-prefixes

Context

config>router>ldp>session-params>peer

Platforms

Supported on all 7210 SAS platforms as described in this document.

Description

This command specifies the export route policy used to determine which prefixes received from other LDP and T-LDP peers are redistributed to this LDP peer via the LDP/T-LDP session to this peer. A prefix that is filtered out (deny) will not be exported. A prefix that is filtered in (accept) will be exported.

If no export policy is specified, all FEC prefixes learned will be exported to this LDP peer. This policy is applied in addition to the global LDP policy and targeted session policy.

Policies are configured in the config>router>policy-options context. A maximum of five policy names can be specified. The peer address must be the peer LSR ID address.

The no form of this command removes the policy from the configuration.

Default

no export-prefixes

Parameters

policy-name

Specifies the export prefix route policy name. Allowed values are any string up to 32 characters composed of printable, 7-bit ASCII characters excluding double quotes. If the string contains spaces, use double quotes to delimit the start and end of the string. The specified names must already be defined.

fec-limit

Syntax

fec-limit limit [log-only] [threshold percentage]

no fec-limit

Context

config>router>ldp>session-params>peer

Platforms

Supported on all 7210 SAS platforms as described in this document.

Description

This command configures a limit on the number of FECs that an LSR will accept from a specific peer and add into the LDP label database. The limit applies to the aggregate count of all FEC types including service FEC. When the limit is reached, any FEC received will be released back to the peer. This behavior is different from the per-peer import policy, which will still accept the FEC into the label database but will not resolve it.

When the FEC limit for a peer is reached, the LSR performs the following actions:

  1. generates a trap and a syslog message

  2. generates an LDP notification message with the LSR overload status TLV for each LDP FEC type, including service FEC, to this peer only if this peer advertised support for the LSR overload sub-TLV via the LSR Overload Protection Capability TLV at session initialization

  3. releases, with LDP Status Code of "No_Label_Resources", any new FEC, including service FEC, from this peer that exceeds the limit

If a legitimate FEC is released back to a peer while the FEC limit was exceeded, the user must have a means to replay that FEC back to the router LSR after the condition clears. This is done automatically if the peer is an SR OS-based router and supports the LDP overload status TLV (SR OS 11.0.R5 and higher). Third-party peer implementations must support the LDP overload status TLV or provide a manual command to replay the FEC.

The threshold percentage option allows to set a threshold value when a trap and a syslog message are generated as a warning to the user in addition to when the limit is reached. The default value for the threshold when not configured is 90%.

The log-only option causes a trap and syslog message to be generated when reaching the threshold and limit. However, LDP labels are not released back to the peer.

If the user decreases the limit value such that it is lower than the current number of FECs accepted from the peer, the LDP LSR raises the trap for exceeding the limit. In addition, it will set overload for peers that signaled support for the LDP overload protection capability TLV. However, no existing resolved FECs from the peer that does not support the overload protection capability TLV should be deprogrammed or released.

A different trap is released when crossing the threshold in the upward direction, when reaching the FEC limit, and when crossing the threshold in the downward direction. However the same trap will not be generated more often than two minutes apart if the number of FECs oscillates around the threshold or the FEC limit.

The no form of this command disables FEC limiting.

Default

no fec-limit

Parameters

limit

Specifies the aggregate count of FECs of all types that can be accepted from this LDP peer.

Values

1 to 4294967295

log-only

Keyword to enable generation of a syslog message when the threshold and limit has been reached. However, LDP labels are not released back to the peer.

percentage

Specifies the threshold value, as a percentage, that triggers a warning and syslog message and trap to be sent.

Values

1 to 100

fec-type-capability

Syntax

fec-type-capability

Context

config>router>ldp>session-params>peer

config>router>ldp>interface-params>interface>ipv4

config>router>ldp>interface-params>interface>ipv6 (supported on 7210 SAS-Mxp only)

Platforms

Supported on all 7210 SAS platforms as described in this document.

Description

Commands in this context configure FEC type capabilities for the session or interface.

p2mp

Syntax

p2mp {enable | disable}

Context

config>router>ldp>session-params>peer>fec-type-capability

Platforms

7210 SAS-T, 7210 SAS-Mxp, 7210 SAS-R6, and 7210 SAS-R12

Description

This command enables or disables P2MP FEC capability for the session.

Default

p2mp disable

Parameters

enable

Keyword to enable P2MP FEC capability for the session.

disable

Keyword to disable P2MP FEC capability for the session.

prefix-ipv4

Syntax

prefix-ipv4 {enable | disable}

Context

config>router>ldp>session-params>peer>fec-type-capability

Platforms

Supported on all 7210 SAS platforms as described in this document.

Description

This command enables or disables the IPv4 prefix FEC capability on the session or interface.

Default

prefix-ipv4 enable

Parameters

enable

Keyword to enable IPv4 prefix FEC capability on the session or interface.

disable

Keyword to disable IPv4 prefix FEC capability on the session or interface.

prefix-ipv6

Syntax

prefix-ipv6 {enable | disable}

Context

config>router>ldp>session-params>peer>fec-type-capability

Platforms

7210 SAS-Mxp

Description

This command enables or disables the IPv6 prefix FEC capability on the session or interface.

Default

prefix-ipv4 enable

Parameters

enable

Keyword to enable IPv6 prefix FEC capability on the session or interface.

disable

Keyword to disable IPv6 prefix FEC capability on the session or interface.

fec129-cisco-interop

Syntax

[no] fec129-cisco-interop

Context

config>router>ldp>session-params>peer

Platforms

Supported on all 7210 SAS platforms as described in this document.

Description

This command configures whether LDP will provide translation between non-compliant FEC 129 Cisco formats. Peer LDP sessions must be manually configured toward the non-compliant Cisco PEs.

When enabled, Cisco non-compliant format is used to send and interpret received label release messages. The FEC129 SAII and TAII fields will be reversed.

The no form of this command disables use and support of Cisco non-compliant forms. The peer address must be the peer LSR ID address.

Default

no fec129-cisco-interop

import-prefixes

Syntax

import-prefixes policy-name [policy-name ... (up to 5 max)]

no import-prefixes

Context

config>router>ldp>session-params>peer

Platforms

Supported on all 7210 SAS platforms as described in this document.

Description

This command configures the import FEC prefix policy to determine which prefixes received from this LDP peer are imported and installed by LDP on this node. If resolved, these FEC prefixes are redistributed to other LDP and T-LDP peers. A FEC prefix that is filtered out (deny) will not be imported. A FEC prefix that is filtered in (accept) will be imported.

If no import policy is specified, the node will import all prefixes received from this LDP/T-LDP peer. This policy is applied in addition to the global LDP policy and targeted session policy. Policies are configured in the config>router>policy-options context. A maximum of five policy names can be specified. The specified names must already be defined. The peer address must be the peer LSR ID address.

The no form of this command removes the policy from the configuration.

Default

no import-prefixes

Parameters

policy-name

Specifies the import prefix route policy name. Allowed values are any string up to 32 characters composed of printable, 7-bit ASCII characters excluding double quotes. If the string contains spaces, use double quotes to delimit the start and end of the string.

pe-id-mac-flush-interop

Syntax

[no] pe-id-mac-flush-interop

Context

config>router>ldp>session-params>peer

Platforms

Supported on all 7210 SAS platforms as described in this document.

Description

This command enables the addition of the PE-ID TLV in the LDP MAC withdrawal (mac-flush) message, under specific conditions, and modifies the mac-flush behavior for interoperability with other vendors that do not support the flush-all-from-me vendor-specific TLV. This flag can be enabled on a per LDP peer basis and allows the flush-all-from-me interoperability with other vendors. When the pe-id-mac-flush-interop flag is enabled for a specific peer, the current mac-flush behavior is modified in terms of mac-flush generation, mac-flush propagation and behavior upon receiving a mac-flush.

The mac-flush generation will be changed depending on the type of event and according to the following rules.

  • Any all-from-me mac-flush event will trigger a mac-flush all-but-mine message (RFC 4762 compliant format) with the addition of a PE-ID TLV. The PE-ID TLV contains the IP address of the sending PE.

  • Any all-but-mine mac-flush event will trigger a mac-flush all-but-mine message without the addition of the PE-ID TLV, as long as the source spoke-SDP is not part of an end-point.

  • Any all-but-mine mac-flush event will trigger a mac-flush all-but-mine message with the addition of the PE-ID TLV, if the source spoke-SDP is part of an end-point and the spoke-SDP goes from the down/standby state to the active state. In this case, the PE-ID TLV will contain the IP address of the PE to which the previous active spoke-SDP was connected.

Any other case will follow the existing mac-flush procedures.

When the pe-id-mac-flush-interop flag is enabled for a specific LDP peer, the mac-flush ingress processing is modified according to the following rules.

  • Any received all-from-me mac-flush will follow the existing mac-flush all-from-me rules, regardless of the existence of the PE-ID.

  • Any received all-but-mine mac-flush will take into account the received PE-ID, that is, all the MAC addresses associated with the PE-ID will be flushed. If the PE-ID is not included, the MAC addresses associated with the sending PE will be flushed.

  • Any other case will follow the existing mac-flush procedures.

When a mac-flush message has to be propagated (for an ingress SDP-binding to an egress SDP-binding) and the pe-id-mac-flush-interop flag is enabled for the ingress and egress TLDP peers, the following behavior is observed.

  • If the ingress and egress bindings are spoke-SDP, the PE will propagate the mac-flush message with its own PE-ID.

  • If the ingress binding is an spoke-SDP and the egress binding a mesh-SDP, the PE will propagate the mac-flush message without modifying the PE-ID included in the PE-ID TLV.

  • If the ingress binding is a mesh-SDP and the egress binding a spoke-SDP, the PE will propagate the mac-flush message with its own PE-ID.

  • When ingress and egress bindings are mesh-SDP, the mac-flush message is never propagated. This is the behavior regardless of the pe-id-mac-flush-interop flag configuration.

The PE-ID TLV is never added when generating a mac-flush message on a B-VPLS if the send-bvpls-flush command is enabled in the I-VPLS. In the same way, no PE-ID is added when propagating mac-flush from a B-VPLS to a I-VPLS when the propagate-mac-flush-from-bvpls command is enabled. Mac-flush messages for peers within the same I-VPLS or within the same B-VPLS domain follow the preceding procedures.

Default

no pe-id-mac-flush-interop