Cisco IOS Software Releases 12.2 S

Table Of Contents

NSF/SSO—Any Transport over MPLS and AToM Graceful Restart

Contents

Prerequisites for AToM NSF

Supported Hardware

Supported Port Adapters

Supported RSPs

Supported VIPs

Neighbor Routers in the MPLS HA Environment

Stateful Switchover

Nonstop Forwarding for Routing Protocols

Restrictions for AToM NSF

Information About AToM NSF

How AToM NSF Works

Checkpointing AToM Information

Checkpointing Troubleshooting Tips

How to Configure AToM NSF

Configuring AToM

Configuring SSO on the Route Processors

Configuring Nonstop Forwarding on the Routers

Configuring MPLS LDP Graceful Restart

Verifying the Configuration

Configuration Examples for AToM NSF

Ethernet to VLAN Interworking with AToM NSF: Example

Additional References

Related Documents

Standards

MIBs

RFCs

Technical Assistance

Command Reference

debug acircuit checkpoint

debug mpls l2transport checkpoint

show acircuit checkpoint

show mpls l2transport checkpoint

show mpls l2transport vc

Feature Information for AToM NSF

NSF/SSO—Any Transport over MPLS and AToM Graceful Restart

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First Published: August 11, 2004

Last Updated: February 23, 2006

Cisco nonstop forwarding (NSF) with stateful switchover (SSO) is effective at increasing availability of network services. Cisco NSF with SSO provides continuous packet forwarding, even during a network processor hardware or software failure. In a redundant system, the secondary processor recovers control plane service during a critical failure in the primary processor. SSO synchronizes the network state information between the primary and the secondary processor.

Any Transport over MPLS (AToM) uses NSF, SSO, and Graceful Restart to allow a Route Processor (RP) to recover from a disruption in control plane service without losing its MPLS forwarding state.

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Note In this document, the NSF/SSO—Any Transport over MPLS and AToM Graceful Restart feature is referred to as AToM NSF for brevity.

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Finding Feature Information in This Module

Your Cisco IOS software release may not support all of the features documented in this module. To reach links to specific feature documentation in this module and to see a list of the releases in which each feature is supported, use the "Feature Information for AToM NSF" section.

Finding Support Information for Platforms and Cisco IOS Software Images

Use Cisco Feature Navigator to find information about platform support and Cisco IOS software image support. Access Cisco Feature Navigator at http://www.cisco.com/go/fn. You must have an account on Cisco.com. If you do not have an account or have forgotten your username or password, click Cancel at the login dialog box and follow the instructions that appear.

Contents

•Prerequisites for AToM NSF

•Restrictions for AToM NSF

•Information About AToM NSF

•How to Configure AToM NSF

•Configuration Examples for AToM NSF

•Additional References

•Command Reference

•Feature Information for AToM NSF

Prerequisites for AToM NSF

This section lists the following prerequisites:

•Supported Hardware

•Neighbor Routers in the MPLS HA Environment

•Stateful Switchover

•Nonstop Forwarding for Routing Protocols

Supported Hardware

The AToM NSF feature is supported on the Cisco 7500 series routers, with the port adapters, versatile interface processors (VIPs), and route switch processors (RSPs) listed in the following sections.

Supported Port Adapters

•GEIP+

•PA-2FE-TX, PA-2FE-FX

•PA-2H, PA-H

•PA-4E, PA-8E

•PA-4T+ and/or PA-8T-232, PA-8T-V35, PA-8T-X21

•PA-A3-OC3-MM, PA-A3-OC3-SMI, PA-A3-OC3-SML

•PA-FE-TX, PA-FE-FX

•PA-MC_8E1/120, MC-4E1, MC-2E1, MC-8T1, MC-4T1, MC-2T1

•PA-MC-8E1IMA

•PA-MC-8TE1+

•PA-MC-E3

•PA-MC-STM1-MM, PA-MC-STM1-SMI

•PA-MC-T3, PA-MC-2T3+

•PA-POS-OC3-MM, PA-POS-OC3-SMI, PA-POS-OC3-SML

Supported RSPs

•RSP4

•RSP4+

•RSP8

•RSP16

Supported VIPs

•VIP2-50

•VIP4-50

•VIP4-80

•VIP6-80

Neighbor Routers in the MPLS HA Environment

AToM NSF requires that neighbor networking devices be able to perform AToM GR. The Cisco 7200 and Cisco 7500 routers are capable of supporting AToM GR and can be used as neighbor networking devices.

Stateful Switchover

To perform AToM NSF, Route Processors must be configured for SSO and Graceful Restart. See the Stateful Switchover feature module for more information.

Nonstop Forwarding for Routing Protocols

You must enable NSF on the routing protocols running between the provider (P) routers, provider edge (PE) routers, and customer edge (CE) routers. The routing protocols are the following:

•Border Gateway Protocol (BGP)

•Open Shortest Path First (OSPF)

•Intermediate System-to-Intermediate System (IS-IS)

See the Cisco Nonstop Forwarding feature module for more information.

Restrictions for AToM NSF

AToM NSF includes the following restrictions:

•Tag Distribution Protocol (TDP) sessions are not supported. Only Label Distribution Protocol (LDP) sessions are supported.

•AToM NSF cannot be configured on label-controlled ATM (LC-ATM) interfaces.

•AToM NSF supports AToM L2VPN Interworking. However, Layer 2 Tunnel Protocol Version 3 (L2TPv3) Interworking is not supported.

•AToM NSF interoperates with Layer 2 Local Switching. However, AToM NSF has no effect on interfaces configured for local switching.

•Disable fair queueing on serial interfaces or distributed Cisco Express Forwarding will not work on the interfaces.

•On the Cisco 7500 series routers, distributed Cisco Express Forwarding is needed to support AToM NSF.

Information About AToM NSF

To configure AToM NSF, you should understand the following concepts:

•How AToM NSF Works

•Checkpointing AToM Information

How AToM NSF Works

AToM NSF improves the availability of a service provider's network that uses AToM to provide Layer 2 VPN services to its customers. HA provides the ability to detect failures and handle them with minimal disruption to the service being provided. AToM NSF is achieved by SSO and NSF mechanisms. A standby RP provides control-plane redundancy. The control plane state and data plane provisioning information for the attachment circuits (ACs) and AToM pseudowires (PWs) are checkpointed to the standby RP to provide NSF for AToM L2VPNs.

Checkpointing AToM Information

Checkpointing is a function that copies state information from the active RP to the backup RP, thereby ensuring that the backup RP has the latest information. If the active RP fails, the backup RP can take over.

For the AToM NSF feature, the checkpointing function copies the active RP's information bindings to the backup RP. The active RP sends updates to the backup RP when information is modified.

To display checkpointing data, issue the show acircuit checkpoint command on the active and backup RPs. The active and backup RPs have identical copies of the information.

Checkpointing Troubleshooting Tips

To help troubleshoot checkpointing errors, use the following commands:

•Use the debug acircuit checkpoint command to enable checkpointing debug messages for ACs.

•Use the debug mpls l2transport checkpoint command to enable checkpointing debug messages for AToM.

•Use the show acircuit checkpoint command to display the AC checkpoint information.

•Use the show mpls l2transport checkpoint command to display whether checkpointing is allowed, how many AToM VCs were bulk-synced (on the active RP), and how many AToM VCs have checkpoint data (on the standby RP).

•Use the show mpls l2transport vc detail command to display details of VC checkpointed information.

How to Configure AToM NSF

To configure AToM NSF, perform the following tasks:

•Configuring AToM (required)

•Configuring SSO on the Route Processors (required)

•Configuring Nonstop Forwarding on the Routers (required)

•Configuring MPLS LDP Graceful Restart (required)

•Verifying the Configuration (optional)

Configuring AToM

AToM virtual circuits (VCs) must be configured on the router. See the Any Transport over MPLS feature module for information on configuring AToM. For configuring L2VPN Interworking, see the L2VPN Interworking feature module.

Configuring SSO on the Route Processors

Route processors must be configured for SSO. See the Stateful Switchover feature module for configuration information.

Configuring Nonstop Forwarding on the Routers

You must enable Nonstop Forwarding on the routing protocols running between the P routers, PE routers, and CE routers. The routing protocols include OSPF, IS-IS, and BGP. See the Cisco Nonstop Forwarding feature module for configuration information.

Configuring MPLS LDP Graceful Restart

MPLS LDP Graceful Restart (GR) is enabled globally. When you enable LDP GR, it has no effect on existing LDP sessions. LDP GR is enabled for new sessions that are established after the feature has been globally enabled.

Perform this task to configure MPLS LDP GR.

SUMMARY STEPS

1. enable

2. configure terminal

3. ip cef [distributed]

4. mpls ldp graceful-restart

5. interface type slot/port

6. mpls ip

7. mpls label protocol {ldp | tdp | both}

DETAILED STEPS

	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. •Enter your password if prompted.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	ip cef [distributed] Example: Router(config)# ip cef distributed	Enables Cisco Express Forwarding.
Step 4	mpls ldp graceful-restart Example: Router (config)# mpls ldp graceful-restart	Enables the router to protect the LDP bindings and MPLS forwarding state during a disruption in service.
Step 5	interface type slot/port Example: Router(config)# interface pos 3/0	Specifies an interface and enters interface configuration mode.
Step 6	mpls ip Example: Router(config-if)# mpls ip	Configures MPLS hop-by-hop forwarding for an interface.
Step 7	mpls label protocol {ldp | tdp | both} Example: Router(config-if)# mpls label protocol ldp	Configures the use of LDP for an interface. •You must use LDP, because TDP sessions are not supported. You can also issue the mpls label protocol ldp command in global configuration mode, which enables LDP on all interfaces configured for MPLS.

Verifying the Configuration

The following commands help verify that AToM NSF has been configured correctly:

show mpls ldp neighbor with the graceful-restart keyword	Displays the Graceful Restart information for LDP sessions.
show mpls ldp graceful-restart	Displays Graceful Restart sessions and session parameters.

Configuration Examples for AToM NSF

This section provides the following configuration example:

•Ethernet to VLAN Interworking with AToM NSF: Example

Ethernet to VLAN Interworking with AToM NSF: Example

The following example shows how to configure AToM NSF on two PE routers.

PE1

PE2

ip cef distributed ! redundancy mode sso ! hw-module slot 2 image slot1:rsp-pv-mz hw-module slot 3 image slot1:rsp-pv-mz ! mpls ldp graceful-restart mpls ip mpls label protocol ldp mpls ldp router-id Loopback0 force mpls ldp advertise-tags ! pseudowire-class atom-eth  encapsulation mpls  interworking ethernet ! interface Loopback0  ip address 10.8.8.8 255.255.255.255 ! interface FastEthernet1/1/0  xconnect 10.9.9.9 123 encap mpls pw-class atom_eth interface POS6/1/0  ip address 10.1.1.1 255.255.255.0  mpls ip  mpls label protocol ldp  clock source internal  crc 32 ! interface Loopback0  ip address 10.8.8.8 255.255.255.255  no shutdown ! router ospf 10  nsf  network 10.8.8.8 0.0.0.0 area 0  network 19.1.1.1 0.0.0.0 area 0

ip cef distributed ! redundancy mode sso ! hw-module slot 2 image slot1:rsp-pv-mz hw-module slot 3 image slot1:rsp-pv-mz mpls ldp graceful-restart mpls ip mpls label protocol ldp mpls ldp router-id Loopback0 force mpls ldp advertise-tags ! pseudowire-class atom-eth  encapsulation mpls  interworking eth ! interface Loopback0  ip address 10.9.9.9 255.255.255.255 ! interface FastEthernet3/0/0  ip route-cache cef ! interface FastEthernet3/0/0.3  encapsulation dot1Q 10  xconnect 10.8.8.8 123 encap mpls pw-class atom_eth interface POS1/0/0  ip address 10.1.1.2 255.255.255.0  mpls ip  mpls label protocol ldp  clock source internal  crc 32 ! interface Loopback0  ip address 10.9.9.9 255.255.255.255 ! router ospf 10  nsf  network 10.9.9.9 0.0.0.0 area 0  network 10.1.1.2 0.0.0.0 area 0

Additional References

The following sections provide references related to AToM NSF.

Related Documents

Related Topic	Document Title
Stateful switchover	Stateful Switchover
MPLS Label Distribution Protocol	MPLS Label Distribution Protocol (LDP)
Cisco nonstop forwarding	Cisco Nonstop Forwarding
Any Transport over MPLS	Any Transport over MPLS
L2VPN Interworking configuration	L2VPN Interworking

Standards

Standards	Title
No new or modified standards are supported by this feature, and support for existing standards has not been modified by this feature.	—

MIBs

MIBs	MIBs Link
MPLS Label Distribution Protocol MIB Version 8 Upgrade	To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL: http://www.cisco.com/go/mibs

RFCs

RFCs	Title
RFC 3036	LDP Specification
RFC 3478	Graceful Restart Mechanism for Label Distribution

Technical Assistance

Description	Link
The Cisco Technical Support & Documentation website contains thousands of pages of searchable technical content, including links to products, technologies, solutions, technical tips, and tools. Registered Cisco.com users can log in from this page to access even more content.	http://www.cisco.com/techsupport

Command Reference

This section documents only new and modified commands. All other commands used with this feature are documented in feature modules related to AToM, LDP NSF/SSO and Graceful Restart, and stateful switchover.

•debug acircuit checkpoint

•debug mpls l2transport checkpoint

•show acircuit checkpoint

•show mpls l2transport checkpoint

•show mpls l2transport vc

debug acircuit checkpoint

To enable the display of attachment circuit (AC) events when Any Transport over MPLS (AToM) is configured for nonstop forwarding/stateful switchover (NSF/SSO) and Graceful Restart, use the debug acircuit checkpoint command in privileged EXEC mode. To disable the display of these messages, use the no form of this command.

debug acircuit checkpoint

no debug acircuit checkpoint

Syntax Description

This command has no arguments or keywords.

Defaults

Debugging of the AToM NSF/SSO and Graceful Restart feature is not enabled.

Command Modes

Privileged EXEC

Command History

Release	Modification
12.2(25)S	This command was introduced.
12.2(28)SB	This command was integrated into Cisco IOS Release 12.2(28)SB.

Usage Guidelines

Use debug commands with care. They use a significant amount of CPU time and can affect system performance.

Examples

The debut acircuit checkpoint command is issued on the active RP:

Router# debug mpls l2transport checkpoint

Router# debug acircuit checkpoint

Router# show debug

AToM HA:

  AToM checkpointing events and errors debugging is on

AC HA:

  Attachment Circuit Checkpoint debugging is on

Router# conf terminal

Enter configuration commands, one per line.  End with CNTL/Z.

Router(config)# interface Fa5/1/1.2

Router(config-subif)# xconnect 10.55.55.2 1002 pw-class mpls

AToM HA [10.55.55.2, 1002]: Build provision msg, SSM sw/seg 8192/8194 [0x2000/0x2002] PW i
d 9216 [0x2400] local label 21

AC HA: Dynamic Sync. Event:4 Sw:8192[2000] Se:16385[4001]

AToM HA: CF sync send complete

AC HA CF: Sync send complete. Code:0

On the standby RP, the following messages indicate that it receives checkpointing data:

AC HA [10.55.55.2, 1002]: Add to WaitQ. Flags:1

AToM HA [10.55.55.2, 1002]: Received 32-byte provision version 1 CF message

AC HA CF: ClientId:89, Entity:0 Length:40

AToM HA [10.55.55.2, 1002]: Process chkpt msg provision [1], ver 1

AToM HA [10.55.55.2, 1002]: Reserved SSM sw/seg 8192/8194 [0x2000/0x2002] PW id 9216 [0x24
00]

AC HA: Process Msg:35586. Ptr:44CBFD90. Val:0

AC HA: Sync. Event:4 CktType:4 Sw:8192[2000] Se:16385[4001]

AC HA [10.55.55.2, 1002]: Remove from WaitQ. Flags:1[OK][OK]

During a switchover from the active to the backup route processor, the debug messages look similar to the following:

%HA-5-MODE: Operating mode is hsa, configured mode is sso.

AC HA RF: CId:83, Seq:710, Sta:RF_STATUS_OPER_REDUNDANCY_MODE_CHANGE, Opr:5, St:STANDBY HO
T, PSt:ACTIVE

AToM HA: CID 84, Seq 715, Status RF_STATUS_OPER_REDUNDANCY_MODE_CHANGE, Op 5, State STANDB
Y HOT, Peer ACTIVE

AC HA RF: CId:83, Seq:710, Sta:RF_STATUS_PEER_PRESENCE, Opr:0, St:STANDBY HOT, PSt:ACTIVE

AToM HA: CID 84, Seq 715, Status RF_STATUS_PEER_PRESENCE, Op 0, State STANDBY HOT, Peer AC
TIVE

AC HA RF: CId:83, Seq:710, Sta:RF_STATUS_PEER_COMM, Opr:0, St:STANDBY HOT, PSt:DISABLED

AToM HA: CID 84, Seq 715, Status RF_STATUS_PEER_COMM, Op 0, State STANDBY HOT, Peer DISABL
ED

%HA-2-CUTOVER_NOTICE: Cutover initiated. Cease all console activity until system restarts.

%HA-2-CUTOVER_NOTICE: Do not add/remove RSPs or line cards until switchover completes.

%HA-2-CUTOVER_NOTICE: Deinitializing subsystems...

%OIR-6-REMCARD: Card removed from slot 4, interfaces disabled

%OIR-6-REMCARD: Card removed from slot 5, interfaces disabled

%OIR-6-REMCARD: Card removed from slot 9, interfaces disabled

%HA-2-CUTOVER_NOTICE: Reinitializing subsystems...

%HA-2-CUTOVER_NOTICE: System preparing to restart...

%HA-5-NOTICE: Resuming initialization...

AC HA RF: CId:83, Seq:710, Sta:RF_STATUS_REDUNDANCY_MODE_CHANGE, Opr:7, St:STANDBY HOT, PS
t:DISABLED

.

.

.

%LDP-5-GR: LDP restarting gracefully.  Preserving forwarding state for 250 seconds.

AC HA RF: CId:83, Seq:710, Sta:RF_PROG_ACTIVE, Opr:0, St:ACTIVE, PSt:DISABLED

AToM HA: CID 84, Seq 715, Event RF_PROG_ACTIVE, Op 0, State ACTIVE, Peer DISABLED

AC HA: Process Msg:35588. Ptr:0. Val:0

AC HA: Switchover: Standby->Active

AC HA RF: Reconciling

Related Commands

Command	Description
debug mpls l2transport checkpoint	Enables the display of AToM events when AToM is configured for NSF/SSO and Graceful Restart.

debug mpls l2transport checkpoint

To enable the display of Any Transport over MPLS (AToM) events when AToM is configured for nonstop forwarding/stateful switchover (NSF/SSO) and Graceful Restart, use the debug mpls l2transport checkpoint command in privileged EXEC mode. To disable the display of these messages, use the no form of this command.

debug mpls l2transport checkpoint

no debug mpls l2transport checkpoint

Syntax Description

This command has no arguments or keywords.

Defaults

Debugging of the AToM NSF/SSO and Graceful Restart feature is not enabled.

Command Modes

Privileged EXEC

Command History

Release	Modification
12.2(25)S	This command was introduced.
12.2(28)SB	This command was integrated into Cisco IOS Release 12.2(28)SB.

Usage Guidelines

Use debug commands with care. They use a significant amount of CPU time and can affect system performance.

Examples

In the following example, the output shows that NSF/SSO and Graceful Restart synchronize the data between the active and backup route processors after an AToM virtual circuit (VC) is created. (Both the debug mpls l2transport checkpoint and the debug acircuit checkpoint commands are enabled in this example.)

The debug mpls l2transport checkpoint command is enabled on the active RP:

Router# debug mpls l2transport checkpoint

Router# debug acircuit checkpoint

Router# show debug

AToM HA:

  AToM checkpointing events and errors debugging is on

AC HA:

  Attachment Circuit Checkpoint debugging is on

Router# conf terminal

Enter configuration commands, one per line.  End with CNTL/Z.

Router(config)# interface Fa5/1/1.2

Router(config-subif)# xconnect 10.55.55.2 1002 pw-class mpls

AToM HA [10.55.55.2, 1002]: Build provision msg, SSM sw/seg 8192/8194 [0x2000/0x2002] PW i
d 9216 [0x2400] local label 21

AC HA: Dynamic Sync. Event:4 Sw:8192[2000] Se:16385[4001]

AToM HA: CF sync send complete

AC HA CF: Sync send complete. Code:0

On the standby RP, the following messages indicate that it receives checkpointing data:

AC HA [10.55.55.2, 1002]: Add to WaitQ. Flags:1

AToM HA [105.55.55.2, 1002]: Received 32-byte provision version 1 CF message

AC HA CF: ClientId:89, Entity:0 Length:40

AToM HA [10.55.55.2, 1002]: Process chkpt msg provision [1], ver 1

AToM HA [10.55.55.2, 1002]: Reserved SSM sw/seg 8192/8194 [0x2000/0x2002] PW id 9216 [0x24
00]

AC HA: Process Msg:35586. Ptr:44CBFD90. Val:0

AC HA: Sync. Event:4 CktType:4 Sw:8192[2000] Se:16385[4001]

AC HA [10.55.55.2, 1002]: Remove from WaitQ. Flags:1[OK][OK]

During a switchover from the active to the backup route processor, the debug messages look similar to the following:

%HA-5-MODE: Operating mode is hsa, configured mode is sso.

AC HA RF: CId:83, Seq:710, Sta:RF_STATUS_OPER_REDUNDANCY_MODE_CHANGE, Opr:5, St:STANDBY HO
T, PSt:ACTIVE

AToM HA: CID 84, Seq 715, Status RF_STATUS_OPER_REDUNDANCY_MODE_CHANGE, Op 5, State STANDB
Y HOT, Peer ACTIVE

AC HA RF: CId:83, Seq:710, Sta:RF_STATUS_PEER_PRESENCE, Opr:0, St:STANDBY HOT, PSt:ACTIVE

AToM HA: CID 84, Seq 715, Status RF_STATUS_PEER_PRESENCE, Op 0, State STANDBY HOT, Peer AC
TIVE

AC HA RF: CId:83, Seq:710, Sta:RF_STATUS_PEER_COMM, Opr:0, St:STANDBY HOT, PSt:DISABLED

AToM HA: CID 84, Seq 715, Status RF_STATUS_PEER_COMM, Op 0, State STANDBY HOT, Peer DISABL
ED

%HA-2-CUTOVER_NOTICE: Cutover initiated. Cease all console activity until system restarts.

%HA-2-CUTOVER_NOTICE: Do not add/remove RSPs or line cards until switchover completes.

%HA-2-CUTOVER_NOTICE: Deinitializing subsystems...

%OIR-6-REMCARD: Card removed from slot 4, interfaces disabled

%OIR-6-REMCARD: Card removed from slot 5, interfaces disabled

%OIR-6-REMCARD: Card removed from slot 9, interfaces disabled

%HA-2-CUTOVER_NOTICE: Reinitializing subsystems...

%HA-2-CUTOVER_NOTICE: System preparing to restart...

%HA-5-NOTICE: Resuming initialization...

AC HA RF: CId:83, Seq:710, Sta:RF_STATUS_REDUNDANCY_MODE_CHANGE, Opr:7, St:STANDBY HOT, PS
t:DISABLED

.

.

.

%LDP-5-GR: LDP restarting gracefully.  Preserving forwarding state for 250 seconds.

AC HA RF: CId:83, Seq:710, Sta:RF_PROG_ACTIVE, Opr:0, St:ACTIVE, PSt:DISABLED

AToM HA: CID 84, Seq 715, Event RF_PROG_ACTIVE, Op 0, State ACTIVE, Peer DISABLED

AC HA: Process Msg:35588. Ptr:0. Val:0

AC HA: Switchover: Standby->Active

AC HA RF: Reconciling

Related Commands

Command	Description
debug acircuit checkpoint	Enables the display of AToM attachment circuit events when AToM is configured for NSF/SSO and Graceful Restart.

show acircuit checkpoint

To display checkpointing information for each attachment circuit (AC), use the show acircuit checkpoint command in privileged EXEC mode.

show acircuit checkpoint

Syntax Description

This command has no arguments or keywords.

Command Modes

Privileged EXEC

Command History

Release	Modification
12.2(25)S	This command was introduced.
12.2(28)SB	This command was integrated into Cisco IOS Release 12.2(28)SB.

Usage Guidelines

This command is used for interface-based attachment circuits. For Frame Relay and ATM circuits, use the following commands to show redundancy information:

•debug atm ha-error

•debug atm ha-events

•debug atm ha-state

•debug atm l2transport

•debug frame-relay redundancy

Examples

The following show acircuit checkpoint command displays information about the ACs that have been check-pointed. The output varies, depending on whether the command output is for the active or standby route processor (RP).

On the active RP, the command displays the following output:

Router# show acircuit checkpoint

AC HA Checkpoint info:

Last Bulk Sync: 1 ACs

 AC    IW    XC    Id  VCId   Switch    Segment  St  Chkpt

----  ----  ----  ---  ----  --------  --------  --  -----

HDLC  LIKE  ATOM    3   100      1000      1000   0    N

VLAN  LIKE  ATOM    2  1002      2001      2001   3    Y

On the standby RP, the command displays the following output::

Router# show acircuit checkpoint

AC HA Checkpoint info:

 AC    IW    XC    Id  VCId   Switch    Segment  St  F-SLP

----  ----  ----  ---  ----  --------  --------  --  -----

HDLC  LIKE  ATOM    3   100         0         0   0   001

VLAN  LIKE  ATOM    2  1002      2001      2001   2   000

Table 1 describes the significant fields shown in the display.

Table 1 show acircuit checkpoint Field Descriptions 

Field	Description
Last Bulk Sync	The number of ACs that were sent to the backup RP during the last bulk synchronization between the active and backup RPs.
AC	The type of attachment circuit.
IW	The type of interworking, either like-to-like (AToM) or any-to-any (Interworking).
XC	The type of cross-connect. Only AToM ACs are checkpointed.
ID	This field varies, depending on the type of attachment circuit. For Ethernet VLANs, the ID is the VLAN ID. For PPP and High-Level Data Link Control (HDLC), the ID is the AC circuit ID.
VCID	The configured virtual circuit ID.
Switch	An ID used to correlate the control plane and data plane contexts for this virtual circuit (VC). This is an internal value that is not for customer use.
Segment	An ID used to correlate the control plane and data plane contexts for this VC. This is an internal value that is not for customer use.
St	The state of the attachment circuit. This is an internal value that is not for customer use.
Chkpt	Whether the information about the AC was checkpointed.
F-SLP	Flags that provide more information about the state of the AC circuit. These values are not for customer use.

Related Commands

Command	Description
show mpls l2transport vc	Displays AToM status information.
show mpls l2transport vc checkpoint	Displays the status of the checkpointing process for both the active and standby RPs.

show mpls l2transport checkpoint

To display checkpointing information about Any Transport over MPLS (AToM) virtual circuits (VCs), use the show mpls l2transport checkpoint command in privileged EXEC mode.

show mpls l2transport checkpoint

Syntax Description

This command has no arguments or keywords.

Command Modes

Privileged EXEC

Command History

Release	Modification
12.2(25)S	This command was introduced.
12.2(28)SB	This command was integrated into Cisco IOS Release 12.2(28)SB.

Examples

The output of the commands varies, depending on whether the output reflects the active or standby route processor (RP).

On the active RP, the command displays the following output:

Router# show mpls l2transport checkpoint

AToM Checkpoint info for active RP

Checkpointing is allowed

Bulk-sync checkpointed state for 1 VC

On the standby RP, the command displays the following output::

Router# show mpls l2transport checkpoint

AToM HA Checkpoint info for standby RP

1 checkpoint information block in use

In general, the output on the active RP shows that checkpointing information was sent to the backup RP. The output on the backup RP shows that checkpointing information was received from the active RP.

Related Commands

Command	Description
show mpls l2transport vc	Displays information about the checkpointed data when checkpointing is enabled.

show mpls l2transport vc

To display information about Any Transport over MPLS (AToM) virtual circuits (VCs) that have been enabled to route Layer 2 packets on a router, use the show mpls l2transport vc command in privileged EXEC mode.

show mpls l2transport vc [vcid vcid] | [vcid-min vcid-max] [interface name [local-circuit-id]] [destination ip-address | name] [detail]

Syntax Description

vcid vc-id	(Optional) VC ID assigned to the router.
vc-id-min vc-id-max	(Optional) VCs that are assigned the range of VC IDs that you specify. The range is from 1 to 4294967295. (This argument is primarily for legacy implementations.)
interface	(Optional) Interface or subinterface of the router that has been enabled to transport Layer 2 packets. This keyword lets you display information about the VCs that have been assigned VC IDs on that interface or subinterface.
name	(Optional) Name of the interface or subinterface.
local-circuit-id	(Optional) Number assigned to the local circuit. This argument value applies only to the following transport types: •For Frame Relay, enter the data-link connection identifier (DLCI) of the permanent virtual circuit (PVC). •For ATM adaptation layer 5 (AAL5) and Cell Relay, enter the virtual path identifier/virtual channel identifier (VPI/VCI) of the PVC. •For Ethernet VLANs, enter the VLAN number.
destination	(Optional) Information about the VCs that have been assigned VC IDs for the remote router you specify.
ip-address	(Optional) IP address of the remote router.
name	(Optional) Name assigned to the remote router.
detail	(Optional) Detailed information about the VCs that have been assigned VC IDs.

Command Default

If you do not specify any keywords or arguments, the command displays a summary of all the VCs.

Command Modes

Privileged EXEC

Command History

Release	Modification
12.1(8a)E	This command was introduced.
12.0(21)ST	This command was integrated into Cisco IOS Release 12.0(21)ST.
12.0(23)S	The interface and destination keywords were added.
12.2(14)S	This command was integrated into Cisco IOS Release 12.2(14)S.
12.2(15)T	This command was integrated into Cisco IOS Release 12.2(15)T.
12.0(25)S	This command was updated with new output and fields to display information about tunnel selection and ATM cell relay port mode.
12.2(25)S	This command was updated with new output and fields for nonstop forwarding (NSF), statefulswitchover (SSO), and Graceful Restart (GR) abilities.
12.2(28)SB	This command was integrated into Cisco IOS Release 12.2(28)SB and implemented on the Cisco 10000 series routers. Example output was changed for the Cisco 10000 series router, and two fields (SSO Descriptor and SSM segment/switch IDs) were removed from the output, because they ar not supported.

Examples

The output of the commands varies, depending on the type of Layer 2 packets being transported over the AToM VCs.

The following sample output shows information about the interfaces and VCs that have been configured to transport various Layer 2 packets on the router:

Router# show mpls l2transport vc

Local intf           Local circuit      Dest address    VC ID      Status

-------------        ------------------ --------------- ---------- ----------

Se5/0/0/1:1/0        FR DLCI 55         10.0.0.1        55         UP

ATM4/0/0.1           ATM AAL5 0/100     10.0.0.1        100        UP

ATM4/0/0.2           ATM AAL5 0/200     10.0.0.1        200        UP

ATM4/0/0.300         ATM AAL5 0/300     10.0.0.1        300        UP

Table 2 describes the significant fields displayed in the display.

Table 2 show mpls l2transport vc Field Descriptions 

Field	Description
Local intf	Interface on the local router that has been enabled to transport Layer 2 packets.
Local circuit	Type and number (if applicable) of the local circuit. The output shown in this column varies, according to transport type: •For Frame Relay, the output shows the DLCI of the PVC. •For ATM cell relay and AAL5, the output shows the VPI/VCI of the PVC. •For Ethernet VLANs, the output shows the VLAN number. •For PPP and High-Level Data Link Control (HDLC), the output shows the interface number.
Dest address	IP address of the remote router's interface that is the other end of the VC.
VC ID	Virtual circuit identifier assigned to one of the interfaces on the router.
Status	Status of the VC. The status can be one of the following: UP—The VC is in a state where it can carry traffic between the two VC endpoints. A VC is up when both imposition and disposition interfaces are programmed. •The disposition interfaces is programmed if the VC has been configured and the client interface is up. •The imposition interface is programmed if the disposition interface is programmed and you have a remote VC label and an IGP label. The Interior Gateway Protocol (IGP) label can be implicit null in a back-to-back configuration. (An IGP label means there is a label switched path (LSP) to the peer.) DOWN—The VC is not ready to carry traffic between the two VC endpoints. Use the detail keyword to determine the reason that the VC is down. ADMIN DOWN—The VC has been disabled by a user. RECOVERING—The VC is recovering from a stateful switchover.

The following sample output shows information about VCs that have been configured to transport Layer 2 packets:

Router# show mpls l2transport vc detail 

Local interface: AT4/0 up, line protocol up, ATM AAL5 0/200 up 

Destination address: 13.13.13.13, VC ID: 100, VC status: up

    Tunnel label: imp-null, next hop point2point

    Output interface: PO0/1/0, imposed label stack {16}

  Create time: 00:16:44, last status change time: 00:15:45

  Signaling protocol: LDP, peer 13.13.13.13:0 up

    MPLS VC labels: local 16, remote 16

    Group ID: local 12, remote 1

    MTU: local 1500, remote 1500

    Remote interface description: 

  Sequencing: receive disabled, send disabled

  VC statistics:

    packet totals: receive 56, send 55

    byte totals:   receive 10181, send 10569

    packet drops:  receive 0, send 0 

Table 3 describes the significant fields shown in the display.

Table 3 show mpls l2transport vc detail Field Descriptions 

Field	Description
Local interface	The interface on the local router that has been enabled to send and receive Layer 2 packets. The interface varies, depending on the transport type. The output also shows the status of the interface.
line protocol	The status of the line protocol on the edge-facing interface.
ATM AAL5 0/200	The type, number (if applicable), and status of the local circuit. The output varies, depending on the transport type: •For Frame Relay, the output shows the DCLI of the PVC. •For ATM cell relay and AAL5, the output shows the VPI/VCI of the PVC. •For Ethernet VLANs, the output shows the VLAN number.
Destination address	The IP address of the remote router specified for this VC. You specify the destination IP address as part of the mpls l2transport route command.
VC ID	The virtual circuit identifier assigned to the interface on the router.
VC status	The status of the VC. The status can be one of the following: UP—The VC is in a state where it can carry traffic between the two VC endpoints. A VC is up when both imposition and disposition interfaces are programmed. •The disposition interface is programmed if the VC has been configured and the client interface is up. •The imposition interface is programmed if the disposition interface is programmed and a remote VC label and an IGP label exist. The IGP label can be an implicit null in a back-to-back configuration. (An IGP label means there is n LSP to the peer.) DOWN—The VC is not ready to carry traffic between the two VC endpoints. ADMIN DOWN—The VC has been disabled by a user.
Tunnel label	An IGP label used to route the packet over the MPLS backbone to the destination router with the egress interface. The first part of the output displays the type of label. The second part of output displays the route information. The tunnel label information can display any of the following states: •imp-null: The provider core (P) router is absent and the tunnel label will not be used. Alternatively, imp-null can signify traffic engineering tunnels between the PE routers. •unassigned: The label has not been assigned. •no route: The label is not in the routing table. •no adjacency: The adjacency for the next hop is missing. •not ready, no route: An IP route for the peer does not exist in the routing table. •not ready, not a host table: The route in the routing table for the remote peer router is not a host route. •not ready, CEF disabled: Cisco Express Forwarding is disabled. •not ready, LFIB disabled: The Multiprotocol Label Switchng (MPLS) switching subsystem is disabled. •not ready, Label Forwarding Information Base (LFIB) entry present: The tunnel label exists in the LFIB, but the VC is down.
Output interface	The interface on the remote router that has been enabled to transmit and receive Layer 2 packets.
imposed label stack	Summary of the MPLS label stack used to direct the VC to the PE router.
Create time	The time when the VC was provisioned.
last status change time	The last time the VC state changed.
Signaling protocol	The type of protocol used to send the MPLS labels. The output also shows the status of the peer router.
MPLS VC labels	The local VC label is a disposition label, which determines the egress interface of an arriving packet from the MPLS backbone. The remote VC label is a disposition VC label of the remote peer router.
Group ID	The local group ID is used to group VCs locally. The remote group ID is used by the peer to group several VCs.
MTU	The maximum transmission unit (MTU) specified for the local and remote interfaces.
Remote interface description	The interface on the remote router that has been enabled to send and receive Layer 2 packets.
Sequencing	Indicates whether sequencing of out-of-order packets is enabled or disabled.
packet totals	The number of packets sent and received. Received packets are those AToM packets received from the MPLS core. Sent packets are those AToM packets sent to the MPLS core. This number does not include dropped packets.
byte totals	The number of packets sent and received from the core-facing interface, including the payload, VC label, and AToM control word (if present).
packet drops	The number of packets that were dropped while being sent to the MPLS core or received from the MPLS core.

The following example shows information about the NSF/SSO and GR capability. The SSO portion indicates when checkpointing data has either been sent (on active) or received (on standby). When SSO data has not been successfully sent or has been released, the SSO information is not shown.

Router# show mpls l2transport vc detail

Local interface: Fa5/1/1.2 down, line protocol down, Eth VLAN 2 up

  Destination address: 55.55.55.2, VC ID: 1002, VC status: down

    Output interface: Se4/0/3, imposed label stack {16}

    Preferred path: not configured

    Default path: active

    Tunnel label: imp-null, next hop point2point

  Create time: 02:03:29, last status change time: 02:03:26

  Signaling protocol: LDP, peer 55.55.55.2:0 down

    MPLS VC labels: local 16, remote unassigned

    Group ID: local 0, remote unknown

    MTU: local 1500, remote unknown

    Remote interface description:

  Sequencing: receive disabled, send disabled

  VC statistics:

    packet totals: receive 0, send 0

    byte totals:   receive 0, send 0

    packet drops:  receive 0, send 0

Table 4 describes the significant fields shown in the display.

Table 4 show mpls l2transport vc detail Field Descriptions 

Field	Description
Local interface	Interface on the local router that has been enabled to send and receive Layer 2 packets. The interface varies, depending on the transport type. The output also shows the status of the interface.
line protocol	Status of the line protocol on the edge-facing interface.
local circuit	Type, number (if applicable) and status of the local circuit. The output varies, depending on the transport type: •For Frame Relay, the output shows the DCLI of the PVC. •For ATM cell relay and ATM AAL5, the output shows the VPI/VCI of the PVC. •For Ethernet VLANs, the output shows the VLAN number.
Destination address	IP address of the remote router specified for this VC. You specify the destination IP address as part of the mpls l2transport route command.
VC ID	Virtual circuit identifier assigned to the interface on the router.
VC status	Status of the VC. The status can be one of the following: UP—The VC is in a state where it can carry traffic between the two VC endpoints. A VC is up when both imposition and disposition interfaces are programmed. •The disposition interface is programmed if the VC has been configured and the client interface is up. •The imposition interface is programmed if the disposition interface is programmed and a remote VC label and an IGP label exist. The IGP label can be an implicit null in a back-to-back configuration. (An IGP label means there is a LSP to the peer.) DOWN—The VC is not ready to carry traffic between the two VC endpoints. ADMIN DOWN—The VC has been disabled by a user.
Preferred path	Path that was assigned to the VC and the status of that path. The path can be a Multiprotocol Label Switching (MPLS) traffic engineering tunnel or an IP address or hostname of a peer provider edge (PE) router.
Default path	Status of the default path, which can be disabled or active. By default, if the preferred path fails, the router uses the default path. However, you can disable the router from using the default path when the preferred path fails by specifying the disable-fallback keyword with the preferred-path command.
Tunnel label	An IGP label used to route the packet over the MPLS backbone to the destination router with the egress interface. The first part of the output displays the type of label. The second part of output displays the route information. The tunnel label information can display any of the following states: •imp-null: The provider (P) router is absent and the tunnel label will not be used. Alternatively, imp-null can signify traffic engineering tunnels between the PE routers. •unassigned: The label has not been assigned. •no route: The label is not in the routing table. •no adjacency: The adjacency for the next hop is missing. •not ready, no route: An IP route for the peer does not exist in the routing table. •not ready, not a host table: The route in the routing table for the remote peer router is not a host route. •not ready, Cisco Express Forwarding (CEF) disabled: Cisco Express Forwarding is disabled. •not ready, LFIB disabled: The MPLS switching subsystem is disabled. •not ready, label forwarding information base (LFIB) entry present: The tunnel label exists in the LFIB, but the VC is down.
Output interface	Interface on the remote router that has been enabled to transmit and receive Layer 2 packets.
imposed label stack	Summary of the MPLS label stack used to direct the VC to the PE router.
Create time	Time when the VC was provisioned.
last status change time	Last time the VC state changed.
Signaling protocol	Type of protocol used to send the MPLS labels. The output also shows the status of the peer router.
MPLS VC labels	Local VC label is a disposition label, which determines the egress interface of an arriving packet from the MPLS backbone. The remote VC label is a disposition VC label of the remote peer router.
Group ID	Local group ID is used to group VCs locally. The remote group ID is used by the peer to group several VCs.
MTU	Maximum transmission unit specified for the local and remote interfaces.
Remote interface description	Interface on the remote router that has been enabled to transmit and receive Layer 2 packets.
Sequencing	Field describes whether sequencing of out-of-order packets is enabled or disabled.
local label	The value of the local label that was check-pointed (sent on the active, received on the standby RP).
PWID	The pseudowire ID used in the data plane to correlate the switching context for the segment mentioned with the MPLS switching context. This data is not for customer use but for Cisco personnel for troubleshooting purposes.
packet totals	Number of packets sent and received. Received packets are those AToM packets received from the MPLS core. Sent packets are those AToM packets sent to the MPLS core. This does not include dropped packets.
byte totals	Number of bytes sent and received from the core-facing interface, including the payload, control word if present, and AToM VC label.
packet drops	Number of dropped packets.

Related Commands

Command	Description
show mpls l2transport summary	Displays summary information about VCs that have been enabled to route AToM Layer 2 packets on a router.

Feature Information for AToM NSF

Table 5 lists the release history for this feature.

Not all commands may be available in your Cisco IOS software release. For release information about a specific command, see the command reference documentation.

Cisco IOS software images are specific to a Cisco IOS software release, a feature set, and a platform. Use Cisco Feature Navigator to find information about platform support and Cisco IOS software image support. Access Cisco Feature Navigator at http://www.cisco.com/go/fn. You must have an account on Cisco.com. If you do not have an account or have forgotten your username or password, click Cancel at the login dialog box and follow the instructions that appear.

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Note Table 5 lists only the Cisco IOS software release that introduced support for a given feature in a given Cisco IOS software release train. Unless noted otherwise, subsequent releases of that Cisco IOS software release train also support that feature.

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Table 5 Feature Information for AToM NSF 

Feature Name	Releases	Feature Information
AToM NSF	12.2(25)S 12.2(28)SB	This feature uses NSF, SSO, and Graceful Restart to allow a route processor to recover from a disruption in control plane service without losing its MPLS forwarding state. In 12.2(25)S, this feature was introduced on the Cisco 7500 series router. In 12.2(28)SB, this feature was integrated into the release. The following sections provide information about this feature: •Information About AToM NSF •How to Configure AToM NSF

Any Internet Protocol (IP) addresses used in this document are not intended to be actual addresses. Any examples, command display output, and figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses in illustrative content is unintentional and coincidental.

© 2006 Cisco Systems, Inc. All rights reserved.