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| Title | Size | Download |
|---|---|---|
| 10-MPLS OAM configuration | 121.34 KB |
Contents
Configuring MPLS OAM for LSP tunnels
Configuring MPLS ping for LSPs
Configuring MPLS tracert for LSPs
Configuring periodic MPLS tracert for LSPs
Configuring MPLS ping for a PW
Configuring MPLS OAM
Overview
· MPLS data plane connectivity verification.
· Data plane and control plane consistency verification.
· Fault locating.
These fault management tools include the following types:
· On-demand tools—Tools that need to be triggered manually, such as MPLS ping and MPLS tracert.
· Proactive tools—Tools that are triggered by the system automatically, such as periodic MPLS tracert.
You can use these tools to detect and locate faults of LSPs.
MPLS ping
MPLS ping tests the connectivity of an LSP tunnel. At the ingress node, MPLS ping adds the label associated with a tunnel into an MPLS echo request and sends it to the egress node over the tunnel. The egress node processes the request and returns an MPLS echo reply to the ingress node. An MPLS echo reply with a success notification indicates that the tunnel is available for data forwarding, and an MPLS echo reply with an error code indicates that the tunnel has failed.
MPLS tracert
MPLS tracert displays the path that an MPLS LSP tunnel travels from the ingress node to the egress node to locate errors on the tunnel. MPLS tracert consecutively sends MPLS echo requests along the LSP tunnel, with the TTL increasing from 1 to a specific value. Each hop along the tunnel returns an MPLS echo reply to the ingress due to TTL timeout so the ingress can collect information about each hop along the tunnel. This information allows you to locate the failed node or access information for each hop, for example, the label allocated by each downstream hop.
BFD for MPLS
BFD for MPLS uses a BFD session to proactively verify the connectivity of a PW tunnel.
BFD for MPLS does the following:
1. Establishes a BFD session between the ingress and egress of the tunnel to be inspected.
2. Adds the label associated with the tunnel into a BFD control packet at the ingress.
3. Sends the packet to the egress node over the tunnel.
4. Determines the tunnel status according to the BFD control packet returned by the egress.
When BFD detects a connectivity failure, it triggers the pre-configured action, such as FRR or path protection switching, to ensure uninterrupted traffic forwarding.
A BFD session for PW connectivity verification can be established in one of the following modes:
· Static mode—You manually specify the local and remote discriminators through command lines to establish the BFD session.
· Dynamic mode—The system automatically runs MPLS ping to negotiate the discriminators to establish the BFD session.
Periodic MPLS tracert
The periodic MPLS tracert function automatically traces an LSP tunnel at intervals. It locates errors on the LSP tunnel, verifies the consistency of the data plane and control plane, and records the detected errors in system logs. You can check the logs to monitor LSP connectivity.
Protocols and standards
· RFC 4379, Detecting Multi-Protocol Label Switched (MPLS) Data Plane Failures
· RFC 5085, Pseudowire Virtual Circuit Connectivity Verification (VCCV): A Control Channel for Pseudowires
· RFC 5885, Bidirectional Forwarding Detection (BFD) for the Pseudowire Virtual Circuit Connectivity Verification (VCCV)
Configuring MPLS OAM for LSP tunnels
To verify LSP connectivity, you can use one of the following methods:
· Use the ping mpls ipv4 command or the tracert mpls ipv4 command to trigger LSP connectivity verification as needed.
· Configure periodic MPLS tracert for the system to automatically verify LSP connectivity.
Configuring MPLS ping for LSPs
Perform the following task in any view:
|
Task |
Command |
|
Use MPLS ping to verify MPLS LSP connectivity for an IPv4 prefix. |
ping mpls [ -a source-ip | -c count | -exp exp-value | -h ttl-value | -m wait-time | -r reply-mode | -rtos tos-value | -s packet-size | -t time-out | -v ] * ipv4 dest-addr mask-length [ destination start-address [ end-address [ address-increment ] ] ] |
Configuring MPLS tracert for LSPs
Perform the following task in any view:
|
Task |
Command |
|
Use MPLS tracert to trace the LSPs for an IPv4 prefix. |
tracert mpls [ -a source-ip | -exp exp-value | -h ttl-value | -r reply-mode | -rtos tos-value | -t time-out | -v | fec-check ] * ipv4 dest-addr mask-length [ destination start-address [ end-address [ address-increment ] ] ] |
Configuring periodic MPLS tracert for LSPs
|
Step |
Command |
Remarks |
|
1. Enter system view. |
system-view |
N/A |
|
2. Enable periodic LSP tracert for an FEC. |
mpls periodic-tracert dest-addr mask-length [ -a source-ip | -exp exp-value | -h ttl-value | -m wait-time | -rtos tos-value | -t time-out | -u retry-attempt | fec-check ] * |
By default, periodic LSP tracert is disabled. |
Configuring MPLS OAM for a PW
Virtual Circuit Connectivity Verification (VCCV) is an L2VPN PW OAM function to verify PW connectivity in data plane. VCCV can be implemented in the following modes:
· On-demand mode—Execute the ping mpls pw command to trigger PW connectivity detection.
· Proactive mode—Configure BFD for a PW to test PW connectivity.
The packets used to verify PW connectivity are collectively referred to as VCCV packets. A PE transfers VCCV packets through a control channel (CC).
The VCCV CC type router-alert identifies a VCCV packet by adding an MPLS router alert label before the PW label.
Connectivity Verification (CV) tools include the following types:
· MPLS ping—Uses MPLS ping to verify PW connectivity.
· BFD—Uses BFD to verify PW connectivity. BFD packets use IP/UDP encapsulation (with IP/UDP headers).
Configuring MPLS ping for a PW
Before you configure MPLS ping for a PW, perform the following tasks:
1. Create a PW class, and use the vccv cc command to configure the VCCV CC type in PW class view.
2. Create the PW, and reference the PW class created in the previous step for the PW.
Perform the following task in any view:
|
Task |
Command |
|
Use MPLS ping to verify the connectivity of a PW. |
ping mpls [ -a source-ip | -c count | -exp exp-value | -h ttl-value | -m wait-time | -r reply-mode | -rtos tos-value | -s packet-size | -t time-out | -v ] * pw ip-address pw-id pw-id |
Configuring BFD for a PW
Follow these steps to configure BFD for a PW:
1. Enable BFD for MPLS.
2. Create a PW class, and configure BFD for PW connectivity verification in PW class view.
3. Create the PW, and reference the PW class created in the previous step for the PW.
If both PEs of the PW have configured BFD and use the same BFD packet encapsulation type, the PEs use the specified encapsulation type to verify PW connectivity. Otherwise, the PEs do not use BFD to verify PW connectivity.
If both PEs have specified the same VCCV CC type, the specified VCCV CC type is used. Otherwise, the PEs do not use any CC and they cannot establish a BFD session for the PW.
Configuring BFD for an MPLS L2VPN PW
Perform this task to use BFD to verify the connectivity of a static PW or an LDP PW of MPLS L2VPN:
|
Step |
Command |
Remarks |
|
1. Enter system view. |
system-view |
N/A |
|
2. Enable BFD for MPLS. |
mpls bfd enable |
By default, BFD for MPLS is disabled. |
|
3. Create a PW class and enter PW class view. |
pw-class class-name |
By default, no PW class is created. To use BFD to verify connectivity of a PW, you must create a PW class for the PW and configure VCCV settings in PW class view. |
|
4. Use BFD to verify PW connectivity. |
vccv bfd [ template template-name ] |
By default, BFD is not used to verify PW connectivity. The template template-name option is not supported in the current software version. |
|
5. Specify the VCCV CC type. |
vccv cc router-alert |
By default, no VCCV CC type is specified. |
|
6. Return to system view. |
quit |
N/A |
|
7. Enter cross-connect group view. |
xconnect-group group-name |
N/A |
|
8. Enter cross-connect view. |
connection connection-name |
N/A |
|
9. Configure a PW, specify the created PW class for it, and enter PW view. |
peer ip-address pw-id pw-id [ in-label label-value out-label label-value ] [ pw-class class-name | tunnel-policy tunnel-policy-name ] * |
By default, no PW is configured. |
|
10. (Optional.) Set the local and remote discriminators for the BFD session used to verify PW connectivity. |
bfd discriminator local local-id remote remote-id |
By default, no local and remote discriminators are set. Make sure the local discriminator and remote discriminator configured on the local PE are the same as the remote discriminator and local discriminator configured on the remote PE, respectively. |
|
11. (Optional.) Configure a backup PW, specify the PW class for the backup PW, and enter backup PW view. |
backup-peer ip-address pw-id pw-id [ in-label label-value out-label label-value ] [ pw-class class-name | tunnel-policy tunnel-policy-name ] * |
By default, no backup PW is configured. |
|
12. (Optional.) Set the local and remote discriminators for the BFD session used to verify the connectivity of the backup PW. |
bfd discriminator local local-id remote remote-id |
By default, no local and remote discriminators are set. Make sure the local discriminator and remote discriminator configured on the local PE are the same as the remote discriminator and local discriminator configured on the remote PE, respectively. |
Configuring BFD for a VPLS static PW
|
Step |
Command |
Remarks |
|
1. Enter system view. |
system-view |
N/A |
|
2. Enable BFD for MPLS. |
mpls bfd enable |
By default, BFD for MPLS is disabled. |
|
3. Create a PW class and enter PW class view. |
pw-class class-name |
By default, no PW class is created. To use BFD to verify connectivity of a PW, you must create a PW class for the PW and configure VCCV settings in PW class view. |
|
4. Use BFD to verify PW connectivity. |
vccv bfd [ template template-name ] |
By default, BFD is not used to verify PW connectivity. The template template-name option is not supported in the current software version. |
|
5. Specify the VCCV CC type. |
vccv cc router-alert |
By default, no VCCV CC type is specified. |
|
6. Return to system view. |
quit |
N/A |
|
7. Enter VSI view. |
vsi vsi-name [ hub-spoke ] |
The hub-spoke keyword is not supported in the current software version. |
|
8. Configure the VSI to establish static PWs and enter VSI static view. |
pwsignaling static |
By default, no PW signaling protocol is specified for a VSI. |
|
9. Configure a VPLS PW, specify the created PW class for it, and enter VSI static PW view. |
peer ip-address [ pw-id pw-id ] [ in-label label-value out-label label-value [ hub | no-split-horizon | pw-class class-name | tunnel-policy tunnel-policy-name ] * ] |
By default, no VPLS PW is configured. |
|
10. (Optional.) Set the local and remote discriminators for the BFD session used to verify PW connectivity. |
bfd discriminator local local-id remote remote-id |
By default, no local and remote discriminators are set. Make sure the local discriminator and remote discriminator configured on the local PE are the same as the remote discriminator and local discriminator configured on the remote PE, respectively. |
|
11. (Optional.) Configure a static backup PW, specify the PW class for the backup PW, and enter VSI static backup PW view. |
backup-peer ip-address [ pw-id pw-id ] in-label label-value out-label label-value [ pw-class class-name | tunnel-policy tunnel-policy-name ] * |
By default, no backup VPLS PW is configured. |
|
12. (Optional.) Set the local and remote discriminators for the BFD session used to verify the connectivity of the backup PW. |
bfd discriminator local local-id remote remote-id |
By default, no local and remote discriminators are set. Make sure the local discriminator and remote discriminator configured on the local PE are the same as the remote discriminator and local discriminator configured on the remote PE, respectively. |
Configuring BFD for a VPLS LDP PW
|
Step |
Command |
Remarks |
|
1. Enter system view. |
system-view |
N/A |
|
2. Enable BFD for MPLS. |
mpls bfd enable |
By default, BFD for MPLS is disabled. |
|
3. Create a PW class and enter PW class view. |
pw-class class-name |
By default, no PW class is created. To use BFD to verify connectivity of a PW, you must create a PW class for the PW and configure VCCV settings in PW class view. |
|
4. Use BFD to verify PW connectivity. |
vccv bfd [ template template-name ] |
By default, BFD is not used to verify PW connectivity. The template template-name option is not supported in the current software version. |
|
5. Specify the VCCV CC type. |
vccv cc router-alert |
By default, no VCCV CC type is specified. |
|
6. Return to system view. |
quit |
N/A |
|
7. Enter VSI view. |
vsi vsi-name [ hub-spoke ] |
The hub-spoke keyword is not supported in the current software version. |
|
8. Configure the VSI to establish PWs using LDP and enter VSI LDP view. |
pwsignaling ldp |
By default, no PW signaling protocol is specified for a VSI. |
|
9. Configure a VPLS PW, specify the created PW class for it, and enter VSI LDP PW view. |
peer ip-address [ pw-id pw-id ] [ hub | no-split-horizon | pw-class class-name | tunnel-policy tunnel-policy-name ] * |
By default, no VPLS PW is configured. |
|
10. (Optional.) Set the local and remote discriminators for the BFD session used to verify PW connectivity. |
bfd discriminator local local-id remote remote-id |
By default, no local and remote discriminators are set. Make sure the local discriminator and remote discriminator configured on the local PE are the same as the remote discriminator and local discriminator configured on the remote PE, respectively. |
|
11. (Optional.) Configure an LDP backup PW, specify the PW class for the backup PW, and enter VSI LDP backup PW view. |
backup-peer ip-address [ pw-id pw-id ] [ pw-class class-name | tunnel-policy tunnel-policy-name ] * |
By default, no backup VPLS PW is configured. |
|
12. (Optional.) Set the local and remote discriminators for the BFD session used to verify the connectivity of the backup PW. |
bfd discriminator local local-id remote remote-id |
By default, no local and remote discriminators are set. Make sure the local discriminator and remote discriminator configured on the local PE are the same as the remote discriminator and local discriminator configured on the remote PE, respectively. |
Displaying MPLS OAM
Execute display commands in any view.
|
Task |
Command |
|
Display BFD information for PWs. |
display l2vpn pw bfd [ peer peer-ip pw-id pw-id ] |
