CRLSP backup configuration example
Network requirements
Switch A, Switch B, Switch C, and Switch D run IS-IS and IS-IS TE.
Use RSVP-TE to establish an MPLS TE tunnel from Switch A to Switch C to transmit data between the two IP networks. Enable CRLSP hot backup for the tunnel to simultaneously establish a primary CRLSP and a backup CRLSP. When the primary CRLSP fails, traffic is switched to the backup CRLSP.
Figure 34: Network diagram
Table 6: Interface and IP address assignment
Device | Interface | IP address | Device | Interface | IP address |
---|---|---|---|---|---|
Switch A | Loop0 | 1.1.1.9/32 | Switch D | Loop0 | 4.4.4.9/32 |
Vlan-int1 | 10.1.1.1/24 | Vlan-int4 | 30.1.1.2/24 | ||
Vlan-int4 | 30.1.1.1/24 | Vlan-int3 | 40.1.1.1/24 | ||
Vlan-int10 | 100.1.1.1/24 | Switch C | Loop0 | 3.3.3.9/32 | |
Switch B | Loop0 | 2.2.2.9/32 | Vlan-int2 | 20.1.1.2/24 | |
Vlan-int1 | 10.1.1.2/24 | Vlan-int3 | 40.1.1.2/24 | ||
Vlan-int2 | 20.1.1.1/24 | Vlan-int10 | 100.1.2.1/24 |
Configuration procedure
Before configuration, disable the spanning tree feature globally or map each VLAN to an MSTI. For more information, see Layer 2—LAN Switching Configuration Guide.
Configure IP addresses and masks for interfaces. (Details not shown.)
Configure IS-IS to advertise interface addresses, including the loopback interface address, and configure IS-IS TE. (Details not shown.)
Configure an LSR ID, and enable MPLS, MPLS TE, and RSVP-TE:
# Configure Switch A.
<SwitchA> system-view [SwitchA] mpls lsr-id 1.1.1.9 [SwitchA] mpls te [SwitchA-te] quit [SwitchA] rsvp [SwitchA-rsvp] quit [SwitchA] interface vlan-interface 1 [SwitchA-Vlan-interface1] mpls enable [SwitchA-Vlan-interface1] mpls te enable [SwitchA-Vlan-interface1] rsvp enable [SwitchA-Vlan-interface1] quit [SwitchA] interface vlan-interface 4 [SwitchA-Vlan-interface4] mpls enable [SwitchA-Vlan-interface4] mpls te enable [SwitchA-Vlan-interface4] rsvp enable [SwitchA-Vlan-interface4] quit
# Configure Switch B, Switch C, and Switch D in the same way that Switch A is configured. (Details not shown.)
Configure an MPLS TE tunnel on Switch A:
# Configure MPLS TE tunnel interface Tunnel 3.
[SwitchA] interface tunnel 3 mode mpls-te [SwitchA-Tunnel3] ip address 9.1.1.1 24
# Specify the tunnel destination address as the LSR ID of Switch C.
[SwitchA-Tunnel3] destination 3.3.3.9
# Configure MPLS TE to use RSVP-TE to establish the tunnel.
[SwitchA-Tunnel3] mpls te signaling rsvp-te
# Enable CRLSP hot backup for the tunnel.
[SwitchA-Tunnel3] mpls te backup hot-standby [SwitchA-Tunnel3] quit
Configure a static route on Switch A to direct the traffic destined for subnet 100.1.2.0/24 to MPLS TE tunnel 3.
[SwitchA] ip route-static 100.1.2.0 24 tunnel 3 preference 1
Verifying the configuration
# Verify that the tunnel interface Tunnel 3 is up on Switch A.
[SwitchA] display interface tunnel Tunnel3 Current state: UP Line protocol state: UP Description: Tunnel3 Interface Bandwidth: 64kbps Maximum transmission unit: 1496 Internet address: 9.1.1.1/24 (primary) Tunnel source unknown, destination 3.3.3.9 Tunnel TTL 255 Tunnel protocol/transport CR_LSP Output queue - Urgent queuing: Size/Length/Discards 0/100/0 Output queue - Protocol queuing: Size/Length/Discards 0/500/0 Output queue - FIFO queuing: Size/Length/Discards 0/75/0 Last clearing of counters: Never Last 300 seconds input rate: 0 bytes/sec, 0 bits/sec, 0 packets/sec Last 300 seconds output rate: 0 bytes/sec, 0 bits/sec, 0 packets/sec Input: 0 packets, 0 bytes, 0 drops Output: 0 packets, 0 bytes, 0 drops
# Verify that two CRLSPs exist on Switch A, one with the output interface VLAN-interface 1 and the other with the output interface VLAN-interface 4.
[SwitchA] display mpls lsp FEC Proto In/Out Label Interface/Out NHLFE 1.1.1.9/3/34311 RSVP -/1150 Vlan1 1.1.1.9/3/34312 RSVP -/1151 Vlan4 10.1.1.2 Local -/- Vlan1 30.1.1.2 Local -/- Vlan4 Tunnel3 Local -/- NHLFE1026 Backup -/- NHLFE1028
# Display the paths used by the two CRLSPs on Switch A.
[SwitchA] display rsvp lsp verbose Tunnel name: SwitchA_t3 Destination: 3.3.3.9 Source: 1.1.1.9 Tunnel ID: 3 LSP ID: 30106 LSR type: Ingress Direction: Unidirectional Setup priority: 7 Holding priority: 7 In-Label: - Out-Label: 1137 In-Interface: - Out-Interface: Vlan1 Nexthop: 10.1.1.2 Exclude-any: 0 Include-Any: 0 Include-all: 0 Mean rate (CIR): 0 kbps Mean burst size (CBS): 1000.00 bytes Path MTU: 1500 Class type: CT0 RRO number: 6 10.1.1.1/32 Flag: 0x00 (No FRR) 10.1.1.2/32 Flag: 0x00 (No FRR/In-Int) 2.2.2.9/32 Flag: 0x20 (No FRR/Node-ID) 20.1.1.1/32 Flag: 0x00 (No FRR) 20.1.1.2/32 Flag: 0x00 (No FRR/In-Int) 3.3.3.9/32 Flag: 0x20 (No FRR/Node-ID) Fast Reroute protection: None Tunnel name: Tunnel3 Destination: 3.3.3.9 Source: 1.1.1.9 Tunnel ID: 3 LSP ID: 30107 LSR type: Ingress Direction: Unidirectional Setup priority: 7 Holding priority: 7 In-Label: - Out-Label: 1150 In-Interface: - Out-Interface: Vlan4 Nexthop: 30.1.1.2 Exclude-any: 0 Include-Any: 0 Include-all: 0 Mean rate (CIR): 0 kbps Mean burst size (CBS): 1000.00 bytes Path MTU: 1500 Class type: CT0 RRO number: 6 30.1.1.1/32 Flag: 0x00 (No FRR) 30.1.1.2/32 Flag: 0x00 (No FRR/In-Int) 4.4.4.9/32 Flag: 0x20 (No FRR/Node-ID) 40.1.1.1/32 Flag: 0x00 (No FRR) 40.1.1.2/32 Flag: 0x00 (No FRR/In-Int) 3.3.3.9/32 Flag: 0x20 (No FRR/Node-ID) Fast Reroute protection: None
# Trace the path that MPLS TE tunnel 3 traverses. The output shows that the used CRLSP is the one that traverses Switch B.
[SwitchA] tracert mpls te tunnel 3 MPLS trace route TE tunnel Tunnel3 TTL Replier Time Type Downstream 0 Ingress 10.1.1.2/[1147] 1 10.1.1.2 1 ms Transit 20.1.1.2/[3] 2 20.1.1.2 2 ms Egress
# Shut down interface VLAN-interface 2 on Switch B, and then tracert tunnel 3. The output shows that packets are forwarded on the CRLSP that traverses Switch D.
[SwitchA] tracert mpls te tunnel 3 MPLS trace route TE tunnel Tunnel3 TTL Replier Time Type Downstream 0 Ingress 30.1.1.2/[1148] 1 30.1.1.2 2 ms Transit 40.1.1.2/[3] 2 40.1.1.2 3 ms Egress
# Verify that only one CRLSP exists on Switch A.
[SwitchA] display mpls lsp FEC Proto In/Out Label Interface/Out NHLFE 1.1.1.9/3/34313 RSVP -/1150 Vlan4 30.1.1.2 Local -/- Vlan4 Tunnel3 Local -/- NHLFE1029
# Execute the display ip routing-table command on Switch A. The output shows a static route entry with interface Tunnel 3 as the output interface. (Details not shown.)