CRLSP backup configuration example
Network requirements
Switch A, Switch B, Switch C, and Switch D run IS-IS.
Use RSVP-TE to establish an MPLS TE tunnel from Switch A to Switch C. 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 25: Network diagram
Table 3: 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 | ||
Switch B | Loop0 | 2.2.2.9/32 | Switch C | Loop0 | 3.3.3.9/32 |
Vlan-int1 | 10.1.1.2/24 | Vlan-int2 | 20.1.1.2/24 | ||
Vlan-int2 | 20.1.1.1/24 | Vlan-int3 | 40.1.1.2/24 |
Configuration procedure
Configure IP addresses and masks for interfaces. (Details not shown.)
Configure IS-IS to advertise interface addresses, including the loopback interface address. (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 the 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 20.1.1.0/24 to MPLS TE tunnel 3.
[SwitchA] ip route-static 20.1.1.2 24 tunnel 3 preference 1
Verifying the configuration
# Execute the display interface tunnel command on Switch A. The output shows that the tunnel interface Tunnel 3 is up.
[SwitchA] display interface tunnel
Tunnel3 current state: UP
Line protocol current state: UP
Description: Tunnel3 Interface
The Maximum Transmit Unit is 64000
Internet Address is 9.1.1.1/24 Primary
Tunnel source unknown, destination 3.3.3.9
Tunnel bandwidth 64 (kbps)
Tunnel TTL 255
Tunnel protocol/transport CR_LSP
Last clearing of counters: Never
Last 300 seconds input rate: 0 bytes/sec, 0 bits/sec, 0 packets/sec
Last 300 seconds output rate: 1802 bytes/sec, 14416 bits/sec, 0 packets/sec
0 packets input, 0 bytes, 0 drops
351 packets output, 3105652 bytes, 0 drops
# Execute the display mpls lsp command on Switch A. The output shows that two CRLSPs exist on the switch, 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 1.1.1.9/3/30106 RSVP -/1137 Vlan1 1.1.1.9/3/30107 RSVP -/1150 Vlan4 10.1.1.2 Local -/- Vlan1 30.1.1.2 Local -/- Vlan4
# Execute the display rsvp lsp verbose command on Switch A to display the paths used by the two CRLSPs.
[SwitchA] display rsvp lsp verbose
Tunnel name: Tunnel3
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
Average bitrate: 0 kbps Maximum burst: 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)
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)
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
Average bitrate: 0 kbps Maximum burst: 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)
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)
3.3.3.9/32 Flag: 0x20 (No FRR/Node-ID)
Fast Reroute protection: None
# Tracert the tunnel destination 3.3.3.9. The output shows that the currently used CRLSP is the one that traverses Switch B.
[SwitchA] tracert –a 1.1.1.9 3.3.3.9 traceroute to 3.3.3.9 (3.3.3.9) from 1.1.1.9, 30 hops at most, 40 bytes each pac ket, press CTRL_C to break 1 10.1.1.2 (10.1.1.2) 1.000 ms 1.000 ms 1.000 ms 2 * * *
# Shut down interface VLAN-interface 2 on Switch B, and then tracert the tunnel destination. The output shows that packets are forwarded on the CRLSP that traverses Switch D.
[SwitchA] tracert –a 1.1.1.9 3.3.3.9 traceroute to 3.3.3.9 (3.3.3.9) from 9.1.1.1, 30 hops at most, 40 bytes each pac ket, press CTRL_C to break 1 30.1.1.2 (30.1.1.2) 3.000 ms 7.000 ms 3.000 ms 2 * * *
# Execute the display mpls lsp command on Switch A. The output shows that only one CRLSP exists on the switch.
[SwitchA] display mpls lsp FEC Proto In/Out Label Interface/Out NHLFE 1.1.1.9/3/48984 RSVP -/1150 Vlan4 30.1.1.2 Local -/- Vlan4
# 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.