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 2LAN Switching Configuration Guide.

  1. Configure IP addresses and masks for interfaces. (Details not shown.)

  2. Configure IS-IS to advertise interface addresses, including the loopback interface address, and configure IS-IS TE. (Details not shown.)

  3. 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.)

  4. 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
    
  5. 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.)