This article provides information on how to configure LDP Tunneling over RSVP and to verify the LDP and RSVP protocol states.
Note: The article tries to supplement the procedure that is detailed in Tunneling LDP LSPs in RSVP LSPs , with some example configurations.
How to configure LDP tunneling over RSVP and to verify the LDP and RSVP protocol states
This article focuses on capturing router states, based on the following topology:
CE8-------R8------R1--------R6--------R2----------R9--------CE9
CE8 and CE9 are CE devices.
R8 and R9 are PE devices.
R1, R2, and R6 are P devices.
Configuration of CE routers :
CE8 :
user@m7i-1-re0# show logical-systems ce8 | no-more interfaces { ge-0/3/1 { unit 104 { description " <-- r8"; vlan-id 104; family inet { address 192.168.1.18/30; } } } lo0 { unit 104 { family inet { address 172.16.1.5/32; } } } } routing-options { static { route 0.0.0.0/0 next-hop 192.168.1.17; } }
CE9 :
user@m7i-1-re0# show logical-systems ce9 | no-more interfaces { ge-0/3/1 { unit 105 { description " <--r9"; vlan-id 105; family inet { address 192.168.1.22/30; } } } lo0 { unit 105 { family inet { address 172.16.1.6/32; } } } } routing-options { static { route 0.0.0.0/0 next-hop 192.168.1.21; } }
Configuration of PE routers : R8 :
user@m7i-1-re0# show logical-systems r8 | no-more interfaces { fe-0/2/0 { unit 200 { description " <-- r1"; vlan-id 200; family inet { address 10.100.0.14/30; } family mpls; } } ge-0/3/0 { unit 104 { description <--ce8; vlan-id 104; family inet { address 192.168.1.17/30; } } } lo0 { unit 8 { family inet { address 10.0.7.8/32; } } } } protocols { mpls { interface fe-0/2/0.200; } bgp { group iBGP { type internal; local-address 10.0.7.8; family inet-vpn { unicast; } neighbor 10.0.7.9; } } ospf { traffic-engineering; area 0.0.0.0 { interface fe-0/2/0.200 { interface-type p2p; } interface lo0.8; } } ldp { interface fe-0/2/0.200; } } routing-instances { 3vpn-3 { instance-type vrf; interface ge-0/3/0.104; vrf-target target:700:3; routing-options { static { route 172.16.1.5/32 next-hop 192.168.1.18; } } } } routing-options { route-distinguisher-id 10.0.7.8; autonomous-system 700; }
R9 :
user@m7i-1-re0# show logical-systems r9 | no-more interfaces { fe-0/2/0 { unit 201 { description " <-- r2"; vlan-id 201; family inet { address 10.100.0.18/30; } family mpls; } } ge-0/3/0 { unit 105 { description to-ce9; vlan-id 105; family inet { address 192.168.1.21/30; } } } lo0 { unit 9 { family inet { address 10.0.7.9/32; } } } } protocols { mpls { interface fe-0/2/0.201; } bgp { group iBGP { type internal; local-address 10.0.7.9; family inet-vpn { unicast; } neighbor 10.0.7.8; } } ospf { traffic-engineering; area 0.0.0.0 { interface fe-0/2/0.201 { interface-type p2p; } interface lo0.9; } } ldp { interface fe-0/2/0.201; } } routing-instances { 3vpn-3 { instance-type vrf; interface ge-0/3/0.105; vrf-target target:700:3; routing-options { static { route 172.16.1.6/32 next-hop 192.168.1.22; } } } } routing-options { route-distinguisher-id 10.0.7.9; autonomous-system 700; }
Configuration of P routers R1 :
user@m7i-1-re0# show logical-systems r1 | no-more interfaces { fe-0/0/3 { unit 200 { description " <-- r8"; vlan-id 200; family inet { address 10.100.0.13/30; } family mpls; } } fe-1/0/0 { unit 16 { description " <-- r6"; vlan-id 16; family inet { address 10.100.8.18/30; } family mpls; } } lo0 { unit 1 { family inet { address 10.0.7.1/32; } } } } protocols { rsvp { interface fe-1/0/0.16; interface fe-0/0/3.200; } mpls { label-switched-path to-r2 { to 10.0.7.2; ldp-tunneling; } interface fe-1/0/0.16; interface fe-0/0/3.200; } ospf { traffic-engineering; area 0.0.0.0 { interface lo0.1; interface fe-1/0/0.16 { interface-type p2p; } interface fe-0/0/3.200 { interface-type p2p; } } } ldp { interface fe-0/0/3.200; interface lo0.1; } } routing-options { autonomous-system 700; }
R2 :
user@m7i-1-re0# show logical-systems r2 | no-more interfaces { fe-0/0/3 { unit 201 { description " <-- r9"; vlan-id 201; family inet { address 10.100.0.17/30; } family mpls; } } fe-1/0/0 { unit 62 { description " <-- r6"; vlan-id 62; family inet { address 10.100.8.5/30; } family mpls; } } lo0 { unit 2 { family inet { address 10.0.7.2/32; } } } } protocols { rsvp { interface fe-1/0/0.62; interface fe-0/0/3.201; } mpls { label-switched-path to-r1 { to 10.0.7.1; ldp-tunneling; } interface fe-1/0/0.62; interface fe-0/0/3.201; } ospf { traffic-engineering; area 0.0.0.0 { interface fe-1/0/0.62 { interface-type p2p; } interface lo0.2; interface fe-0/0/3.201 { interface-type p2p; } } } ldp { interface fe-0/0/3.201; interface lo0.2; } } routing-options { autonomous-system 700; }
R6 :
user@m7i-1-re0# show logical-systems r6 | no-more interfaces { fe-1/0/1 { unit 16 { description " <-- r1"; vlan-id 16; family inet { address 10.100.8.17/30; } family mpls; } unit 62 { description " <-- r2"; vlan-id 62; family inet { address 10.100.8.6/30; } family mpls; } } lo0 { unit 6 { family inet { address 10.0.7.6/3; } } } } protocols { rsvp { interface fe-1/0/1.16; interface fe-1/0/1.62; } mpls { interface fe-1/0/1.16; interface fe-1/0/1.62; } ospf { traffic-engineering; area 0.0.0.0 { interface fe-1/0/1.16 { interface-type p2p; } interface lo0.6; interface fe-1/0/1.62 { interface-type p2p; } } } } routing-options { autonomous-system 700; }
Command Outputs - Verifying if the LDP over RSVP Session is working : When capturing the LDP Session States on P devices, the LDP Session that is established is not direct. On the R1 router, the LDP neighborship is formed over the RSVP tunnel. This is identified by verifying if the Neighbor Type state is configured-tunneled. Neighbor types : Discovered suggest that the routers are directly connected. The Local and Remote addresses indicate that the peering is between the two neighboring routers. In this case, it is R1 and R2, which are connected via R6.
user@router-re0> show ldp session logical-system r1 extensive Address: 10.0.7.2, State: Operational, Connection: Open, Hold time: 21 Session ID: 10.0.7.1:0--10.0.7.2:0 Next keepalive in 1 seconds Passive, Maximum PDU: 4096, Hold time: 30, Neighbor count: 1 Neighbor types: configured-tunneled Keepalive interval: 10, Connect retry interval: 1 Local address: 10.0.7.1, Remote address: 10.0.7.2 Up for 1w5d 01:11:28 Capabilities advertised: none Capabilities received: none Protection: disabled Local - Restart: disabled, Helper mode: enabled Remote - Restart: disabled, Helper mode: enabled Local maximum neighbor reconnect time: 120000 msec Local maximum neighbor recovery time: 240000 msec Nonstop routing state: Not in sync Next-hop addresses received: 10.0.7.2 10.100.0.17 Queue depth: 0
The following output is for the directly connected PE neighbor (the R8 router); check if the Neighbor Type for this device is identified as discovered. R8 connects to R1:
Address: 10.0.7.8, State: Operational, Connection: Open, Hold time: 25 Session ID: 10.0.7.1:0--10.0.7.8:0 Next keepalive in 1 seconds Passive, Maximum PDU: 4096, Hold time: 30, Neighbor count: 1 Neighbor types: discovered Keepalive interval: 10, Connect retry interval: 1 Local address: 10.0.7.1, Remote address: 10.0.7.8 Up for 1w5d 01:12:08 Capabilities advertised: none Capabilities received: none Protection: disabled Local - Restart: disabled, Helper mode: enabled Remote - Restart: disabled, Helper mode: enabled Local maximum neighbor reconnect time: 120000 msec Local maximum neighbor recovery time: 240000 msec Nonstop routing state: Not in sync Next-hop addresses received: 10.100.0.14 Queue depth: 0
These states will help you to identify the difference between the Tunneled LDP and Directly connected LDP neighbors. The states can be further verified in the following output:
user@router-re0> show ldp neighbor logical-system r1 extensive Address Interface Label space ID Hold time 10.100.0.14 fe-0/0/3.200 10.0.7.8:0 12 Transport address: 10.0.7.8, Configuration sequence: 7 Up for 1w5d 01:19:27 Reference count: 1 Hold time: 15, Proposed local/peer: 15/15 Hello flags: none Neighbor types: discovered Address Interface Label space ID Hold time 10.0.7.2 lo0.1 10.0.7.2:0 38 Transport address: 10.0.7.2, Configuration sequence: 3 Up for 1w5d 01:18:34 Reference count: 2 Hold time: 45, Proposed local/peer: 45/45 Hello interval: 15 Hello flags: targeted, request send targeted Neighbor types: configured-tunneled
Verify if the weather label is being advertised for the remote PE router (R9) loopback. Check the LDP databases on the R8 router:
user@router-m7i-re0> show ldp database logical-system r8 Input label database, 10.0.7.8:0--10.0.7.1:0 Label Prefix 3 10.0.7.1/32 299792 10.0.7.2/32 299776 10.0.7.8/32 299808 10.0.7.9/32 Output label database, 10.0.7.8:0--10.0.7.1:0 Label Prefix 300032 10.0.7.1/32 300048 10.0.7.2/32 3 10.0.7.8/32 300064 10.0.7.9/32
The following sample trace was performed on the R8 router to the R9 router. The RSVP-TE hop identifies that LDP traffic is being tunneled over RSVP:
user@router-m7i-re0> traceroute mpls ldp 10.0.7.9 logical-system r8 Probe options: ttl 64, retries 3, wait 10, paths 16, exp 7, fanout 16 ttl Label Protocol Address Previous Hop Probe Status 1 299808 LDP 10.100.0.13 (null) Success 2 299776 RSVP-TE 10.100.8.17 10.100.0.13 Non-compliant 3 10.0.7.9 10.100.8.17 Egress Path 1 via fe-0/2/0.200 destination 127.0.0.64
Corrected the naming of the device on the topology mentioned.
Earlier, R9 is marked as P device, which is incorrect.
R8 and R9 are PE devices, R1, R6 and R2 are P devices (which is correct)