TE + FR MP

Guys are you aware about any issues related to TE Tunnels and FR Multipoint interfaces ? Each time i set up TE tunnel on a router and the outgoing interface for the LSP is FR Multipoint the label is not being assigned to the Tunnel. I have seen that behavior on couple different lab scenarios i was working on recently. Maybe there is something specific about FR MP interfaces and TE tunnels i am just missing ?

Here is example. I have back to back FR connection set between R1 and R4, outgoing interface for the tunnel on R1 is S2/1

interface Serial2/1
 bandwidth 45000
 ip address 124.1.13.1 255.255.255.0
 encapsulation frame-relay
 frame-relay interface-dlci 100
 ip ospf network point-to-point
 ip ospf 1 area 0
 mpls traffic-eng tunnels
 ip rsvp bandwidth 15000 5000
end

interface Tunnel14
 ip unnumbered Loopback0
 tunnel destination 124.1.4.4
 tunnel mode mpls traffic-eng
 tunnel mpls traffic-eng autoroute announce
 tunnel mpls traffic-eng priority 7 7
 tunnel mpls traffic-eng bandwidth  2500
 tunnel mpls traffic-eng path-option 10 explicit name R1->R3->R2->R4
 tunnel mpls traffic-eng path-option 20 explicit name R1->R3->R4
 no routing dynamic
end


Debug shows that label 21 is assigned for Tunnel 14

*Aug 31 01:54:52.491: %LINK-3-UPDOWN: Interface Tunnel14, changed state to up
*Aug 31 01:54:53.491: %LINEPROTO-5-UPDOWN: Line protocol on Interface Tunnel14, changed state to up
*Aug 31 01:54:53.571: LSP-TUNNEL-LABELS: tunnel 124.1.1.1 14 [22]: fabric PROGRAM request
*Aug 31 01:54:53.571: LSP-TUNNEL-LABELS: tunnel 124.1.1.1 14 [22]: programming label 21 on output interface Serial2/1


There is no label assigned to this tunnel in forwarding table of R1 (???). However on the next routers in the path R1->R3->R2->R4 i can see the labels for this tunnel assigned just fine.

R1#sh mpls forwarding-table
Local  Outgoing    Prefix            Bytes tag  Outgoing   Next Hop   
tag    tag or VC   or Tunnel Id      switched   interface             
16     Pop tag     124.1.2.2/32      0          AT3/0.12   point2point 
17     Pop tag     124.1.3.3/32      0          Se2/1      124.1.13.3  
18     Untagged[T] 124.1.4.4/32      0          Tu14       point2point 
19     Pop tag     124.1.23.0/24     0          AT3/0.12   point2point 
20     Pop tag     124.1.24.0/24     0          AT3/0.12   point2point 
21     Untagged[T] 124.1.34.0/24     0          Tu14       point2point 
22     Aggregate   64.1.16.0/24[V]   0                                 
23     Pop tag     64.1.6.6/32[V]    7098       Fa1/0      64.1.16.6   
24     Recursive   64.1.5.5/32[V]    0                                 
25     Recursive   64.1.7.7/32[V]    0                                 
26     Recursive   64.1.8.8/32[V]    0                                 
27     Recursive   64.1.45.0/24[V]   0                                 
28     Recursive   64.1.57.0/24[V]   0                                 
29     Recursive   64.1.78.0/24[V]   0               

R1#sh mpls forwarding-table 124.1.4.4 detail
Local  Outgoing    Prefix            Bytes tag  Outgoing   Next Hop   
tag    tag or VC   or Tunnel Id      switched   interface             
18     Untagged    124.1.4.4/32      0          Tu14       point2point 
        MAC/Encaps=0/0, MRU=1500, Tag Stack{}, via Se2/1
        No output feature configured
    Per-packet load-sharing

R1#sh ip cef 124.1.4.4        
124.1.4.4/32, version 20, epoch 0
0 packets, 0 bytes
  tag information set, shared
    local tag: 18
  via 0.0.0.0, Tunnel14, 6 dependencies
    next hop 0.0.0.0, Tunnel14
    invalid adjacency
    tag rewrite with Tu14, point2point, tags imposed: {}


Now, when i change the S2/1 encapsulation to something else (it can be FR P2P subinterface for example or ppp i used here)

interface Serial2/1
 bandwidth 45000
 ip address 124.1.13.1 255.255.255.0
 encapsulation ppp
 ip ospf network point-to-point
 ip ospf 1 area 0
 mpls traffic-eng tunnels
 ip rsvp bandwidth 15000 5000

Everything works just fine !!!

*Aug 31 01:58:12.179: %OSPF-5-ADJCHG: Process 1, Nbr 124.1.3.3 on Serial2/1 from LOADING to FULL, Loading Done
*Aug 31 01:58:12.267: LSP-TUNNEL-LABELS: tunnel 124.1.1.1 14 [43]: fabric PROGRAM request
*Aug 31 01:58:12.267: LSP-TUNNEL-LABELS: tunnel 124.1.1.1 14 [43]: programming label 23 on output interface Serial2/1

R1#sh mpls forwarding-table
Local  Outgoing    Prefix            Bytes tag  Outgoing   Next Hop   
tag    tag or VC   or Tunnel Id      switched   interface             
16     Pop tag     124.1.2.2/32      0          AT3/0.12   point2point 
17     Pop tag     124.1.3.3/32      0          Se2/1      point2point 
18     Pop tag [T] 124.1.4.4/32      0          Tu14       point2point 
19     Pop tag     124.1.23.0/24     0          AT3/0.12   point2point 
20     Pop tag     124.1.24.0/24     0          AT3/0.12   point2point 
21     Untagged[T] 124.1.34.0/24     0          Tu14       point2point 
22     Aggregate   64.1.16.0/24[V]   0                                 
23     Pop tag     64.1.6.6/32[V]    84290      Fa1/0      64.1.16.6   
24     25      [T] 64.1.5.5/32[V]    37288      Tu14       point2point 
25     24      [T] 64.1.7.7/32[V]    0          Tu14       point2point 
26     23      [T] 64.1.8.8/32[V]    0          Tu14       point2point 
27     26      [T] 64.1.45.0/24[V]   0          Tu14       point2point 
28     27      [T] 64.1.57.0/24[V]   0          Tu14       point2point 
29     22      [T] 64.1.78.0/24[V]   0          Tu14       point2point 
31     Untagged    124.1.13.3/32     0          Se2/1      point2point

R1#sh mpls forwarding-table 124.1.4.4 detail
Local  Outgoing    Prefix            Bytes tag  Outgoing   Next Hop   
tag    tag or VC   or Tunnel Id      switched   interface             
18     Pop tag     124.1.4.4/32      0          Tu14       point2point 
        MAC/Encaps=4/8, MRU=1500, Tag Stack{23}, via Se2/1
        FF030281 00017000
        No output feature configured
    Per-packet load-sharing

R1#sh ip cef 124.1.4.4       
124.1.4.4/32, version 42, epoch 0
0 packets, 0 bytes
  tag information set, shared
    local tag: 18
    fast tag rewrite with Tu14, point2point, tags imposed: {23}
  via 0.0.0.0, Tunnel14, 6 dependencies
    next hop 0.0.0.0, Tunnel14
    valid adjacency
    tag rewrite with Tu14, point2point, tags imposed: {23}


Thanks,

Sebastian Majewski

 

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