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MPLS wrong information Label

Hi

This is my first MPLS lab, I just start learning mpls basic from yesterday, All routers have fully ip reachability and ospf is activated on all routers, now my doubt is if Router 1 want to reach Router 5 loopback interface it should go via R4-->R5. but it has two entry for the route 192.168.5.0. please kindly provide me the information why it has wrong entry about 5.0 route.

R5 label range 500-599 <> R4 label range 400-499 <> R1 label range 100 199 <> R6 label range 600 699

R1#sh mpls ldp bindings 192.168.0.5 32
  tib entry: 192.168.0.5/32, rev 18
        local binding:  tag: 105
        remote binding: tsr: 192.168.0.4:0, tag: 401
        remote binding: tsr: 192.168.0.6:0, tag: 605  ---->>
This the wrong information R1 have in  ldp database. 

 

 

 

 

 

 

 

----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

 

R5#sh mpls ldp bind
  tib entry: 172.16.25.0/24, rev 4
        local binding:  tag: imp-null
        remote binding: tsr: 192.168.0.4:0, tag: 400
  tib entry: 172.16.69.0/24, rev 14
        local binding:  tag: 503
        remote binding: tsr: 192.168.0.4:0, tag: 403
  tib entry: 192.168.0.1/32, rev 16
        local binding:  tag: 504
        remote binding: tsr: 192.168.0.4:0, tag: 404
  tib entry: 192.168.0.4/32, rev 8
        local binding:  tag: 500
        remote binding: tsr: 192.168.0.4:0, tag: imp-null
  tib entry: 192.168.0.5/32, rev 6
        local binding:  tag: imp-null
        remote binding: tsr: 192.168.0.4:0, tag: 401
  tib entry: 192.168.0.6/32, rev 18
        local binding:  tag: 505
        remote binding: tsr: 192.168.0.4:0, tag: 405
  tib entry: 192.168.14.0/24, rev 10
        local binding:  tag: 501
        remote binding: tsr: 192.168.0.4:0, tag: imp-null
  tib entry: 192.168.16.0/24, rev 12
        local binding:  tag: 502
        remote binding: tsr: 192.168.0.4:0, tag: 402
  tib entry: 192.168.45.0/24, rev 2
        local binding:  tag: imp-null
        remote binding: tsr: 192.168.0.4:0, tag: imp-null
R5#

R1#sh ip cef 192.168.0.5 255.255.255.255
192.168.0.5/32, version 25, epoch 0, cached adjacency 192.168.14.4
0 packets, 0 bytes
  tag information set
    local tag: 105
    fast tag rewrite with Fa0/0, 192.168.14.4, tags imposed: {401}
  via 192.168.14.4, FastEthernet0/0, 0 dependencies
    next hop 192.168.14.4, FastEthernet0/0
    valid cached adjacency
    tag rewrite with Fa0/0, 192.168.14.4, tags imposed: {401}
R1#

----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

R4#sh mpls ldp bind
  tib entry: 172.16.25.0/24, rev 8
        local binding:  tag: 400
        remote binding: tsr: 192.168.0.5:0, tag: imp-null
        remote binding: tsr: 192.168.0.1:0, tag: 103
  tib entry: 172.16.69.0/24, rev 14
        local binding:  tag: 403
        remote binding: tsr: 192.168.0.1:0, tag: 100
        remote binding: tsr: 192.168.0.5:0, tag: 503
  tib entry: 192.168.0.1/32, rev 16
        local binding:  tag: 404
        remote binding: tsr: 192.168.0.1:0, tag: imp-null
        remote binding: tsr: 192.168.0.5:0, tag: 504
  tib entry: 192.168.0.4/32, rev 6
        local binding:  tag: imp-null
        remote binding: tsr: 192.168.0.5:0, tag: 500
        remote binding: tsr: 192.168.0.1:0, tag: 104
  tib entry: 192.168.0.5/32, rev 10
        local binding:  tag: 401
        remote binding: tsr: 192.168.0.5:0, tag: imp-null
        remote binding: tsr: 192.168.0.1:0, tag: 105
  tib entry: 192.168.0.6/32, rev 18
        local binding:  tag: 405
        remote binding: tsr: 192.168.0.1:0, tag: 101
        remote binding: tsr: 192.168.0.5:0, tag: 505
  tib entry: 192.168.14.0/24, rev 4
        local binding:  tag: imp-null
        remote binding: tsr: 192.168.0.5:0, tag: 501
        remote binding: tsr: 192.168.0.1:0, tag: imp-null
  tib entry: 192.168.16.0/24, rev 12
        local binding:  tag: 402
        remote binding: tsr: 192.168.0.1:0, tag: imp-null
        remote binding: tsr: 192.168.0.5:0, tag: 502
  tib entry: 192.168.45.0/24, rev 5
        local binding:  tag: imp-null
        remote binding: tsr: 192.168.0.5:0, tag: imp-null
        remote binding: tsr: 192.168.0.1:0, tag: 102

 

 

-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

 

R1#sh mpls ldp bi
  tib entry: 172.16.25.0/24, rev 14
        local binding:  tag: 103
        remote binding: tsr: 192.168.0.4:0, tag: 400
        remote binding: tsr: 192.168.0.6:0, tag: 603
  tib entry: 172.16.69.0/24, rev 8
        local binding:  tag: 100
        remote binding: tsr: 192.168.0.6:0, tag: imp-null
        remote binding: tsr: 192.168.0.4:0, tag: 403
  tib entry: 192.168.0.1/32, rev 5
        local binding:  tag: imp-null
        remote binding: tsr: 192.168.0.6:0, tag: 600
        remote binding: tsr: 192.168.0.4:0, tag: 404
  tib entry: 192.168.0.4/32, rev 16
        local binding:  tag: 104
        remote binding: tsr: 192.168.0.4:0, tag: imp-null
        remote binding: tsr: 192.168.0.6:0, tag: 604
  tib entry: 192.168.0.5/32, rev 18
        local binding:  tag: 105
        remote binding: tsr: 192.168.0.4:0, tag: 401
        remote binding: tsr: 192.168.0.6:0, tag: 605
  tib entry: 192.168.0.6/32, rev 10
        local binding:  tag: 101
        remote binding: tsr: 192.168.0.6:0, tag: imp-null
        remote binding: tsr: 192.168.0.4:0, tag: 405
  tib entry: 192.168.14.0/24, rev 4
        local binding:  tag: imp-null
        remote binding: tsr: 192.168.0.6:0, tag: 601
        remote binding: tsr: 192.168.0.4:0, tag: imp-null
  tib entry: 192.168.16.0/24, rev 6
        local binding:  tag: imp-null
        remote binding: tsr: 192.168.0.6:0, tag: imp-null
        remote binding: tsr: 192.168.0.4:0, tag: 402
  tib entry: 192.168.45.0/24, rev 12
        local binding:  tag: 102
        remote binding: tsr: 192.168.0.4:0, tag: imp-null
        remote binding: tsr: 192.168.0.6:0, tag: 602
R1#

 

 

------------------------------------------------------------------------------------------------------------------------------------------------------

R6#sh mpls ldp bind
  tib entry: 172.16.25.0/24, rev 14
        local binding:  tag: 603
        remote binding: tsr: 192.168.0.1:0, tag: 103
  tib entry: 172.16.69.0/24, rev 4
        local binding:  tag: imp-null
        remote binding: tsr: 192.168.0.1:0, tag: 100
  tib entry: 192.168.0.1/32, rev 8
        local binding:  tag: 600
        remote binding: tsr: 192.168.0.1:0, tag: imp-null
  tib entry: 192.168.0.4/32, rev 16
        local binding:  tag: 604
        remote binding: tsr: 192.168.0.1:0, tag: 104
  tib entry: 192.168.0.5/32, rev 18
        local binding:  tag: 605
        remote binding: tsr: 192.168.0.1:0, tag: 105
  tib entry: 192.168.0.6/32, rev 6
        local binding:  tag: imp-null
        remote binding: tsr: 192.168.0.1:0, tag: 101
  tib entry: 192.168.14.0/24, rev 10
        local binding:  tag: 601
        remote binding: tsr: 192.168.0.1:0, tag: imp-null
  tib entry: 192.168.16.0/24, rev 2
        local binding:  tag: imp-null
        remote binding: tsr: 192.168.0.1:0, tag: imp-null
  tib entry: 192.168.45.0/24, rev 12
        local binding:  tag: 602
        remote binding: tsr: 192.168.0.1:0, tag: 102

 

 

 

 

 

 

1 ACCEPTED SOLUTION

Accepted Solutions
Hall of Fame Super Silver

Hello,the show mpls ldp

Hello,

the show mpls ldp binding shows the label to IP prefixes advertisement of every LDP neighbor either upstream (nearest to the prefix) either downstream (more far from the prefix).

The binding via R6 so is a correct binding but it is not used by local node R1 to reach 192.168.0.5/32.

As the sh ip cef shows there is actually a single best path to the destination that is in the direction of R5.

 

R1#sh ip cef 192.168.0.5 255.255.255.255
192.168.0.5/32, version 25, epoch 0, cached adjacency 192.168.14.4
0 packets, 0 bytes
  tag information set
    local tag: 105
    fast tag rewrite with Fa0/0, 192.168.14.4, tags imposed: {401}
  via 192.168.14.4, FastEthernet0/0, 0 dependencies
    next hop 192.168.14.4, FastEthernet0/0
    valid cached adjacency
    tag rewrite with Fa0/0, 192.168.14.4, tags imposed: {401}
R1#

 

So you don't need to care about the additional entries in show mpls ldp binding.

 

Hope to help

Giuseppe

 

 

 

1 REPLY
Hall of Fame Super Silver

Hello,the show mpls ldp

Hello,

the show mpls ldp binding shows the label to IP prefixes advertisement of every LDP neighbor either upstream (nearest to the prefix) either downstream (more far from the prefix).

The binding via R6 so is a correct binding but it is not used by local node R1 to reach 192.168.0.5/32.

As the sh ip cef shows there is actually a single best path to the destination that is in the direction of R5.

 

R1#sh ip cef 192.168.0.5 255.255.255.255
192.168.0.5/32, version 25, epoch 0, cached adjacency 192.168.14.4
0 packets, 0 bytes
  tag information set
    local tag: 105
    fast tag rewrite with Fa0/0, 192.168.14.4, tags imposed: {401}
  via 192.168.14.4, FastEthernet0/0, 0 dependencies
    next hop 192.168.14.4, FastEthernet0/0
    valid cached adjacency
    tag rewrite with Fa0/0, 192.168.14.4, tags imposed: {401}
R1#

 

So you don't need to care about the additional entries in show mpls ldp binding.

 

Hope to help

Giuseppe

 

 

 

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