LDP session not coming up

[mail.gajender]

Hi,

I am trying to build ldp neighbor relationship between two routers connected via switch. Both the routers have /31 ip address. The ldp neighbor relationship is not coming up.

===================

Rack1R21#sh run int e0/0.13
Building configuration...

Current configuration : 103 bytes
!
interface Ethernet0/0.13
 encapsulation dot1Q 902
 ip address 10.0.0.2 255.255.255.254
 mpls ip
end

Rack1R21#

Rack1R21#sh mpls ldp discovery
 Local LDP Identifier:
    10.1.1.21:0
    Discovery Sources:
    Interfaces:
        Ethernet0/0.12 (ldp): xmit
        Ethernet0/0.13 (ldp): xmit
        Ethernet0/0.14 (ldp): xmit
Rack1R21#
Rack1R21#

Rack1R21#sh mpls inter
Interface              IP            Tunnel   BGP Static Operational
Ethernet0/0.12         Yes (ldp)     No       No  No     Yes
Ethernet0/0.13         Yes (ldp)     No       No  No     Yes
Ethernet0/0.14         Yes (ldp)     No       No  No     Yes
Rack1R21#
Rack1R21#
Rack1R21#

Rack1R21#ping 10.1.1.23 sou lo0
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.1.1.23, timeout is 2 seconds:
Packet sent with a source address of 10.1.1.21
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms
Rack1R21#

===================================

Rack1R23#sh run int e0/0.13
Building configuration...

Current configuration : 94 bytes
!
interface Ethernet0/0.13
 encapsulation dot1Q 902
 ip address 10.0.0.3 255.255.255.254
end

Rack1R23#
Rack1R23#

Rack1R23#sh mpls ldp discovery
 Local LDP Identifier:
    10.1.1.23:0
    Discovery Sources:
    Interfaces:
        Ethernet0/0 (ldp): xmit
        Ethernet0/0.13 (ldp): xmit
        Ethernet0/0.35 (ldp): xmit
Rack1R23#
Rack1R23#

Rack1R23#
Rack1R23#ping 10.1.1.21 sou lo0
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 10.1.1.21, timeout is 2 seconds:
Packet sent with a source address of 10.1.1.23
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/1 ms
Rack1R23#

Rack1R23#sh mpls inter
Interface              IP            Tunnel   BGP Static Operational
Ethernet0/0            Yes (ldp)     No       No  No     Yes
Ethernet0/0.13         Yes (ldp)     No       No  No     Yes
Ethernet0/0.35         Yes (ldp)     No       No  No     Yes
Rack1R23#
Rack1R23#
Rack1R23#

======================================

There is no output in debup of ldp. Looks like ldp messages are getting initialized. Both the routers are connected via switch and there is no filtering of UDP messages anywhere.Please suggest.

[hdussa]

try /30 Mask on your sub-interface. 

[mail.gajender]

Tried doing that but to no avail. So the problem is not with /31 address. I am able to ping 224.0.0.2. Have fully functional ospf neighbor relationship between them. But in following output i can see interface is only transmitting the ldp packets but not receiving them

Rack1R23#sh mpls ldp discovery
 Local LDP Identifier:
    10.1.1.23:0
    Discovery Sources:
    Interfaces:
        Ethernet0/0.13 (ldp): xmit
        Ethernet0/0.35 (ldp): xmit
Rack1R23#

I am able to ping the ldp router-id from both the routers as well.

[Evgeniy Prichinin]

try to ping 224.0.0.2 (multicast address) and check output.

[mail.gajender]

I am able to ping from both sides.

Rack1R21#ping 224.0.0.2

Type escape sequence to abort.
Sending 1, 100-byte ICMP Echos to 224.0.0.2, timeout is 2 seconds:

Reply to request 0 from 10.0.0.3, 1 ms

Rack1R21#ping 224.0.0.2
Type escape sequence to abort.
Sending 1, 100-byte ICMP Echos to 224.0.0.2, timeout is 2 seconds:

Reply to request 0 from 10.0.0.3, 1 ms
Rack1R21#
Rack1R21#

========================================
Rack1R23#ping 224.0.0.2
Type escape sequence to abort.
Sending 1, 100-byte ICMP Echos to 224.0.0.2, timeout is 2 seconds:

Reply to request 0 from 10.0.0.2, 1 ms
Rack1R23#

Sharing the complete configuration of both the routers.