Encapsulation failed on Cisco C881 over point-point circuit

[shuklavikas@yahoo.com]

I am installing a router for customer, where I have a P2P circuit connecting one end to the site router other end goes to our core device.

Both the end IP’s are in same Subnet x.x.x.x/30, when I am trying to ping other end IP from the router is says “encapsulation failed”. However, when I connect the same circuit to machine, I am able to ping my hub IP and it works.

Please help ! 

[Georg Pauwen]

Hello,

post the configs of both sides. What is the core device the router is connected to ? Make sure you are using the right cable (cross for router to router)...

[shuklavikas@yahoo.com]

Thanks for your reply Georg, yes I tried using different cables straight and cross both, but in both the cases getting same error

Core device is Juniper, where we have other sites configured and working, site router is Cisco.

Attaching core and site router config

[Georg Pauwen]

Hello,

with directly connected links it shouldn't be necessary, but try and set a static route on the Juniper and the Cisco pointing out their respective interfaces...

[paul driver]

Helllo

not able to see you config file but.  

Both the end IP’s are in same Subnet x.x.x.x/30, when I am trying to ping other end IP from the router is says “encapsulation failed”. However, when I connect the same circuit to machine, I am able to ping my hub IP and it works.

Please help ! 

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From the rtr how are you souricing the ping is it from a subnet the end host is aware of ?

[Richard Burts]

I have these comments about this issue:

- The core sets this up as a vlaned interface which suggests that it will send tagged frames. I believe that the router is not expecting tagged frames on that interface. I wonder what would happen if you move the connection on the router to a different interface and configured that interface to be a member of the vlan specified on the core?

- it looks like you are hardcoding the speed on the core but asking the router to negotiate. That might work but sometimes it causes problems when one device attempts to negotiate and the other device will not negotiate. I suggest that you set up both devices to do the same thing.

- you show us the address used on the router but on the core you show only x.x.x.x so we can not know if the addresses do really match up. A mismatched address or subnet could cause this type of problem.

- encapsulation failed indicates that the router is not able to resolve the layer 3 IP address to an appropriate layer 2 address (in this case a mac address). One thing that might cause this would be some problem with interface status. Would you post the output of show ip interface brief on the router?

HTH

Rick