It is really tough to attempt to troubleshoot problems of this type when you: 1) Did not post any configs of the two routers, or the CAT5K 2) Did not mention what type of routers were involved: RSM, RSFC, or an external router? Notwithstanding all of that, I will attempt to take a semi- educated swag on what *may* be related to the problem. For starters, you are getting an encapsulation failure because you did not get a valid response from your ARP request. If you are using an RSFC, go to the router console and do a "show interface" command and see what the status is reported to be. It should be "up" and "up" for the IBC0 interface. If it is not, you have a fairly expensive problem - you may need a new RSFC. If it is not an RSFC, before you attempt another ping, unplug the router from the switch and verify that no other devices are using the same IP address on that VLAN. Put a sniffer on a port monitored switchport that monitors that VLAN. Do a broadcast ping to the subnet's broadcast address and see who answers the call of the wild... Additionally, I would clear out the arp cache on each router involved and if possible, clear the CAM table on CAT5k before reattempting a ping. Do not do this on an active production network. Wait until after hours to perform this task. Regarding your comment below about the 0000.0000.0000 value in the ARP field, that is an expected value. You are not looking at the layer 2 destination address, you are looking at the logical placeholder for the ARP layer 2 target address field. If a valid ARP reply was returned, you would have an actual MAC address assigned to that field. See this link for further details (watch wrap): http://www.west- point.org/users/usma1983/40768/chesinc/docs/ciscoarp.txt Next, have you in fact verified that the target router has an "up" and "up" condition for an E0 interface for an external router? Is it in fact carried on the same VLAN as the other router? Are they on the same logical IP subnet? In the absence of any configs or some other basic information, that is as good as a swag as I can muster. HTH, Paul Werner > We have 2 routers plugged into the same Vlan on a cat 5500. All layer 2 info seems to be showing up just fine from all devices. The routers have a basic simple config. You know e0 ip addrees/subnet... several people have looked at it and agree all the configs look just fine. > > Here is what happens > > When we ping from one particular router (called it sneezy) to the other (dopey), there is no response. Debug ip packet revelas that sneezy is getting encapsulation failed. (This happens on any other router plugged into that port on the switch so it is not router specific, and they are all using the same ethernet encaps arpa). > > Also, the arp packets from sneezy seemed to be going out as > 0000.0000.0000 instead of ffff.ffff.ffff.ffff > > I am going to simply assume a hardware malfunction on that port of the switch unless someone here has seen a similiar issue and can attribute it to something else???? ________________________________________________ Get your own "800" number Voicemail, fax, email, and a lot more http://www.ureach.com/reg/tag _________________________________ FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
