I saw a similar scenario once before. The customer had a Metro Ethernet connection from the SP. The default route next hop was set the the FE interface, not the next hop address. The ARP table would populate with all the destinations being on the Internet and destroy the router (1721). This *may* be due to proxy-arp being enabled by default on the older code running on the platform. I changed the default to the next hop IP and it resolved the problem.
[toc:faq]The ProblemOn traditional switches whenever we have a trunk
interface we use the VLAN tag to demultiplex the VLANs. The switch needs
to determine which MAC Address table to look in for a forwarding
decision. To do this we require the switch to do...
[toc:faq]Introduction:Netdr is a tool available on a RSP720, Sup720 or
Sup32 that allows one to capture packets on the RP or SP inband. The
netdr command can be used to capture both Tx and Rx packets in the
software switching path. This is not a substitut...
IntroductionOSPF, being a link-state protocol, allows for every router
in the network to know of every link and OSPF speaker in the entire
network. From this picture each router independently runs the Shortest
Path First (SPF) algorithm to determine the b...