I've got a Cisco 7200 VXR with a 12.3T IOS. This is what happens: I have a switch with 2 routers (Router A - the 7200 and Router B - one 3620) and one firewall. Router B has a static route to Network C via firewall. When a packet arrives at router B with a destination IP from Network C, router B correctly forwards the packet to the firewall. However when I check the firewall for incoming packets I notice that
two identical packets arrive at the firewall. Both with the same source IP but with different source MAC addresses! The MAC from router B and from router A!
How can router A forward a packet a copy of the packet when router B has a static route via firewall?
Is router A part of Network C? Is there any ships in the night which is forwarding all the traffic from NEtwork C to Router A and router A is routing the traffic to Router B, check for all the details of routing on Router A.
[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...