I have a rogue DHCP machine and have used Windows "dhcploc" tool - along with Ethereal - to track down both the ip address and mac-address of this rogue device. After obtaining both of these, I went to my switch (Cisco 2950) and ran "show mac-address-table" to find where the mac-address was physically plugged into the switch. The results do not show it to be on any FastEthernet port but rather on my Gigabit port. Even more oddly is, unlike all the other listings which show the ports as either FA0/1 or Gi0/1, this particular one is showing only "Gi0/". How do I find this device when it shows on my fiber port? I've traced everywhere I can think of. Thanks, Lu
[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...