Thanks for the responses. I was really trying to find out if the Serial interface could be up without a cable attached. For instance, "Serial0 line is up, line protocol is down". The only way to have this status is to have a signal into the CSU/DSU itself, correct? I was wondering because the T1 card in my 1721, was status of down/down when 5 minutes before putting the router in, the line was functional with a differenet router. This leads me to believe there is a hardware failure with the T1 card.
Yes, I configured this. But this will not bring the status, to "Serial line is up, line protocol is down". I am pretty sure you need a valid Carrier Detect from the telco via a CAT5 cable to the CSU/DSU to attain this status.
[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...