I have a Cisco 3560 switch with sfp uplink to distribution switch. I noticed that the uplink port (dot1q trunk) was flashing amber then green then amber then green. I watched it do this for a good 10 minutes then the link just went dead. I checked the port and it didnt err-disable, it was just down down.
Has anyone experienced something like this or does anyone know what might cause a problem like this.
SFPs are a funny lot. Make sure that it's inserted properly. Unfortunately, it was not designed to "click" if done right therefor you don't know whether or not the link didn't work because the module wasn't inserted properly.
A few days ago, I connected a SFP from a 2960 to a 3750. The 2960's SFP LED is green but the 3750 is not lit. It only started to work when I pulled the SFP in the 3750 out and pushed it in and exerted a little hard until the light went on.
[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...