Working with a client that has a 3750 connected to a Metro-E to link up to their remote branches. The 3750 has a L3 port interface connecting to the Metro-E. Their provider is pulling a 2nd fiber (from a separate CO, different fiber path) to give them additional WAN redundancy. I see that they have two options to connect:
1) Pull into another port on the same 3750 stack (this is their Core). Move the L3 ip address to an SVI, put both ports in the same VLAN and let Spanning tree block one of them. Simple, fairly quick failover ...
2) Pull the 2nd link into another stack, add L3 SVI interfaces to the 2nd stack for all the internal VLANs and a L3 switchport for the Metro-E. Then use HSRP. Less simple (have to create a second core, add HSRP, ...) but keeps STP out of the picture.
My experience with Metro-E is that the whole Metro -E cloud behaves like one big L2 device that just passes along anything you feed it, their devices would not participate in my spannng tree calcs, my BPDUs are contained within my EVC and it is up to me to manage that.
The etherchannel would be great but 1) the last provider I worked with didn't support aggregated links and 2) in this case the carrier's links will terminate at two geographicaly separate locations on their cloud so my guess is that it wouldn't be an option.
I may just use L3 and a routing protocol to use both links.
[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...