We have two 3750 switches setup on local lan. Switch A is primary switch and has ospf setup on it and is a neighbour to a local MPLS Switch. Switch B has etherchannel to Switch A and default route out is switch A. hsrp on all interfaces has switch A as the primary.
Whats the best method to deploy ospf onto switch B? I've tried adding similar commands as switch A but it screws the routing and everything drops across the ospf link for switch A.
To acheive full redundancy you must connect
Switch A to MPLS switch with OSPF >>>>With this Switch A will have routing table from MPLS switch.
Switch B to MPLS switch with OSPF >>>>With this Swtich B will have routing table from MPLS switch.
Access switches uplinked to both switches (A&B) >>>With this Access switches have link level redundancy.
Run HSRP between Switch A & B for all VLANs >>>With this device level redundancy will be acheived.
Switch A connected to Switch B over a Trunk >>>With this traffic can move between switches.
All possible failure scenarios can be mitigated with this topology except one. Explained below:
Consider Access switch link to Switch A fails. Now Swith B will become HSRP active. At the same time Switch B to MPLS switch link fails. Now Switch B don't have routing table to forward traffic.
Hence to avoid this situation you must enable OSPF between Switch A & B, so that they can also share their routing table.