- Bronze, 100 points or more
Hi fellow experts,
I have some queries regarding some redundancy design, as we're in the midst of swapping 7600 boxes with ASR9K. First of all, is it possible to configure the same vlan encapsulation on two different sub-interfaces belonging to two different physical interfaces (i.e. g0/7/0/0 & g0/7/0/1) of a same linecard (i.e 40x1GE LC)?
Now referring to the attached diagram that i've sketched out, there are 2 possible scenarios for link redundancy at a local access site.
The 1st scenario deals with a ptp circuit for a customer btw Site#1 and Site#3 across the MPLS. Since with 7600 we could just use int vlan as a conduit to link both physical interface before tunneling across the l2vpn circuit. So in the event of the active link fails (top UPE), the backup link (bottom UPE) takes over (Spanning-tree will take care of that). When we swap with the ASR9K, there is no notion of SVI and it uses sub-if with encapsulation dot1q. So here's what I came up with for the ASR9K (pls refer to the attached configlet). Would this be a good approach? Can this work?
The 2nd scenario is a bit tricky, as with 7600, the SVI is sort of disassociated from the physical interfaces (dot1Q trunks) that connect to the UPE. So in the event of active link failure (top UPE), the backup link (bottom UPE) takes over (again STP does the work!) - SVI remains up, IP address (gateway for CE1) is still reachable. Now with ASR9K, since the sub-if is tied with Physical interface how would I be able to approach this? I don't think its even possible to configure same IP address on two different sub-ifs (IP address is global IP, no VRFs is used), let alone trying to find if there's an equivalent to IOS interface "backup" cmd.
Thanks and very much appreciated.