PBR multi-interface question

[blawrimore1]

Ive got a situation where i have three possible physical point to point interfaces that i can use for traffic.  one interface will be for normal LAN traffic and the other two will be reserved for FCIP traffic which is distinguishable by its port number, 5223 i believe.  for other reasons in my routing table, i'd rather not mark my lan traffic as this will be bi-directional and could end up anywhere.  the FCIP traffic will have definate source and destination addresses, along with the port number.

my question is, how do i get the FCIP to use BOTH interfaces at the same time.  I dont think that EtherChannel is a possibility here as the link is via an ISP.

thanks

[Laurent Aubert]

Hi,

Are you receiving FCIP destination subnets from all the 3x links ? if yes via which protocol ? The idea would be to play with the routing protocols if possible so those subnets are received equally via 2x links and with less interesting metrics from the 3rd link.

Thanks,

Laurent.

[blawrimore1]

we have eigrp running on all three links.  we havent played with the metrics on the links themselves yet, but further away from the links, at the core, we specify that certain traffic should be routed to the switch that terminates the three links.  in the future, we want all traffic to prefer that switch, but dedicate 2 links to fcip and one link to all other traffic.

i definately want to play with the metrics, but each time i sit down to look at the algorithm, i come up with something that will break.  if i touch the non-fcip traffic, we may get a routing loop if its destined for the internet because of wccp and bgp.  if i touch the fcip traffic, then it will only use one link instead of two, or the two links will not be utilized most efficiciently.  i know i may be missing something when it comes to the protocol and/or pbr, but i havent put it together yet; i havent had the epiphany.

thanks

[Laurent Aubert]

Hi,

PBR can be the solution but you will not achieve load-balancing. It will be more nominal/backup scheme.

Assuming you don't want FCIP traffic to use the third link even if the other two are down, you could just apply a distribute-list in inbound filtering FCIP subnets from the interface you don't want this traffic to use:

http://www.cisco.com/en/US/docs/ios/iproute_pi/command/reference/iri_pi1.html#wp1018093

HTH

Laurent.