07-30-2012 05:13 AM - edited 03-01-2019 02:36 PM
Good day.
I have a following situation:
- Cisco 7600/RSP720-3CXL(12.2(33)SRD4 software) as a border with 2 fullview uplinks and a bunch of peerings
- a customer, who generates large amount of egress traffic(~8Gb/s), half of which goes to uplink2, and half distributed among the peerings
Issue is, that uplink2 is a pricy one. Management wants that this customers' traffic was forwarded through the uplink1, rather that uplink2
And here's where fun begins. Policy routing is performed before the normal routing, and I only can specify "next-hop something" there(so we can make "from A to uplink1" config, but not "from A to ANY AND NOT uplink2" config). So if I use this - all customers' traffic flows through uplink1, and nothing goes to the peerings. Such situation is unacceptable.
I thought about the technique I use on Juniper routers - rib-groups.
I want to create a VRF, in which I'll copy all the routes from global RT except the uplink2. Then in the policy routing I can specify VRF for this cutomers traffic, where it'll be forwarded in "from A to ANY AND NOT uplink2" fashion.
Problem is I have no experience working with VRF on Cisco, and examples I find are only for from-VRF-to-VRF route import - I can't find how to do a from-global-to-VRF route import.
Questions are:
- am I not overthinking this? Maybe there's an easier solution to this issue?
- can someone provide me an example of how to perform this global-to-VRF route import?
08-22-2012 06:00 AM
This may be of help to someone later. I found this link http://chetanress.blogspot.com/2010/08/importing-routes-from-global-table-into.html with instructions on global-to-VRF route export.
Example of config:
ip prefix-list chetan seq 10 permit x.x.x.x/x
ip prefix-list chetan seq 20 permit x.x.x.x/x
ip prefix-list chetane seq 30 permit x.x.x.x/x
!
ip vrf ckumar
rd 50:1
import ipv4 unicast map CHETAN_IMPORT
route-target export 50:1
route-target import 50:1
!
exit
!
route-map CHETAN_IMPORT permit 10
match ip address prefix-list chetan
I did not test it(used Juniper box for this task), but it seems to be the right solution.
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