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BGP Question

Hi!

Any assistance will be greatly appreciated!  This is the scenario...

We have two 7200s, I will call them R1 and R2.  R1 connects to ISP1 and R2 connects to ISP2.  R1 and R2 runs HSRP and our FWSM points to the HSRP as the gateway out to internet.

R1 has two interfaces, FE0 and FE1.  FE1 connects to our 6509 where the FWSM resides on a switchport.  FE1 connects to the metro.

R2 has two interfaces, FE0 and S1/0.  FE0 connects to our 6509 where the FWSM resides on a switchport.  S1/0 connects to T3.

R1 and R2 both receives full BGP routes.  R1 and R2 in the same AS running iBGP.  Local preference are the same for both.

We ran into couple of issues trying to use both ISPs, hoping load sharing our internet bandwidth for outbound..

HSRP primary goes to R1, so all internet out traffic goes there first through FE0 on R1.  When the traffic needed to be routed through ISP2, R1 sends the those traffic back through the same interface FE0 on R1.  Unfortunately, almost 70% of the outbound traffic gets routed through ISP2.  It's only a 100mb link, so that link is constantly saturated because of it.  Should we either upgrade the fastethernet to a gig or add a separate link between the two 7200s?  What's the common practice with what everyone is doing?

Second problem is since 70% of the outbound traffic goes through ISP2, the T3 is peaked..  is there any way we can force certain outbound traffic through the ISP we choose?

Thanks for your help in advance!!  I'm still noob in BGP, please let me know if I missed any info needed to provide.

C

1 REPLY
Hall of Fame Super Silver

Re: BGP Question

Hello Chinglee,

>> Second problem is since 70% of the outbound traffic goes through ISP2, the T3 is peaked..  is there any way we can force certain outbound traffic through the ISP we choose?

you can set an higher local preference for selected routes learned by ISP1 in order to get a more fair load sharing in outbound direction

something like

on R1

route-map setpref permit 10

match as-path 11

set local-preference 150

router bgp yourASN

neigh ISP1 route-map setpref in

Hope to help

Giuseppe

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