[nsp] Load Balancing with BGP over unequal-cost circuits

[Tay Chee Yong]

Hi Brian,

Yes. It only indicate a single bgp neighbor, as the bgp peering is between the 2
loopback interfaces, that is "binding" the 2 interfaces together with the static
route.

Sorry, but what is IIRC?

Regards,
Cheeyong

On Wed, 2 Oct 2002, Brian Wallingford wrote:

> The config you've forwarded indicates only a single bgp neighbor.
>
> BGP will, by default, load balance if all available paths are equal, and
> you've specified max-paths.  BGP to multiple upstreams will not
> load-balance due to its nature, but to a single AS, it can be very
> effective.  IIRC, there is a very intuitive case study on CCO which covers
> this nicely.
>
> hth,
> brian
>
>
> On Wed, 2 Oct 2002, Tay Chee Yong wrote:
>
> :Hi all,
> :
> :My understanding is that BGP doesn't do load balancing because of its nature of
> :selection of best path, however load sharing can be achieved.
> :
> :I have a customer who is doing load balancing over an E1 (2Mbps) and a 1Mbps
> :circuit (unequal bandwidth) using BGP, and it seems to work.
> :
> :Could someone advise how was the load-balancing achieved?
> :
> :Following is the config :
> :
> :* Note : Both circuits are terminated to the same router on both ends. *
> :
> :interface Serial0/1
> : description ==> Link 1Mbps
> : bandwidth 1024
> : ip address 192.168.252.206 255.255.255.252
> : no ip redirects
> : no ip proxy-arp
> : ip load-sharing per-packet
> : no fair-queue
> : hold-queue 4096 out
> :!
> :interface Serial0/2
> : description ==> Link 2Mbps
> : bandwidth 2048
> : ip address 192.168.252.202 255.255.255.252
> : no ip redirects
> : no ip proxy-arp
> : ip load-sharing per-packet
> : no fair-queue
> : hold-queue 1024 out
> :!
> :
> : network 172.16.0.0 mask 255.255.192.0
> : network 172.16.64.0 mask 255.255.192.0
> : network 172.16.128.0 mask 255.255.192.0
> : network 172.16.192.0 mask 255.255.192.0
> : neighbor 192.168.255.202 remote-as 65500
> : neighbor 192.168.255.202 ebgp-multihop 3
> : neighbor 192.168.255.202 update-source Loopback0
> : neighbor 192.168.255.202 version 4
> : neighbor 192.168.255.202 soft-reconfiguration inbound
> : neighbor 192.168.255.202 route-map ksc-in in
> : neighbor 192.168.255.202 route-map ksc-out out
> :
> :ip route 172.16.0.0 255.255.192.0 Null0
> :ip route 172.16.64.0 255.255.192.0 Null0
> :ip route 172.16.128.0 255.255.192.0 Null0
> :ip route 172.16.192.0 255.255.192.0 Null0
> :ip route 192.168.255.202 255.255.255.255 Serial0/1
> :ip route 192.168.255.202 255.255.255.255 Serial0/2
> :
> :
> :access-list 21 permit any
> :access-list 22 permit 172.16.0.0 0.0.255.255
> :
> :route-map ksc-out permit 10
> : match ip address 22
> :!
> :
> :route-map ksc-in permit 10
> : match ip address 21
> : set local-preference 500
>
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