[isp-bgp] Re: Sample BGP Config

[Brandon Peskin <bpeskin@...]

On Tuesday, July 15, 2003, at 02:47  PM, Christopher J. Wolff wrote:

> Hello,
>
> I'm looking for a couple of sample cisco configs that illustrate two
> multihomed routers connected by an IGP session.  For example;
>
> Router 1----------Isp 1
> |
> |
> IGP
> |
> |
> Router 2----------Isp 2
In the first example you can run iBGP between your routers, without 
problems. In example two, you can use OSPF as your IGP.

Keep in mind these are very basic. You'll want to make yourself 
familiar with route-maps to ensure you aren't back washing routes 
between your providers into one another.


Sample:

router bgp 1234
! set up globals to your BGP configuration
bgp log-neighbor-changes
network 192.168.0.0 mask 255.255.0.0
network 10.0.0.0 mask 255.0.0.0
! now define the configuration for our other peers on our network
neighbor iBGP-Peers peer-group
neighbor iBGP-Peers remote-as 1234
neighbor iBGP-Peers update-source Loopback0
neighbor 192.168.0.2 peer-group iBGP-Peers

! Now let's do BGP with our directly connected ISP
neighbor 1.2.3.4 description ISP 1
neighbor 1.2.3.4 remote-as 4567


Using OSPF:

Router 1:

router ospf 1
redistribute connected subnets
! if you have static routes, also include this one
redistribute static subnets
network 192.168.0.1 0.0.0.0 area 0
default-information originate metric 100

Router 2:
router ospf 1
redistribute connected subnets
! if you have static routes, also include this one
redistribute static subnets
network 192.168.0.2 0.0.0.0 area 0
default-information originate metric 200

then use the BGP configuration above without the iBGP-Peers

This is only off the top of my head. I hope this helps.
--
Brandon Peskin
Lead Network Engineer
A-Link Network Services
bpeskin@.../408-720-6162