>Hey all,
>
> My company has been annoyed by recent provider outages and wants to
>start to use dual internet routes through the same ISP BUT different pops.
>We are currently getting 2 Cisco 3640 routers with 128 of ram in each for
>possible future FULL BGP routes, although currently we would only be getting
>partial. My question is, does anyone have any advice or caveats about this
>type of configuration (from the router side and the ISP side). Any help
>would be much appreciated. Thanks.
>
This will depend, in part, whether your address space is
provider-independent or is part of your provider's allocation. See
RFCs 1998 and 2270.
In either case, the key is that you want to advertise your routes to
the provider at both POPs, in a manner that lets the ISP know that
all of your routes are reachable at both points, and, if possible,
are to some extent load balanced.
Assume that your allocation is 192.0.2.0/23, and you can split your
addresses so that the western part of your network has addresses in
192.0.2.0/24 and the eastern part is in 192.0.3.0/24.
A simple technique is to advertise
West Border East Border
192.0.2.0/23 192.0.2.0/23
192.0.2.0/24 192.0.3.0/24
An alternative would be
West Border East Border
192.0.2.0/24,MED=100 192.0.2.0/24, MED=200
192.0.3.0/24,MED=200 192.0.3.0/24, MED=100
Whatever method you use, it MUST be coordinated with your provider.
As specified in RFC 1998, if you are multihomed to a single provider,
and your address space is a subset of their allocation, mark your
routes with the NO-EXPORT well-known community.
Message Posted at:
http://www.groupstudy.com/form/read.php?f=7&i=5054&t=5028
--------------------------------------------------
FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
