03-23-2012 06:14 AM - edited 03-04-2019 03:46 PM
Hi all
I see most people use IGP's when in a corporate company, however I have seen alot of people using BGP also in corporate environments, this is alongside another IGP such as eigrp or ospf.
Why would people use both BGP and and IGP together?
also if I used BGP on my WAN and OSPF in my core, do people normally redistribute the routes into each other?
and with BGP if I use no synchronization command, can BGP pass the routes over intermidiate hops that dont use BGP or will this not work?
cheers
03-23-2012 06:17 AM
One reason is being multihomed to the Internet.
Another is using MPLS.
The the details of configuration vary by the needs.
03-23-2012 06:59 AM
Hi
but would we only need BGP on the router connecting to the internet? would we then normally just redistribute this route into our OSPF domain from BGP, what do most people do ? use a static to the internet routers running BGP then redistribute the static into the OSPF ?
03-23-2012 08:29 AM
In addition to Paolos remarks, BGP gives you an new set of "knobs & switches " to manipulate the hows and whys of
route advertisements even within the enterprise.
There is a school of thought that suggests using the IGP to build the infrastructure, then use BGP for policy.
03-23-2012 08:44 AM
can you ellaborate on this a little ?
03-23-2012 08:51 AM
You see some of this in an Sp environment. apps and routes to apps are all advertised via bgp, the IGP just exists to tie the pieces together. In the enterpise world, (its been a couple of years) we would use local preferences for gaining access to enterprise services and internet access.
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