BGP vs OSPF

balajee · ‎06-16-2007

Hi,

I am new to BGP. Why shouldnt we use OSPF instead of BGP? What are the advantages it has over OSPF? Welcome if any links or provided. Thanks in advance.

Thanks,

Balajee

s.arunkumar · ‎06-16-2007

The first reason is that BGP is more scalable than OSPF.

ie,The ISP level of routing do had large number of routes,

which igp routing protocols like ospf cannot handle.BGP

handle such large routes between AS.

second reason,bgp allows more options for routing manipulations and

optimization by using routing policies (by manipulating

attributes)which is required when routing between AS

, and this, normal igp like ospf cannot perform.

lets here more from the experts too........ :)

...arun :)

Jon Marshall · ‎06-16-2007

Hi Balajee

Generally speaking OSPF and BGP are routing protocols for two different things.

OSPF is an IGP (Interior Gateway Protocol) and is used internally within a companies network to provide routing. Company here could small/medium/large business/service provider etc. In technical terms OSPF is used within an autonomous system, an autonomous system being a network under the administrative control of one organisation.

BGP is an EGP (Exterior Gateway Protocol) whose primary use is to exchange routing information between autonmous systems and not for routing within an autonomous system, although the waters get a muddy here as you use IBGP to route within your autonomous systems. BGP is the routing protocol that makes the Internet work.

HTH

Jon

mohammedmahmoud · ‎06-16-2007

Hi,

To add a small info to Jon's and Arun's wonderful info, BGP is the best solution for multihomed networks (when a network is taking a service from 2 service providers) due to its powerful routing policy tools.

HTH,

Mohammed Mahmoud.