Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements
You may experience some slow load times, errors, and slight inconsistencies. We ask for your patience as we finalize the launch. Thank you.

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

New Member

BGP / OSPF - multihomed to 2 ISPs via multiple local routers

I was wondering if anyone could point me into the right direction in setting up a multihomed environment to 2 ISPs via multiple local routers using OSPF / BGP ???

Any config examples would be much appreciated.

This is the scnario:

ISP A ISP B

^ ^

^ ^

Router1 ---- Router2

| \ / |

| \ / |

| / \ |

| / \ |

Router3 --- Router4

Router1 eBGP with provider A

Router1 iBGP with Router2

*also runs OSPF

Router2 eBGP with provider B

Router2 iBGP with Router1

*also runs OSPF

Routers 3 & 4 run OSPF

  • Other Network Infrastructure Subjects
7 REPLIES
New Member

Re: BGP / OSPF - multihomed to 2 ISPs via multiple local routers

http://www.cisco.com/warp/customer/459/40.html#4

Should help you out there.

Jeff

New Member

Re: BGP / OSPF - multihomed to 2 ISPs via multiple local routers

I am unable to open the site.It is asking for a CCO login.

Gold

Re: BGP / OSPF - multihomed to 2 ISPs via multiple local routers

New Member

Re: BGP / OSPF - multihomed to 2 ISPs via multiple local routers

Thanks for you reply Jeff, ... I have seen this doco, I have the BGP setup pretty much under my belt my the OSPF routing is what I am the most interested at this moment, in particular to do with edge routing, boarder routing.

Cheers,

Gold

Re: BGP / OSPF - multihomed to 2 ISPs via multiple local routers

What part of the ospf configuration are you interested in? It should just be straight making certain both routers are running ospf, and they can see the next hops that BGP needs correctly.

Unless you're thinking about the synchronization stuff (which has been marked as historical by the IETF, and the defaults should flip on Cisco at some point, I would think, to no sync) (?).

:-)

Russ.W

New Member

Re: BGP / OSPF - multihomed to 2 ISPs via multiple local routers

Well, I am new to OSPF ... so any cofig examples that fall within my requirements will help.

The diagram that I published before didn't come up the way I want it, ...so here it comes the 'written' vesion:

The 4 routers live in a fully meshed environment

Router 1 has 3 int, 1 to ISPA, 1 on network 1.1.1.0, the other on network 1.1.2.0

Router 2 has 3 int, 1 to ISPB, 1 on network 1.1.1.0, the other on network 1.1.2.0

Router 3 has 3 int, 1 on network 2.2.1.0(internal nw), 1 on network 1.1.1.0, the otehr on network 1.1.2.0

Router 4 has 3 int, 1 on network 2.2.2.0(internal nw), 1 on network 1.1.1.0, the otehr on network 1.1.2.0

Any help would be much appreciated.

New Member

Re: BGP / OSPF - multihomed to 2 ISPs via multiple local routers

Hi-

You may have seen this link already but it will tell you how to best solve your OSPF config/design with what you want to do. If your new to OSPF this would be a good place to start.

http://www.cisco.com/en/US/tech/tk365/tk480/technologies_design_guide09186a0080094e9e.shtml

or

http://www.cisco.com/en/US/tech/tk365/tk480/technologies_q_and_a_item09186a0080094704.shtml

191
Views
0
Helpful
7
Replies