nd_tech
join:2003-04-10
Troy, MI
| BGP baby
ok, so my boss okayed the new T from a different ISP. So I'll be load-balancing between 2 different ISP's for fail-over. I was just curious if there was any good documentation for doing this. I searched Cisco's website, but we all know how their search feature works. Any input would be greatly appreciated.
Thanks |
|
dpocoroba
Premium
join:2000-11-14
224.0.0.5
| Search for "Multihoming" here are a few quick links that will get you started. As a FYI i'm sure you know BGP is not something you can just "put together" and requires a decent understanding of the protocol. Just remember to be careful when playing around with BGP routes  HTH
»www.cisco.com/en/US/tech/tk365/t···6d.shtml
»cisco.com/en/US/tech/tk365/tk80/···.shtml#4
--
"Knowledge is contagious, infect" |
|
jdmatl
join:2000-04-27
Deerfield Beach, FL
| reply to nd_tech
Humm, Not BGP but CEF
Load Balancing with CEF
»www.cisco.com/en/US/products/hw/···eb7.html
Alternatives for High Bandwidth Connections Using Parallel T1/E1 Links
»www.cisco.com/en/US/products/hw/···4b.shtml
How to Use HSRP to Provide Redundancy in a Multihomed BGP Network
»www.cisco.com/en/US/tech/tk365/t···2c.shtml
GLBP - Gateway Load Balancing Protocol
»www.cisco.com/en/US/products/sw/···1c8.html
If course if you have another $20k, this would be the route
»www.fatpipeinc.com/
No bgp needed and you can add 2, 4, 6 T'1s and it will "add them up" to give you 2megs 4meg 6megs of thruput. |
|
GeoffBelknap
join:2004-01-29
Albany, NY
| reply to nd_tech
Running Multi-homed BGP is a great way to gain some BGP experience.
Since you're going to use BGP, a great place to start researching configurations is Avi Freedmans webpage »avi.freedman.net/
He's written several articles and FAQs on Multi-homing.
Along the way you'll want to register for an ASN (Autonomous System Number). This will uniquely identify your AS and the routes you originate.
»www.arin.net/library/training/as···dex.html
If you find yourself wanting to learn the nitty gritty details pick up Sam Halabi's "Internet Routing Architectures" »www.amazon.com/exec/obidos/tg/de···&s=books
This book has way more information than you need for now, but a great book nonetheless.
Hope this helps.
Geoff |
|
jdmatl
join:2000-04-27
Deerfield Beach, FL
| reply to nd_tech
RE: ASN number
Better break out the credit card. I think ASN's are around $1,500. Also, hope both ISP's gave him an entire Class "C" or he won't be able to do squat.
Min. is a class C to use BGP and inject routes to your upstream provider and a ASN. Some ISP's will lend you an ASN from what I have heard.
always something...  |
|
boethius
Boo-Yah
Premium
join:2002-01-28
Winters, CA
clubs:
| reply to nd_tech
ASNs are $500 to register then $100 annually.
Not so bad, especially if you can afford the bandwidth already.
Is a /24 a minimum technical requirement for eBGP multi-homing? It's not an ASN assignment policy, according to ARIN, and since BGP is a classless protocol I can't imagine it's a technical requirement.
Or is this simply a best practice not to advertise aggregated routes smaller than /24? |
|
GeoffBelknap
join:2004-01-29
Albany, NY
| BGP doesn't have a minimum route requirement. But, every ISP has a different rule of thumb as to how small or large of an announcement they will take from you and how they will aggregate it.
Chances are that if you are multi-homing, you already have at least a single /24 allocated to you from your ISP. In some cases if you decide to multi-home, but have a relatively small IP allotment, Say /24, /23 or /22, your other ISP may be able to make arrangements to announce your address space even if they were assigned by another ISP initially.
If you have a shorter assignment (like a /21), ARIN may agree to directly assign you a /20. This obviously depends on the growth needs you can document and agreeing to renumber. And, get ready to open your wallet to the tune of at least $2500/year. |
|
peaches28
join:2004-01-18
| From my experience no ISP in existance will take less than a /24 prefix when doing EBPG peering. Otherwise the Internet route table would have millions of prefixes, as it is the 100K+ prefixes is beginning to be a burden. It is going to take at least the /24, and the ASN number as said earlier.
Hope that you will never need more than a /20, you might want to get 2 before thinking about something as large as a class B, those things are 10K anually. As was said earlier, BGP multihoming is one of the more complex configurations out there. While it is straightforward, a thorough understanding of the protocol is ver helpful. Lastly search for BGP multi-homing on Cisco's site and you will get loads of docs on how to do it. My prefered way to do it is to use MED, not AS path pad prepend, but in any case you must work out the methods you are going to use with Both ISP's. |
|
nd_tech
join:2003-04-10
Troy, MI | Geez, BGP seems pretty hardcore. Sounds like fun! Thanks for the input guys. This should be more than enough to get me goin'. |
|
