I was asked to look into multi-honing. Does anyone know what it is and how I can do it (where to go next?)?

I think multi-honing is when you sharpen two knives at once :).

This reminds me of the Dilbert cartoon where his boss comes over and tells Dilbert they need more Eunuch programmers :D.

Anyway...what you probably want is multi-homing. A multi-homed site is a site that connects to two, or more, diverse backbones (ie Qwest and Sprint). Ideally these connections should be to two different Central Offices so if one blows up, the second connection is completely unaffected.

This is the TG* version of how to do this:

First, get yourself an ASN from ARIN (last check $500 a year): http://www.arin.net/regserv/asnguide.htm

Then get yourself two Internet connections, preferably both faster than a T1 (you'll see why soon :)). You may have to be in the ordering process in order to get your ASN, so these steps kind of overlap. You must tell your ISP you intend to be multi-homed with your own ASN. Because they will want to hand-off to that ASN.

Before your connection is live purchase two routers (you can run both connections into one router, but that kind of defeats the purpose). I prefer Cisco 3600s, but Foundry, Imagestream and others. Make sure it has at least 64 megs of RAM and supports multi-homing protocols.

Now, decide if you are going to use BGP or OSPF. One or both of your ISPs will probably force you to use BGP, but OSPF is better. Either way the amount of routes that your routers will collect can flood a T1, so if you are multihoming T1s, you may want to rethink your strategy.

When the connections are delivered configure your routers with BGP/OSPF enabled and set static routes pointing to your upstream provider's ASN.

Tada...you are now multi-homed.

*TG=Tim Greer :D

Deaner listen to what uallan says b/c he's root ;p

What are the advantages of BGP over OSPF ? or vice versa.

thanks

The reason, in this case, you want to use OSPF over BGP is this:

OSPF (Open Shortest Path First) was designed from the start to be low overhead, and work in conjunction with static routes. In this situation you basically need two static routes on each router:



[Router 1]<--- Static Route 2 ---> [Router 2]
| |
| |
Static Route 1 Static Route 1
| |
| |
[Upstream ISP] [Upstream ISP]


You obviously want to rely on the ISP's routers to do the majority of the work. OSPF does a better job of breaking the Internet into larger chunks, so there is not as much overhead for the router.

BGP (Border Gateway Protocol), on the other hand mires itself in the minutiae of the Internet. So, while OSPF is only going to keep routes for /20s or higher, and trust the upstream router to take over from there, BGP is going to try to map every class C it can rather than letting the upream routers handle it. So, if you have 64 megs of RAM you may wind up with 45 or 50 megs worth of routing tables with BGP, as opposed to 20-25 with OSPF.

Uallan, as usual you provide us with a wealth of info :)
i might ask for some more info on some issues regarding OSPF sometime...

thanks again.

Thanks a ton for your help, keep it coming if you have more to add but this is a great map for me to start on. Thanks again.