The term "multi-homed" is used commonly by bandwidth providers as a sales pitch to attract your business. Do you know what this means? If a provider claims to be multi-homed, are they truly multi-homed?

Multi-homed is used to refer to the practice of hooking one network to the Internet at more than two places, giving the network multiple paths to the Internet and providing speedier connections around the world as well as giving their network a better level of redundancy in case of network issues or fiber cuts.

Note: A network with two connections should be referred to as dual-homed, but that term has not been used since the beginning days of the Internet and most providers will still call their networks multi-homed even if it is dual-homed.

A multi-homed provider is far superior, and usually pricier, than a provider that has just one or two connections. However, a provider may not actually be multi-homed; it may just be very close to a network that is multi-homed. This fact is often not well explained on the provider's website.

Many providers will locate their equipment in a data center and then connect it to a larger carrier, such as Level 3, Broadwing, or MFN. These carriers are very well connected and without a doubt deserve the title multi-homed. But does being connected to one of these carriers give you the right to call yourself multi-homed? I don't think so. When a provider is connected to one of these guys, they have only one connection, even though one hop away there are several connections. The provider still has one single point of failure that can cause a network to go down.

So, how do you tell if a provider is truly multi-homed or just pretending to be multi-homed? The easiest way is by looking at their bandwidth page to see if they say they are linked up to several places with huge connections. Very rarely does a hosting provider have so many connections. If a provider says they have an OC-12 to AOL, an OC-12 to MAE-WEST, an OC-12 to MAE-EAST, and blah blah blah, more than likely they are listing the connections that their upstream carrier has and not the connections that they, themselves, have.

Does this matter? Well, providers normally locate their equipment within the same building as the large multi-homed carrier and therefore simply run an Ethernet to them. In this case, there isn't a whole lot of difference. Although there may be a problem with that Ethernet, it is rare and easily fixed. It is also important to note that 95% of the hosting providers are setup this way so if one says they are multi-homed, it doesn't mean squat when comparing it to one that doesn't say it.

How can you tell if a provider that is truly multi-homed? Usually, this will be a major marketing point in their website but it will not seem overstated as I mentioned above. The best way to find out is to call them up and ask them a few questions:

"Who is your upstream provider?" A true multi-homed company will say they don't have an upstream provider, but they have connections to a few carriers.

"What kind of router do you use?" A true multi-homed company that uses fiber (OC-X) will need a pretty tough router to handle the multiple paths such as a Cisco 7000, 10000, 12000 or a Juniper M20, M40.

Keep in mind that a true multi-homed provider will be more expensive but far superior for mission critical websites.