[GRLUG] Rookie Network Question

[L. V. Lammert]

At 05:22 PM 1/24/2013, Benjamin Flanders wrote:
>Not looking to take up too much of anyone's time, but is it possible 
>to have two internet connections combined?  I'm looking at upgrading 
>our companies internet.  Currently we have a single T1 line.  Quite 
>slow and expensive.   I'd like to look at some of the cheaper 
>options, like a Comcast Business Line.  The issue with that is that 
>it doesn't have an SLA.  It would be awesome to be able to have the 
>cheap fast line with the T1 as a backup.  That way we can 
>dramatically increase the speed but still have the solid line with 
>the SLA as a backup.
>
>I have googled and found out about dual wan routers, this would work 
>for stuff originating in house but not stuff originating 
>outside.  Is it possible to combine two disparate lines so that even 
>requests coming in will failover to the backup if the main line is down?

The simple answer is no, .. except in the case of outbound access 
only. In that case, you can switch from one to the other, or setup a 
router with both connections and setup some firewall rules to decide 
which connection to use by IP.

For *incoming* connections (i.e. to a public server), you would have 
to advertise your own BGP, which is both expensive and complex.

If you have a T1 now, the better solution would be to get a quote on 
bonded T1s (two, or even three) from your provider. You would have an 
SLA, and most enterprise routers will support bonded T1s (even the 
lowly Cisco 1725, which we have).

         Lee