In article , wrote: :Can you load balance 2 T1's on a 2600 or 3600 series if they are from :separate carriers?
Yes.
:All the diagrams I see show load balancing only :when the circuits are between 2 routers.(1 carrier)
Not surprising.
:Will round robin dns work on the ISP side (if they'll do it) with two :totally separate external IP's?
Round Robin DNS is not very much "load balancing" -- and it doesn't require any co-operation from any ISP, just some configuration in the DNS tables.
*Incoming* load balancing in public IP space requires the use of a protocol such as BGP -- and not many carriers are willing to be BGP peered with a different carrier [though you can always through money at the situation.]
Outgoing load balancing is something you can do on your own... as long as you keep in mind that the return packets are not necessarily going to come back through the same interface you sent the packet out, and incoming packets won't be round-robin'd through the links... oh, and keep in mind that some ISPs block outgoing packets from IP spaces they don't know about.