Dual Homed Setup

[Anonymous]

Hello,

We have two ISP's that we Peer with. Currently we have one 3140 with both ISP's feeding into the router but obviously this creates a single point of failure. Is there any documentation on setting up a 3140 per each carrier that we have for BGP Peering?

Thanks!

[jayh]

The 3140 isn't going to hold a full table, let alone two. If you're doing an active/failover scenario you could take a default from each ISP to a 3140 and use VRRP on the LAN side of the two 3140s or come up with a simpler load-balancing scenario.

Are you presently multihomed grom a BGP standpoint? As in, does your organization have an ASN and its own public IP space? If you're going to be playing in the BGP default-free sandbox, you're going to need that as well as more robust hardware than the 3140.

[Anonymous]

Hello,

Well actually we use one 3140 with Full Routes from one carrier and partial from another and it works fine. We are using a failover scenario so if one ISP goes out, it fails everything over which works fine as well. We are at about 60% on CPU Load.

Yes we have our own ASN and our own IP Space.

Travis Poole | President

O: 919-897-2081 | TF: 855-749-1737 | TravelingMailbox.com

[jayh]

Well, if it's working for you, then just get a second one and run iBGP between them, use VRRP on the LAN side. If you have other internal routers go with an IGP such as OSPF.

Of course, eliminating single points of failure can be an ongoing challenge and eventually comes down to a risk/reward decision. The LAN side switch tying them together will be a single point of failure so a switch stack is in order. You'll want two UPSes, (the 3140 doesn't have dual power supplies, so make sure they're on different ones) at least one generator with ATS, verify that your two feeds coming in different conduits in different trenches, and the list goes on.

[Anonymous]

Yes I understand. We have two different fiber connections (two different carriers and two different physical lines). We have entire rack of servers with equipment all on UPS’s and a Standby 22kw Generac Generator.

Travis Poole | President

O: 919-897-2081 | TF: 855-749-1737 | TravelingMailbox.com

[Anonymous]

Do you by any chance have a link to any documentation on this?

Thanks!

Travis Poole | President

O: 919-897-2081 | TF: 855-749-1737 | TravelingMailbox.com

[jayh]

I don't see anything in the datasheet or on the Adtran site showing memory or number of BGP routes. The 3140 is listed as an access router in the literature which to me implies a customer edge device. It wouldn't be my choice for an eBGP border router taking multiple full tables. Depending on the architecture, for example if it's a fixed TCAM space, when the global table exceeds its capacity the failure mode can be rather quick and unpleasant.

With your present setup if one ISP bounces, how long does it take the single 3140 to reconverge? It might be a sleeping giant that's up to the task, but I think a call to Adtran support might be in order. I'd ask for pre-sales so you don't get bogged in the regular support queue. Are you dual-stack v4/v6 and if not is that in the works?

[Anonymous]

Hello,

Well its only happened once but it fails over pretty quickly from what I have seen. Within 5 minutes for sure. We are doing some reading on ibgp and I will probably get presales a call to see what we can come up with.

Travis Poole | President

O: 919-897-2081 | TF: 855-749-1737 | TravelingMailbox.com