adairw wrote:rebelwireless wrote:Adair, do you have any backup or alternate paths for uplink? For instance, I have my primary backhaul into a datacenter and then on a different path I have a DSL (resellable!) as a backup. I push default route via OSPF and have this DSL with a very high path cost and then it NAT's. Additionally, I've been pushing out a couple low priority things like windows updates that way w/ static routes based on their ASN's perfixes.
so, that's a long winded way of saying I have 2 different paths to the internet. If I were to do this VPLS bridging back to the core, based on your example above, I would not be able to route anywere along the path.
Do you, or anyone else have a solution to this limitation?
Can I assume these two connections are in different geographic locations?
The cool thing about our network is the tunnels follow you. So right now I have two upstreams in my data center. But no geo redundancy at this time. But if I did, I think (and I need to test this on the bench) as long as I have another router with an identical config somewhere else in the network advertise the same loopback address in to OSPF of other router the tunnels would establish a connection to that router and everything would keep on working.
It's really no different than normal routing. The tunnels just have to be terminated somewhere that has the IP space for them. It does mean that I pretty much have to have an exact copy of my hardware running elsewhere. MPLS router, edge/bgp, BMU, etc.
One thing I'm not sure about is how to control advertising the loopback address of the MPLS router. Sure if it's dead, it wont be there. but what if it's not and something upstream from it is? Details I'd like to test one of these days.
Since the building we are is basically a "carrier hotel" we have lots of options for upstream providers and unless the building blows up, geo redundancy isn't really a huge deal to me. If the network ever get's big enough to warrant that I think we'd just segment the network to a closer fiber pop and either backhaul it to the data center or just have that network stand alone.. dunno..
What I'm working on now is building out rings in the network so that if I lose any one piece of equipment I can still operate. I have 6 high capacity links that feed out from my data center and I should be able to build three distinct rings to return traffic to the data center. My goal is to have two wispswitches, two mpls routers, two edge routers, two bmu's etc. so that no matter what fails things will route around and keep on working. Again I'm about to start labing this to work out the kinks... I'm sure I've over looked something.
With geographic redundancy, you just run the VPLS circuits to your two data centers and put a router at the end of each connection. This essentially creates a local LAN with your customers and two routers on it. You then run something like HSRP on the routers. To make it really fun, you could run an HSRP group on the client facing interface(s) and a different HSRP group on the internet facing side with another VPLS circuit connecting the "internet side" of the routers.
