Utilizing ISR Router for Multiple ISP connections

[matt.kurtzhals]

Hello, Looking to support multiple ISP connections.  I would like to build some redundancy for our incoming connections, however, not sure we will be able to utilize BGP.  Is there any other options?  I am trying to figure out how all our incoming connections (mail, vpn, etc) would know that the one ISP would be down and could route to another? 

Thanks,

[Martin Hruby]

Hello Matt

It all depends on the relation between you and your service provider(s). Either you advertise your network prefixes to them through some sort of routing protocol (i.e. BGP) and you receive network prefixes from them to reach the WAN (i.e. default route), or they have a static route towards your network and they propagate it to the WAN for you and you have a static default route pointing to the ISP.

Can you let us know how the routing is currently setup?

In any way, setting up a BGP peering with your ISP(s) should not be a major issue and there are various redundancy/load-sharing scenarios you might consider. Please have a look here for more information: http://www.cisco.com/c/en/us/support/docs/ip/border-gateway-protocol-bgp/13762-40.html

Best regards,
Martin

[Richard Burts]

I would suggest that you might rethink what you are trying to achieve and to clarify what motivates the change. The simple answer is probably that you want to achieve redundancy.

So I would then suggest that you think about what redundancy will protect and what is the most common source of problems. In my experience the problems are most often failure of a router or failure of a circuit. How often are there really problems when your ISP is actually broken? Provisioning a second router or a second circuit to the same provider will protect you from the most common problems and will avoid the complexities of having two ISPs.

HTH

Rick

[matt.kurtzhals]

Thanks Richard, I have been tracking the outage time on our main ISP and it is very good.  I have been holding out on my CEO by telling him that it would be a waste of money, however, if the ISP would have a fiber cut or go down for a length of time we would lose customer satisfaction along with revenue. 

[Richard Burts]

Clearly if you have a single fiber and there is a fiber cut then you will lose revenue and customer satisfaction. So the solution is to have a second fiber. But what says that the second fiber has to go to a second ISP? What I was trying to explain was that if you have two fibers (and if they go to different POPs) then you are protected from an outage caused by interruption of a single fiber. Having that second fiber go to a second ISP adds a lot of complexity and I am not convinced that having the second fiber go to a separate ISP adds a lot of value.

HTH

Rick