BGP and ASN assignments

[TheZman78]

I am currently working on a project that involves multihoming a 10Mbps Metro-E /24 with a 100Mbps Metro-E /27 from two different ISPs. I need to get BGP info from the ISP own the /27 however, they tell me that ARIN requires a /24 in order to assign an ASN to block.

Do I really need a /24 to get an ASN for BGP? Can someone point me in the right direction as to what is involved in a project such as mine? Thanks!

[Richard Burts · Accepted solution]

Andrew

I believe that they are probably correct about the requirement for a /24. And I know that many Services Providers will not accept advertisement of a /27 over the Internet.

I would suggest that you think in a different direction. A /27 is a fairly small block so it is likely that you would need to translate addresses of the hosts inside your network as they go out to the Internet (at least through this provider). In which case you can just translate your inside addresses into this /27 block as they go to the Internet. And that means that you do not need to run BGP with that provider. You will have routes that point to them as one path to the Internet and they will have routes to their block of addresses associated with your network.

HTH

Rick

[TheZman78]

Thank you Rick for getting back so quickly!

So, does that mean I will not be able to load balance and multihome the circuits?

What I am trying to accomplish is that I want all VoIP calls to use the 10Mbps circuit, and all data (web browsing, file transfers and downloads, ftp, etc) to use the 100Mbps circuit.. in the event the 10Mbps gets saturated, I want the router to load balance and QoS the traffic onto the 100Mbps circuit until the traffic for VoIP (in this case SIP) slows down below a threshold, then once it's got below the acceptable threshold, I want the router to reroute the VoIP traffic back to the 10Mbps circuit.

Would it even be possible to do this w/o using BGP? If so, can you point me in the direction of some technical docs that could help? Again, I appreciate all your help!

[Richard Burts · Accepted solution]

Andrew

I believe that it should be possible to load share over the links but not using BGP to accomplish that. I believe that you could set up the routing so that normal traffic went over the bigger link and you could configure Policy Based Routing so that the VOIP to use the smaller circuit. Those parts should certainly be feasible. I configured something pretty similar for a customer and it did work pretty well. Getting QOS to monitor and move traffic between links would be challenging at best. I have not done anything quite like that and believe it would be difficult. I am not ready to say that it would not be possible, but someone other than me would have to offer an opinion on that aspect.

HTH

Rick