WAN Link Aggregation

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devin_m

Limp Gawd
Joined
Jun 8, 2011
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I'm in the early planning stages of starting a colo business and I'm looking into redundant WAN links, I'm looking at getting fiber from two companies aggregating them with automatic fallover. Is link aggregation the best option? Am I even looking at the right solution for want I want? The issue I can see is each server we are hosting will need it's own public IP which I don't think is able to be done with aggregation from different ISPs. I'm looking to do this right (no trying to run consumer or whitebox hardware in a business environment), any help or advice would be greatly appreciated.
 
You don't need to have two different ISPs necessarily for WAN redundancy. Something like AT&T's MARO solution can achieve the same result. Two CPE routers each with their own leased line that use BGP for path redundancy to your assigned IP block works very well without having to engineer a solution yourself. You can take the IP block of whatever size you want to pay for and then NAT or whatever you want with it.
 
I'm looking at a Cisco solution as that is what I am most familiar with what would you go with as the edge routers? I'm looking at about 200mbps WAN links, something like a 3945 ISR? or a ASR 1002? Or do I need to even be looking that high?
 
mattjw916 said:
You don't need to have two different ISPs necessarily for WAN redundancy. Something like AT&T's MARO solution can achieve the same result. Two CPE routers each with their own leased line that use BGP for path redundancy to your assigned IP block works very well without having to engineer a solution yourself. You can take the IP block of whatever size you want to pay for and then NAT or whatever you want with it.
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The issue with using one company might be that if it is a lateral off of the ring and if the lateral is cut then both links will go down providing no redundancy. After working in a NOC for a fiber company, I would suggest using 2 different companys if possible.
 
etothe3ric said:
The issue with using one company might be that if it is a lateral off of the ring and if the lateral is cut then both links will go down providing no redundancy. After working in a NOC for a fiber company, I would suggest using 2 different companys if possible.
Click to expand...

I was thinking the same thing, the only issue I see with that is the IP issue mentioned above.
 
mattjw916 said:
You don't need to have two different ISPs necessarily for WAN redundancy. Something like AT&T's MARO solution can achieve the same result. Two CPE routers each with their own leased line that use BGP for path redundancy to your assigned IP block works very well without having to engineer a solution yourself. You can take the IP block of whatever size you want to pay for and then NAT or whatever you want with it.
Click to expand...

+1. I work for Comcast as a MetroE Engineer and many of our customers go this route. All you need is 2 edge routers, and use BGP to dual home. You can also purchase static IP blocks based on your needs. Having said that in order to use BGP you will need your own AS number so you can advertise routes. Keep that in mind.
 
devin_m said:
I was thinking the same thing, the only issue I see with that is the IP issue mentioned above.
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It all depends on how much money you want to spend really. Sure you could buy your own block of IPs (lots of paperwork and money) and then set up BGP peerings to two different ISPs (lots of work) using two different routers and advertise your network that way.

A managed solution will have a faster turn up time, lower cost, less management overhead and with circuits coming in from geographically diverse places the odds of an outage impact both lines is extremely small.

There is still always a chance of losing both links even with two different ISPs for any number of reasons. Just because a different name is on the bill that doesn't really ensure any kind of diversity. Everything regardless of the carrier eventually runs over Qwest's lines to a DWDM ring managed by another provider at my datacenter. If a truck crashes into one of the COs, it's lights out unless you had CO diversity as well for where you are cross-connected into the ring.

Anyway, just something to think about. Buy as much redundancy as you can afford (or need).
 
BGP is your friend.

Are you building from the ground up or buying space in an existing colocation provider?
From a customer point of view, I would expect diverse carriers at a minimum. Unless your going the super cheap hosting with 1gig cogent connection.

Also, getting started, I would head over to webhostingtalk.com. Lots of very experienced folks there and they can answer many of your questions.
 
Thanks for all the help everyone this is why I love this forum so many people know so much. We have a few bulk data carriers up here in Alberta so I'm going to set up conversations with each and one of the main things I'm going to check out is who owns their pipes, one of the only ones I know that owns their own fiber is Telus but I've been looking at Allstream as well. I'm looking to do this from the ground up, renting premises, getting power, back up generators and the such. I'm going to do a lot of reading on BGP and exploring getting our own /24.
 
While you are at it, read up on IPv6... IPv4 is nearly out of space, and soon everything will be going IPv6 (like it or not).
 
Yeah I was going to look into offering both an IPv4 and an IPv6 address to clients when they use us.
 
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