How to implement dual WAN load balancing on a Cisco 1811/K9?

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Starriol

Limp Gawd
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Jan 3, 2006
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Hi guys, I need to set up load balancing for an implementation. We have 2 WAN links, one 10 MBs, the other 2.

Can anyone link to a site where I can find information on how to implement a Dual WAN failover configuration?
 
Starriol said:
Hi guys, I need to set up load balancing for an implementation. We have 2 WAN links, one 10 MBs, the other 2.

Can anyone link to a site where I can find information on how to implement a Dual WAN failover configuration?
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What kind of links? There are different ways that you can do this, but it all depends on your WAN links :D

http://www.cisco.com/en/US/tech/tk648/tk361/technologies_configuration_example09186a00808d2b72.shtml
This will perform a per-session loadbalance with CEF enabled.

If you want something STRICTLY failover, remove the dual-nat route-map and attach the track object(OER) to both static routes via your ISPs.

TDM links will allow you channel bonding, so if we're talking dual T1's or T3's the configuration will be completely different.
 
Considering the 1811 is a fixed router with 2 FastE interfaces and a dial backup, it's probably not TDM :p

Might as well go with OER, moar bandwidth = better
 
Lightworker said:
Considering the 1811 is a fixed router with 2 FastE interfaces and a dial backup, it's probably not TDM :p
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Tu shea good sir! for some reason when I read the thread all I saw in my mind was 18xx... then when you posted I was like "wtf, no... hes using an 1841, 2 WIC/VIC slots". :D

Starriol, you're stuck with the solution that I posted. You can always look into the more manual process too using PBR(for specific types of traffic).
 
With one link on each routed port, the router should have an 8-port switch module for host connectivity
 
You misunderstood. I'm asking what he would use to load balance across unequal links. I wasn't aware that you could do that with OER, if so, post a link or some config cause I can't think of a way to do it.

Edit: Evidently I worded this wrong. I get the technology you're suggesting. My question, or point really, is that this will be suboptimal traffic flows. You will have a 50/50 shot of being on a 5x slower link, which is not an ideal situation. Yes, PBR is an option, but that becomes a huge PITA if you have too many categories of traffic.
 
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Vito_Corleone said:
You misunderstood. I'm asking what he would use to load balance across unequal links. I wasn't aware that you could do that with OER, if so, post a link or some config cause I can't think of a way to do it.
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Look at the link that I posted dude, Wes also made a walkthrough that you commented in yourself a few weeks back. I also told you to implement this(sub automatic loadbalancing) when you wrote your NAT article months ago :p

The loadbalance is per-session, every other session is NAT'd out the next interface. You can disable CEF for a true round robin loadbalance but may encounter countless packet routing issues.
 
xphil3 said:
Look at the link that I posted dude, Wes also made a walkthrough that you commented in yourself a few weeks back. I also told you to implement this(sub automatic loadbalancing) when you wrote your NAT article months ago :p

The loadbalance is per-session, every other session is NAT'd out the next interface. You can disable CEF for a true round robin loadbalance but may encounter countless packet routing issues.
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Right, I know how to load balance (and I've done it before). This is unequal bandwidth though, wouldn't it be load balancing evenly across the links? Which would be a bad thing.

Also, I commented on Wes's post because I had just explained to Calvin how to accomplish it, which I think I told you about. So I don't see how you think I've forgotten how to configure this stuff in a week...
 
Vito_Corleone said:
Right, I know how to load balance. This is unequal bandwidth though, wouldn't it be load balancing evenly across the links? Which would be a bad thing.

Also, I commented on Wes's post because I had just explained to Calvin how to accomplish it, which I think I told you about. So I don't see how you think I've forgotten how to configure this stuff in a week...
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Clearly you dont understand it, and no... I told you about how to do this MONTHS before Wes thread and your conversation with Calvin. Again, bandwidth doesn't come into play here. EACH session is divided equally across each link regardless of bandwidth(this is also what Wes showed in his thread). If you want per-packet loadbalancing then you must disable CEF(which 99% of people dont realize, which is clarified in Wes's thread)

So you can understand:

1. www.google.com
2. Goes out first connection, all subsequent packets for that FLOW are directed out that link.
3. www.hardforum.com
4. Goes out first connection, all subsequent packets for that FLOW are directed out that link.

Understand now? Stop thinking routing protocols and how they loadbalance. No metrics here, just a static route based on a static AD value.
 
Oh boy, here we go. Yes dude, you mentioned load balancing NAT months ago, cookie?

The sessions are divided EQUALLY (as you said) across each link, that is my point. That is suboptimal if one link is 5x faster than the other. You disagree?
 
Vito_Corleone said:
The sessions are divided EQUALLY (as you said) across each link, that is my point. That is suboptimal if one link is 5x faster than the other. You disagree?
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Ill summarize our AIM convo here for the OP so he is aware. I agree with you that it may be suboptimal in some cases, and more often then not you would have a 50/50 chance of sending *more* traffic over a slower link. This is the nature of why NAT loadbalancing is kind of shitty but thats what the way it is.

OP, depending on how much traffic per-stream you may be suboptimally sending traffic out the lower speed link. Like I originally suggested in this thread, you may want to think about tracking and PBR.
 
I edited my post so it's (hopefully) clearer. My opinion is that the 2mb circuit should be a backup and not load balanced.
 
Lol, when you guys argue, it always turns out to be a great learning experience for me... so, fight, fight, fight! :p

Now if you'll excuse me, I'm going back to the 6 new browser windows I have open on load balancing. :)
 
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they sound like a married couple....:rolleyes::p

anyway, depending on the needs of the persons using the links determines the decision to load balance or failover the 2Mb link....this is basic network design people...ASK QUESTONS, what does the business want/need from the infrastructure. our jobs as the network admins/designers is to interpret the business model and determine what can be done with/to the network to get as closely accomplished what needs done.
 
B1zz said:
they sound like a married couple....:rolleyes::p
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LOL, you have a point there.

B1zz said:
anyway, depending on the needs of the persons using the links determines the decision to load balance or failover the 2Mb link....this is basic network design people...ASK QUESTONS, what does the business want/need from the infrastructure. our jobs as the network admins/designers is to interpret the business model and determine what can be done with/to the network to get as closely accomplished what needs done.
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You're absolutely correct about network design(asking questions), but he is not asking for design support. I asked the only question necessary in this situation, anything else would have been redundant and a non-issue question.

Also, good design support involves information and options, which he got(more than he needed im sure). In regards to the business model, again, he came looking for failover solutions, so the decision was already made.

just my .02

Starriol, what are you planning to go with?
 
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