Internet link load balancing

Posted on 2006-06-22
Last Modified: 2010-03-19

We are hosting few application servers on DMZ using Cisco PIX firewall. These applications are accessed by the users from Internet. We have one 2 Mbps Internet connection for this purpose. However, due to availability issue of ISP link, we are planning to add second ISP link from different provider. please suggest any economical product available to do inbound and outbound load balancing between two ISP links


Question by:nessmssit
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LVL 77

Accepted Solution

Rob Williams earned 125 total points
ID: 16963232
The Linksys RV042 works very well for this. It will allow you to have 2 independent WAN/Internet connections and automatically balance the network requests over the 2 connections. In the event of a failure it will automatically force all traffic to the working connection. They tend to run about $150-$200 US
Support for this product would also be through Cisco's Linksys division.

Assisted Solution

papimichel earned 125 total points
ID: 16963674
i'm not sure i understood you..
those DMZ servers have valid IP addresses.. right ?
how are those addresses are routed to you ? do you use DSL/Frame relay connection ?
if you do, the suggestion above is not good for you, but anyway be more specific about the use of those servers.. there might be another way to give you better redundancy.

anyway, i don't think there's a way to have the kind of load-balancing that you mentioned..
LVL 77

Expert Comment

by:Rob Williams
ID: 16963906
Good point papimichel, if users are to connect from the outside, names can only resolve to one IP.
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Author Comment

ID: 16969633
Hi Papimichel ,

The servers that we have hosted in DMZ has a private IP addressess which are natted to the Public IP ones given by the Internet Service Provider . The Natting is done on the Cisco-Pix Firewall .We have an internet leased line connection for the internet and the same is terminated on a Cisco ISP Edge router.



Author Comment

ID: 16969711
Hi Rob will,

I have a query regarding two independent ISP connections.

How will the failover happens when the users URL is resolved (by the DNS ) into an public IP of the Internet Link-01 and after that the internet link fails

With Regards
LVL 77

Expert Comment

by:Rob Williams
ID: 16969844
>>"How will the failover happens "
It won't. That is why I mentioned papimichel, had a good point. It is an ideal solution for "inside" users but will not resolve the problem for those on the outside of the firewall. Sorry, I know of no solution that will work in this situation.

Expert Comment

ID: 16973209
in order to have that kind of redundancy you can do something else:
you can point your registered DNS to a dynnamic DNS address that'll map by default to one of the ISP's address. if that line fails, you'll be still online because the other ISP's line is on (that you'll have to configure on your router) thus, the dynamic DNS record'll change its map to the other ISP's ip address, and all users on the outside'll still be able to use your services with your original DNS name.


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