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Best Practice for Redundant Internet

Hello, Looking for some best-pratice info on providing redundant internet connections and posibly load-balancing across the two connections. Is single provider (Qwest, MCI etc) considered OK or are we best to use two different carrier's. Is BGP the only way to provide the rounting redundancy for both outbound and inbound? Will BGP provide any type of load-balancing across the two lines for inbound and outbound?

Any help would be greatly appreciated.

Blake Frericks

New Member

Re: Best Practice for Redundant Internet

Best practice for redundancy is using 2 different providers, but depending on the area you are in, the provider may just be reselling the local loop so it may not do you much good. The answer on load sharing really depends on your setup, BGP has different options when using multiple routers, multiple providers or just a single router with a single provider.

If load sharing isn't an issue, you can just take advantage of your routers current load sharing uses through CEF. You can load balance per packet or per destination by using static routes pointing to your provider. If you wanted the 2nd line to just be backup, you could use a floating static route. As you can see there is ALOT of info & design details to get into when preparing for such a situation so let us know exactly what your looking for and what you have to work with and we can better guide you.



Re: Best Practice for Redundant Internet

In addition to Adam's reply. I could like to state my opinion.

You can always control the outgoing traffic and not incoming if you are using two ISPs. If you use same ISP, just group two physical connections to one logical link then it is load-balancing.

One or two ISPs are depending on the service availability and the network strategy from your company. If the performance of two ISPs are similiar then it is fine to use two ISPs, if one is good and one is normal, then the normal one may be the backup or specific traffic connection instead of load-sharing.

BGP is using in the Internet, so it is better to use BGP to communicate to the ISP if you require dynamic routing protocol. However, two static route to two ISP / connections is fine.

NAT is another issue that you have to consider when and which NAT pool will be used for which ISP.

Hope this help and Just my 2 cents.

Hall of Fame Super Gold

Re: Best Practice for Redundant Internet

I the past, BGP was the only option for serious internet redundancy and circuit optimization. It often proved painful for the implications of getting an ASN number, setting up the peer with the provider, and managing all correctly.

But with connection tracking feature now the router can now decide which connection to use based on a variety of parameters. You can also apply NAT and firewall at the same time.

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