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Question about CISCO 2800 Series Router

We currently have a Cisco 2800 series router that we are using as a firewall and router for out network.  My question is whether it is possible to have redundant internet connections setup for load balancing and failover if one goes down.  We currently pay a company to manage our Internet and phone system and they are trying to sell us a seperate device to perform this function.  Isn't this possible with the 2800?  Any info about this would greatly appreciated.

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VIP Super Bronze

Re: Question about CISCO 2800 Series Router

Hi Dave,

If you need router redundancy, than you would need another router just like the one you already have with a separate connection to the provider.  If you just need link redundancy, than you can use the existing outer and have a second link to the same provider or a different provider.

HTH

Reza

6 REPLIES
VIP Super Bronze

Re: Question about CISCO 2800 Series Router

Hi Dave,

If you need router redundancy, than you would need another router just like the one you already have with a separate connection to the provider.  If you just need link redundancy, than you can use the existing outer and have a second link to the same provider or a different provider.

HTH

Reza

Community Member

Re: Question about CISCO 2800 Series Router

Reza,

Thanks for the response.  We would only need link redundancy with two different providers.  Can I ask you how reliable the fail over is and if it requires any manual steps to switch things over to the other link?  Does it automatically fail over immediately when the other link goes down?  Also how diffiicult is it to setup?

VIP Super Bronze

Re: Question about CISCO 2800 Series Router

Dave,

The fail over should be pretty fast specially if you are running dynamic protocol like BGP.

I have include this link so you can see how the peering would work with multiple provides using a singe device with BGP.

http://www.cisco.com/en/US/tech/tk365/technologies_configuration_example09186a00800945bf.shtml#conf4

HTH

Reza

Community Member

Re: Question about CISCO 2800 Series Router

Excuse me for being somewhat of a novice at this but how does this handle the different IP addresses.  We host a website and also have inbound email and VPN connections.  Is it possible to keep the public IP the same?  If it switches over to the new link with a different provider would it have a different IP?

Hall of Fame Super Gold

Re: Question about CISCO 2800 Series Router

Dave

For a novice you did an excellent job of identifying the biggest difficulty in providing redundancy for Internet connections. I find it helpful to think about providing redundancy for traffic originated within your network (going out) separately from providing redundancy for traffic originated outside your network (coming into your network). The first part is pretty easy - you provide routing information that uses the link to one provider, most often a default route, and you provide routing information that uses the link to the other provider, again most often another default route, and you provide some failover mechanism. The failover mechanism may be running BGP as suggested by Reza or it might be a floating static default route, or it might be some other mechanism.

The second part can be quite challenging. When you have address space that you use that is given by one provider and then you establish an Internet link with another provider the challenge becomes how to devices in the Internet identify you and how do they get to you in the event of a failure of the first provider. You may have a path to the Internet and the Internet may have a path to youi, but how do they know that the hosted web site, or the email server that uses addresses from the first provider is available using the alternate path. There are a couple of options which may work, depending on the local circumstance: 1) there might be a solution using DNS and making changes in the DNS so that names resolve differently  when there is a problem with the first provider 2) you might negotiate and ask permission to advertise the address space you use (from the first provider) out the link of the second provider. 3) you might get some kind of proxy/balancer that becomes the target for your server addresses and knows how to forward the traffic to you using either of the links.

I will also observe that if the concern is failure of the primary link that you can get link redundancy by provisioning a second link from the same provider (especially if they can give you some geographic diversity for the links). With links from the same provider there is no issue about using a different IP address space when you go out the second link.

HTH

Rick

Community Member

Re: Question about CISCO 2800 Series Router

Is there any Dynamic DNS systems that you are aware of?  Something that would change our DNS records in

the event the one IP went down?

Also I think I'd rather use two providers,because I would assume there would a risk of both links going down if the problem was local.  We were thining of a business class cable or FIOS connection as a backup.

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