Cisco router failover or load balancing for internet connection.

[Pejayuk]

We need to make our Internet connection more reliable, I would like to implement a failover or load balancing solution. We have a 2mb wireless connection and thinks of getting a 2mb ADSL as a backup. We currently have a Cisco 1700 router.
My questions are;
A) Is it possible to have one router load balancing using the two internet connections and then if one goes down the other will keep going?
B) Is it possible with more than one router?
C) Will the Cisco 1700 router be able to do the job?

Many thanks in advance

Pejayuk

 

[pmesjar]

A) Yes it can be done, eg. using two static default routes, one will be pointing to ISP on the other side of wireless connection and the second will be pointing to ISP on the other side of ADSL connection.
B) It is possible with more routers. You just need to make sure that any router you need to implement has two exact same routes in its routing table with same metric but different next-hop routers - one pointing to wireless ISP, the second pointing to ADSL ISP.
C) It will based on how many users will be connected to the box and how many other features you need to configure.

Peter Mesjar
CCNA, A+ certified
pmesjar@centrum.sk

 

[baddos]

Do you host an email server or webserver on your network?

 

[pmesjar]

Not right now. What do you need?

Peter Mesjar
CCNA, A+ certified
pmesjar@centrum.sk

 

[Pejayuk]

We host both exchange and SQL server on the network. The SQL server is a part of our website that is mainly hosted externaly.

 

[Liesl]

Hi, just wanted to suggest the Radware Linkproof box. We use that - it allows for up to 4 additional internet connections from different ISPs and does load balancing seamlessly between them. Additionally, it also handles any issues that would be generated by different international IPs being advertised for your company..so traffic can go out on one link and come back in on the other. It also determines best route to get to a particular IP. We have had it in for more than a year and have had no problems.

 

[pmesjar]

Everything that has to do with load balancing can be done by playing around a little bit with routes in router's routing table, like adjusting metrics. Once the router has two to four routes pointing to the same destination via different next-hop routers, it will automatically load-balance per-destination. In case you are using EIGRP you can even do unequal cost load-balancing, that is load balance among paths with unequal metrics.

Or use PBR (Policy based routing) and say this half of the users will go this way, the other half will go that way. Anyway this will slow down your router because of additional checking of source addresses (or interface).

Peter Mesjar
CCNA, A+ certified
pmesjar@centrum.sk