Reduant internet with 2 different ISP's.

[r.bhupathi]

Hi

I'm looking at setting up an internet connection with 2 different ISP's for High Availability.

When one goes down we want to stay live as we have a critical application that will be running over the internet.

We have Cisco 1721 Connected to one ISP and CISCO 2801 Connected to Otehr ISP. We have a Nortel Firewall behind this routers and this firewall does the NATTing.

I am attaching a diagram. Can some one help me with this plese.

Regards

Rajendra Prasad Raju.Bh

[ankurbhasin]

Hi Rajendra,

I think HSRP will the best config for you.

You can have HSRP running on your 2 router ethernet interface and can track your serial interface.

I mean you can keep the HSRP priority on your VSNL router high and can track the serail interface and if your serial goes dows the tracking config will reduce the priority of the HSRP and in that case your standby router ethernet interface will come up and I hope that will solve your redundant purpose.

HTH

Ankur

[vm612]

I agree with ankur with one modification.

Use both ISPs and get your money's worth!

HSRP as sugested, but no tracking/monitoring. You will need an additional ethernet interface available on each router for this to work. Connect the 2 routers back to back via ethernet on a new network.

On your "active" router create another equal cost default route pointing to the new ethernet network ip address on the standby router's interface, so when everything is up and operational you will utilize both paths, then if you lose an ISP, interface, or router you still have one path.

[r.bhupathi]

Hi,

I have configured the routes for HSRP and made some modifications for NATting and I am able to go to other ISP when my active link / router is down. But its taking some time about 6 seconds to switch over and traffic is not shifting back once my active path comes up. I need to reduce the time from 6 sec to 1 sec and have to shift back to active once the active link is back.

Regards

Rajendra

[jjadanluengo]

Hi,

Using HSRPv2 in your routers will allow you to reduce the shifting time below 1 second because you can specify millisecond timer values. To switch back to the primary link when it comes back again simply use the ´standby preempt´ command.

Regards,

Juanjo