Dual ISP load balance and backup for each other

[cole xu]

Hello,

I have two ISP circuits and the following devices in hand:

1.   Cisco ASA 5510

2.   Cisco 2800 router

3.   Cisco 3750 switch

I've finished a part of the configs on above equipments, please refer to the attached diagram.

And I'm making a test in order to achieve the below features:

1. By default, packets from PC1 go out through ISP 1. Packets from PC2 go out through ISP 2

2. When ISP 1 is down, packets from PC1 changed its way to ISP 2 through the 2800 router. And when ISP 2 is down, Packets from PC2 changed its way to ISP 1 through ASA 5510.

I'm not sure what to make on the above devices to achieve these functions. please help point out what configs need to make. Thanks!

[sean_evershed · Accepted solution]

If you had a spare interface on your router it might be worth considering a re-design of your network based on this link:

https://supportforums.cisco.com/docs/DOC-13015

It has the advantage that traffic destined to both ISPs pass through a firewall. In your current design only traffic destined to one ISP is protected by a firewall.

As an alternative see this link below for configuring redundant ISPs. ith this option you could remove your router from your network and use it for another task.

http://www.cisco.com/en/US/products/hw/vpndevc/ps2030/products_configuration_example09186a00806e880b.shtml

[cole xu]

Thanks for your suggestions, I've just completed this test.  I made some router policy on the 3750 core switch and can achieve the features as I want.