Two different ISP's 1 single router with 2 WIC's

[Anand Narayana]

Hi,

we have 2 different Internet Service Providers, what if i plan to have both the ISP's on a single router with 2 WIC's? how good is that? because a default route will be pointing towards the internet like "ip route 0.0.0.0 0.0.0.0 serial 0". in this scenario if 2 ISP's are there 1 on S0 & the other on S1, how would they route the internet traffic? assume that, i wanted 1 private network IP address to go via S0 & the other private IP address via S1 r else equally distribute the internet traffic say load sharing, it is possbile? i have got Cisco 1700 series router.

[amit-singh]

Hi Anand,

You can have both the ISP's on the same router. The only limitation that you will have is that the router will be a single point of failure. You can use PBR on the router to accomplish this. You can have subnet A to go from ISP1 and subnet B to go from ISP2. This way you can always keep the other link as backup in the route map so that if any ISP links fail all the traffic will go via another link.

HTH, Please rate if it does.

-amit singh

[Anand Narayana]

Thankz for the reply Amith, any configuration or document related to this, so that i can configure on a trial basis after my working hours.

[amit-singh]

Hi Anand,

I have myslef configured it anumber of times for different customers.

Please see the link below and extract the useful pbr info out of it.

http://www.cisco.com/en/US/tech/tk364/technologies_configuration_example09186a0080211f5c.shtml

HTH, please rate if it does.

-amit singh

[Anand Narayana]

Hi Amith,

my exact requirement as follows

ISP-1---->Internet Router------->ISP-1 Public IP pool

ISP-2---->Internet Router------->ISP-2 Public IP Pool

"ISP-1" & "ISP-2" are connected to the same "Internet Router" & the public IP's provided by both the ISP's will be used in my office for running webserver/ftp/mail etc...... is that possbile?

Specification :- Router Cisco 1700 Series having 2 WIC & 1 Fastethernet.

is that possible?

[amarsjoshi]

Anand,

Looks like you just want to know that if you have two routes as below :

ip route 0.0.0.0 0.0.0.0 s0

ip route 0.0.0.0 0.0.0.0 s1

will it load balance ?

It will load balance all traffic going out that box thru the s0 and s1.

Also, I dont understand "private address" -- how do u plan to send traffic to private addresses thru the ISP links -

Again assuming you just want to load balance outbound traffic, you should be able to do that without PBR.. Amit, let me know if I am wrong..

HTH,

Amar

[jackyoung]

I will prefer to use PBR for the only private address which use ISP 1 for out-going.

For the NAT issue, it depends on the route-map you configured and the traffic pass through which interface then it will use which NAT pool. There should be no problem for return traffic, it was because you are using that ISP's public address and the return traffic will coming back from same ISP and interface.

If you use two static route, then it will be load-sharing two links but not able to control what traffic to which ISP.

Hope this helps.