multihoming issue

[jvalin__s]

Hi guys I have a client who is applying for 2 internet leased line circuits from 2 different ISP's.

I have 2 - cisco 2800 router for the internet connectivity.

I have a L3 switch in the internal zones of the routers.

Both the ISP's have given /30 public network for the wan. I dont have any doubt on that.

But both the ISP's are giving different /28 networks for the internal usage. (for eg to host some servers)

I have 2 - ASA 5510 behind the routers which are going to use public ip addresses given by the ISP's.

The customer wants to use only 1 ISP at a time and if that ISP goes down I should be using the other ISP.

But my doubt is both the pulic ip addresses given by the ISP are of different network subnets and it wont be possible to manually change the IP ADDRESSES ON THE ASA 5510.

Please help me with some solution.

Thanks & Regards,

Jvalin

[paolo bevilacqua]

Yes, as mentioned before, with HSRP and NAT on the router is difficult to balance, so you will have just a primary and a backup.

For some sort of balancing use one router only and the first link referenced.

[jvalin__s]

Hi paolo,

You have cleared all my doubts one last doubt still I am having though.

if I mention the 2 default routes on the ASA's one with default metric and one with a higher metric.

and If I configure sla on the firewall and track the first ISP/ROUTER will it work??

[paolo bevilacqua]

To have the ASA decide on primary/backup links, simply follow the indications in the ASA document linked above.