Please see the attached Topology

How many interfaces you have on ISA server ??

If multiple you may try the steps that i have given earlier..

Add routes on ISA server in command prompt

route add 10.1.20.0 mask 255.255.255.0 10.1.40.1 -p
route add 10.1.30.0 mask 255.255.255.0 10.1.40.1 -p
route add 10.1.50.0 mask 255.255.255.0 10.1.40.1 -p

HTH

Hitesh Vinzoda

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I've single NIC on ISA server with following IP

IP: 10.1.40.2/24

G/W: 10.1.40.1

DNS: 10.1.40.3

Assumt that If I add below default route, what will happen ?

route add 0.0.0.0 mask 0.0.0.0 10.1.40.1 metric 10

Here,some routing questions arises in my mind

1. Adding a static route on core switch to forward internet traffice to ISA

2. Adding a default route on ISA pointing to ASA

It can be or cannot.

Please suggest.

One more thing that i want to clarify is that ISA server will be proxy in your network for http, in that case you dont need default route pointing towards ISA. All you have to do is add a default route on switch towards ASA. No routes to be added on ISA as you had configured default gateway under NIC.

The info will flow as below

1. Client will send all http requests to ISA 10.40.x.x which is directly connected to switch on vlan 40

2. ISA server sends the traffic back to Switch based on default gateway

3. Switch uses default route to reach web ip address and sends it to ASA.

4. ASA should have back route for ISA pointing on vlan 50 ip of switch.

This should work...

One more design consideration, you should keep Internet facing devices in DMZ.

HTH

Hitesh Vinzoda

Pls rate useful posts.

Thank you so much That was quite informative. I will try that and let you know.

But I just want only to clarify my doubt that "Is it possible to do in that way i mention in my previous post ? "

I really appreciate it.

1. Adding a static route on core switch to forward internet traffice to ISA

     I assume that static route would be a default route. so Switch will forward all traffic to ISA.

2. Adding a default route on ISA pointing to ASA

     The Next-hop cant be ASA as its not a valid next-hop, the next-hop in your case should be switch. now you have two default routes pointing at each other and it will create a routing loop.

HTH

Hitesh Vinzoda

Pls rate useful posts

Really thanks It was very helpful.

Now its working

I was talking to attached topoloy. It was referred by one of my friend. Please see the attahced