TCP/IP Config for firewall

[bofhrevenge2]

Hi all, I know this is an ISA post but I’m not entirely sure I’m configuring IP correctly and wondered if someone could advise me.

I have a private network range 10.4.*.* with a router at address 10.4.116.1 all client PC are in the 10.4.117.* range, we have a netmask of 255.255.252.0

I have placed an ISA firewall box directly behind our router (the router is supplied by our ISP and we can't alter it). It has a router facing address of 10.4.116.3 and a LAN facing card of 10.4.116.15.
The ISA seems to think there is an IP config problem, is it not possible for the WAN and LAN cards to be on the same subnet or will I need to configure some static routes?

Any help appreciated.

Thanks.

 

[bofhrevenge2]

I also found this in the event log

ISA Server detected routes through adapter "WAN" that do not correlate with the network element to which this adapter belongs. The address ranges in conflict are: 10.4.116.3-10.4.116.14;10.4.116.16-10.4.119.255;. Fix the network element and/or the routing table to make these ranges consistent; they should be in both or in neither

Any ideas.

 

[ChrisAC]

You can't have the LAN side and the WAN side on the same subnet.

Chris.

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Chris A.C, CCNA, CCSA
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[bofhrevenge2]

Ok cheers.

The odd thing is that it will route internet requests to the internet if i enter our ISP's proxy server but not if i put the ISA as the proxy.