Mapping an Internal Address to an External One

[BrotherJones]

hello.
I have isa server at the perimeter. It's external interface has a block of addresses from 66.x.x.210 through 66.x.x.215
66.x.x.210 is the first address assigned to the external interface so that this is the address used by all internal clients when they are accessing resources on the internet.
I assigned 66.x.x.215 to an internal exchange server (internal address is 192.168.1.11)

When the exchange smtp service sends mail, it connects to other smtp servers at 66.x.x.210 rather than 66.x.x.215.
I understand why it does this, but am wondering if there is a way to force my exchange server to use 66.x.x.215 when it accesses the outside world. I'm guessing I just need to establish a mapping on the isa server. (I need to do this for reverse lookup reasons).

Many thanks.

 

[InfrArch]

If I understood you correctly, you'd like to force ISA to send outbond packets by using different (Second) IP address when the packet comes from exchange.
In ISA - it's not possible. Neither of ISA versions supports this type of IP mappings.

ISA will use diffrent IP address as an outbong IP (if you have NAT relationship implemented, of course) only if it will receive an inbound packet to this IP, so then the outbond IP will be the same (Exchange publishing scenario).



Victor K (Microsoft Consulting Services)
MCSA/MCSE:Security & Messaging;CNE;CCSE+;CIWSP;CIWSA;Network+;CCNA;nCSE;CISSP