ISA server and DDNS

[Leonardo Broseghini]

I installed an ISA server with 3 NICs (one internal, one external, and one
for DMZ).
The ISA server is configured as a server belonging to and active directory
domain.
The main DNS is internal, and I added the ISA server DNS record (the
internal address, off course).
In this way the PC clients query the DNS server, in order to obtain the ISA
address.
The problem is that sometimes the ISA server force the record table to the
external address, so the clients cannot access internet anymore (they cannot
find the ISA server).
How can I definitely fix the DDNS record ?

Thanks, Leo

 

[Herb Martin]

I installed an ISA server with 3 NICs (one internal, one external, and one
for DMZ).
The ISA server is configured as a server belonging to and active directory
domain.
The main DNS is internal, and I added the ISA server DNS record (the
internal address, off course).
In this way the PC clients query the DNS server, in order to obtain the ISA
address.
The problem is that sometimes the ISA server force the record table to the
external address, so the clients cannot access internet anymore (they cannot
find the ISA server).

Makes no sense if you have made the record MANUAL,
since dynamic registration should not be able to override
that but see below (and I let mine dynamically register
anyway.)

How can I definitely fix the DDNS record ?

Two things to do: Make sure the external NIC
settings do NOT "register this address" and the
internal is set to do so.

I also give the EXTERNAL a different name
suffix, e.g. cable.domain.com or dsl.domain.com
so that if it does register (I let mine) it registers
the address under an obviously external name.

Nice thing about this, is that I can ping that
external name (even from inside) and figure
out the external ISA IP if I wish.

Also, it may help to re-order the NIC bindings
if the problem persists, so that the internal NIC
is bound first.

 

[Leonardo Broseghini]

Two things to do: Make sure the external NIC
settings do NOT "register this address" and the
internal is set to do so.

Thanks, this was the problem.

Leo