The
cisco 3620 is capable of exporting the smtp service port 25 to his internal
Exchange IP address. I am doing that here with a cisco 2600. It
works very cleanly and still should not require ETRN.
Set up
this way on his internal network your client would reference a private IP
address such as 192.168.10.10 and on the public IP side of the router, you would
setup host entries and DNS records for the public IP address assigned to the
router that is being exported to the server.
I
would reccomend Cisco's true NAT rather than PAT. We had difficulty with
client computers accessing certain applications on the internet when running PAT
(web browsing and email worked just fine though). The difference is that
in NAT you must have an individual IP address for each client computer assigned
to the router. In PAT all your clients go through a singe IP
address.
-----Original
Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Len Conrad
Sent: Tuesday, August 24, 1999 3:30 AM
To: [EMAIL PROTECTED]
Subject: RE: [IMail Forum] ERTN by Exchange over leased line?
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]]On Behalf Of Len Conrad
Sent: Tuesday, August 24, 1999 3:30 AM
To: [EMAIL PROTECTED]
Subject: RE: [IMail Forum] ERTN by Exchange over leased line?
I don't beleive that exchange has a way of issuing an etrn command inside of it.
From what I've read, at least ver 5.5 fo Exchange can do ETRN.
It also sounds like this issue is getting a little confused. Since you are on a leased line ( I assume it is up 24x7) why use ETRN at all?
Because Exchange on on a private net behind NAT of a Cisco 3620.
My understanding is that ETRN is used by the receiving mail server to say that "Hey, I'm here, I'm online now, start spooling me my mail".
My understanding, too.
The sending mail server then immediately sends all mail for the receiving domain in the queue. This is helpful if you are on dial-up, but with a leased permanent connection should not be neccessary.
As a service to this customer, we do want to relay his mail through our Imail so that if something downstream screws up, we still get his mail until he refloats his boat.
I have a suggestion from [EMAIL PROTECTED] to use PAT, port address translation of port 25, to punch Imail's MX attempted connections through to the private ip address of the Exchange box.
Regards,
Len
