Re: NOOP

I think the bigger question is:
Why does it need to be larger than 6 bytes (N+O+O+P+CR+LF)?

What is the remote sending in a NOOP?

Jim Harrison
MCP(NT4, W2K), A+, Network+, PCG
http://isaserver.org/authors/harrison/
Read the books!
----- Original Message -----
From: "Deus, Attonbitus" <Thor@xxxxxxxxxxxxxxx>
To: "[ISAserver.org Discussion List]" <isalist@xxxxxxxxxxxxx>
Sent: Monday, June 24, 2002 12:03 PM
Subject: [isalist] NOOP


http://www.ISAserver.org



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Greetings:

By default, the SMTP filter disables "NOOP," the No Operation
command.  This has never been a problem for our inbound mail, AFAIK.

However, a client our ours using Exchange 5.5 has always received a "Host
unreachable" NDR from their exchange server when mail was delivered to us.

I cleared the logs, and immediately upon testing (when they would send an
email) i would see the Unsafe SMTP Command event for NOOP.  I enabled it
for 6 bytes (the default) and immediately got a "exceeded length" error
(their NOOP was buffered by spaces and 30 bytes).  After increasing to 35
bytes (to be safe) the mail from them now delivers normally.

The question is this:  Has everyone using the SMTP filter enabled
NOOP?  Have you increased the size?  I know of no NOOP security issues, so
why is NOOP disabled by default?  Inquiring minds want to know.

Thanks.

AD


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