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SMTP connection failure message - 9.Aug.2004 9:58:00 PM

BobW

Posts: 227
Joined: 27.Mar.2002
Status: offline

I have noticed a number of connection failures from external SMTP servers to our ISA server which acts as our SMTP gateway.

The message is:
0xc0040017 FWX_E_TCP_NOT_SYN_PACKET_DROPPED

Any thoughts?

Thanks,
Bob

[ August 09, 2004, 09:58 PM: Message edited by: BobW ]

Post #: 1

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RE: SMTP connection failure message - 10.Aug.2004 5:20:00 AM

tshinder

Posts: 50013
Joined: 10.Jan.2001
From: Texas
Status: offline

Hi Bob,

Any mail being missed? Could the ISA firewall just be port scanned?

Thanks!
Tom

(in reply to BobW)

Post #: 2

RE: SMTP connection failure message - 10.Aug.2004 5:54:00 AM

BobW

Posts: 227
Joined: 27.Mar.2002
Status: offline

Anyone else see these in your logs?

Hard to say if any email is being missed. I was using the new logging system (It is ALLOT BETTER than the ISA 2000 logging) when I noticed these. I will look back in my email logs and cross reference the times.

Interestingly enough, I am NOT using the SMTP part of ISA, but am running the Symantec gateway 4.x. I then publish the SMTP server on the ISA box (I used to use a packet filter on the prior ISA version)....from what I gather the errors I am seeing are before the SMTP server sees the traffic.

As always, thanks,
Bob

quote:
Originally posted by tshinder:
Hi Bob,

Any mail being missed? Could the ISA firewall just be port scanned?

Thanks!
Tom

(in reply to BobW)

Post #: 3

RE: SMTP connection failure message - 11.Aug.2004 2:20:00 PM

tshinder

Posts: 50013
Joined: 10.Jan.2001
From: Texas
Status: offline

Hi Bob,

Is the Symantec piece running on the ISA firewall?

Or is this a separate box?

Thanks!
Tom

(in reply to BobW)

Post #: 4

RE: SMTP connection failure message - 11.Aug.2004 5:33:00 PM

BobW

Posts: 227
Joined: 27.Mar.2002
Status: offline

It is running on the ISA box. I have been doing this since way back on the the previous version of ISA with a packet filter. Works quite well.

The Symentac gateways turns away a host of bad connections, viruses etc. Allows more advanced filterin, nice reporting etc. I figure the more viruses/garbage I can keep away from my Exchange server the better even though I have AV on it as well.

It does not utilize the MS SMTP server but rather it's own.

BTW, the dropped connections are showing on the ISA logs, but there are no corresponding SMTP errors, connections, drops, etc. So I guess the firewall is doing it's job!

I am curious, however, what it means exactly....

Thanks, as always,
Bob

Originally posted by tshinder:
Hi Bob,

Is the Symantec piece running on the ISA firewall?

Or is this a separate box?

Thanks!
Tom[/QUOTE]

(in reply to BobW)

Post #: 5

RE: SMTP connection failure message - 31.Jan.2005 8:08:00 PM

Christ5340

Posts: 7
Joined: 1.Jun.2003
Status: offline

I am having similiar problems. My ISA server 2004 is dropping random SMTP packets and users are losing those emails. Has anyone come up with why or has MS said this is an "issue"

(in reply to BobW)

Post #: 6

RE: SMTP connection failure message - 31.Jan.2005 8:14:00 PM

penrose.l@2college.nl

Posts: 474
Joined: 29.Jan.2004
From: Netherlands
Status: offline

TCP NOT SYN = bad network ruleset. Check your ROUTE rule it should be NAT or the opposite can't remember.
<wished this was a sticky [Smile]

>

LexP

(in reply to BobW)

Post #: 7

RE: SMTP connection failure message - 9.Feb.2005 2:40:00 PM

bkrstudio

Posts: 3
Joined: 3.Feb.2005
Status: offline

Has anyone resolved this issue??? I'm having the same problem. Dr. Shinder suggested increasing the connection limit to the mail server. I've done that but I'm not sure that it has resolved the problem... maybe I haven't raised it high enough???

(in reply to BobW)

Post #: 8

RE: SMTP connection failure message - 18.May2005 5:09:00 PM

Guest

nobody has the answer, Richard does [Smile]

disable the f.....g SMTP Filter (under Add-ins), now it'll work.
ISA 2000 had the same bug, bleh, now it cost me twice half a days [Wink]