Re: TCP/IP filter & SMTP

From: Ken Schaefer (kenRMV@THISadOpenStatic.com)
Date: 09/10/02 

From: "Ken Schaefer" <kenRMV@THISadOpenStatic.com>
Date: Tue, 10 Sep 2002 17:50:21 +1000

What if you install some kind of packet sniffer and capture the packets
going back and forwards? This will tell you what port you'll need to
open. -or- install a software application level firewall and see what it
pops up (TPF is a good choice: www.tinysoftware.com)

Also, if you are using MS SMTP server or Exchange server, you'll need to
enable TCP 53:
http://support.microsoft.com/default.aspx?scid=kb;en-us;Q263237

Cheers
Ken 

--
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
"sharky" <sharky@nospam.com> wrote in message
news:ez3lCKHWCHA.1632@tkmsftngp11...
> I have enabled TCP/IP filter on all addresses on my web server (yea me).
>
> I've got everything working except the UDP filter. I denied access to all
> UDP services except 88,137,138,53,135 which allows me to browse my network
> connection to shares, resolve dns, and use RPC - BUT for some reason, my
web
> server can no longer find my ISP's SMTP server to send mail from our asp
> formmail. I get the following error:
>
> WSAHOST_NOT_FOUND
>
> That doesn't seem right because I've got SMTP (TCP) enabled on TCP, and
DNS
> (53) enabled in UDP, and I can't find any other ports that SMTP might use.
>
> If I enable all UDP ports, it works fine. When I deny all UDP ports except
> the above, it breaks, so it must be some UDP port is needed to use SMTP
from
> my web server.
>
> NOTE: this ONLY happens when I turn off UDP ports, and yes I have enabled
> SNTP ports on TCP, but that doesn't appear to be the problem because I
only
> have this problem when I deny UDP ports.
>
> Has anybody run into this before or have some knowledge on the subject
they
> can share?
>
> Gracias!

Relevant Pages

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  • Re: TCP/IP filter & SMTP
    ... >> Open up all the ports so that it works. ... >>> server is idle as when I sent mail from the site. ... >>> some sort of UDP packet when I send mail. ... >>> when I close UDP ports. ...
    (microsoft.public.inetserver.iis.security)