Date: Tue, 22 Jul 2003 13:10:54 +1000 (EST) From: <keith@smmc.qld.edu.au> To: <ryan@sasknow.com> Cc: Free bsd <freebsd-questions@FreeBSD.org> Subject: Re: Mail delivery wierdness Message-ID: <1344.203.220.88.216.1058843454.squirrel@localhost.smmc.qld.edu.au> In-Reply-To: <20030721181045.I31748-100000@ren.sasknow.com> References: <1201.203.221.153.61.1058830050.squirrel@localhost.smmc.qld.edu.au> <20030721181045.I31748-100000@ren.sasknow.com>
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Hi Ryan... Yep I can confirm it was NOT listening on :25 The techie on the ground swore black & blue it was (always follow what you know!). I figured it wasn't but maybe it was somethjing I didn't understand?? He changed the config on exchange and voila! Now I can chat with smtp on the mail server from outside! Next question. Squid is also on the gateway/firewall. Mail is still not being delivered. Can I assume if I can chat via telnet to the exchange server : 25 Then mail can also get thru? Surely that means a persistent session is set up and mail should also get to it. It isn't being delivered to mailboxes there so what the??? Any ideas? Thanks Keith > keith@smmc.qld.edu.au wrote to Free bsd : > >> Hi all, >> I am trying to connect to an exchange server via my new gateway >> ipfilter fbsd 4.7 ipnat firewall. >> Telnetting to the server inside to port 25 reveals... >> >> Connected to 203.44.yyy.xx >> Escape character is ']'. >> Connection closed by foreign host. >> >> Why would it close instantly? > > That's usually the behaviour indicating that there is a server at > 203.44.yyy.xx, but there is no service listening on port 25. (Or, maybe > your fancy ipfilter firewall is simulating the equivalent). > > The first thing you should do is confirm that the server in question > *is* actually listening on port 25. MS Exchange is pretty far beyond the > charter of this list, but general network techniques would still apply: > > Try the same telnet test using the win32 telnet on the server itself. > (i.e., telnet localhost:25, and try it by the public IP in case Exchange > isn't listening on localhost for some reason). If it won't talk SMTP > with you in either case, you won't get any farther. On the other hand, > if the test is successful, try the same thing from the next hop (your > FreeBSD gateway?). > > If you isolate the problem to the gateway (and/or every host directly > connected to the other side of your gateway), you'd probably do well to > forward your firewall rules and ipnat config to the list (as well as a > description of what you're trying to accomplish with your config), in > which case we'll be able to give you better specific instructions. > >> Does this reveal while I can't send mail to any email account on it? >> Is this an exchange hassle? Is port 25 to be only tcp or udp as well. > > SMTP is a connection-oriented service. SMTP can, in theory, be used > over transport layers other than TCP, but SMTP over UDP would require a > fair hack to SMTP to implement. So, the short answer is, forget about > UDP. :-) > > - Ryan > > -- > Ryan Thompson <ryan@sasknow.com> > > SaskNow Technologies - http://www.sasknow.com > 901-1st Avenue North - Saskatoon, SK - S7K 1Y4 > > Tel: 306-664-3600 Fax: 306-244-7037 Saskatoon > Toll-Free: 877-727-5669 (877-SASKNOW) North America > > > _______________________________________________ > freebsd-questions@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to > "freebsd-questions-unsubscribe@freebsd.org"
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