[nos-bbs] smtp gateway command

Michael Fox - N6MEF n6mef at mefox.org
Wed Mar 16 13:33:17 EDT 2011

Ooops.  I take that back.  "smtp usemx no" DOES work.


>From looking at the tcpdump of the tunnel between JNOS and Linux, I can see
that the query from JNOS *IS* an A record query.  It's just that the
provider keeps rotating the addresses, much like they do for mail.  So,
never mind.


The time out is still annoying, though.  :-) 





From: nos-bbs-bounces at tapr.org [mailto:nos-bbs-bounces at tapr.org] On Behalf
Of Michael Fox - N6MEF
Sent: Tuesday, March 15, 2011 11:04 PM
To: 'TAPR xNOS Mailing List'
Subject: Re: [nos-bbs] smtp gateway command


Also, "smtp usemx no" doesn't seem to work.


Even though this is set, I can see JNOS trying to contact the MX hosts for
the destination address in the email.  It shouldn't be doing that if usemx
is "no".





From: Michael Fox - N6MEF [mailto:n6mef at mefox.org] 
Sent: Tuesday, March 15, 2011 11:01 PM
To: 'TAPR xNOS Mailing List'
Subject: RE: [nos-bbs] smtp gateway command


I could live with that ("smtp direct off") although I think the other
options might suite some particular situations.


Also, this timeout situation is REALLY, R-E-A-L-L-Y irritating for a gateway
that serves more than its local (same host) JNOS system.  Lots of extra (and
useless) over-the-air traffic clogging the channel as JNOS attempts
connecting to something it will never connect to.  That just shouldn't be





From: nos-bbs-bounces at tapr.org [mailto:nos-bbs-bounces at tapr.org] On Behalf
Of Bob Tenty
Sent: Tuesday, March 15, 2011 9:33 PM
To: TAPR xNOS Mailing List
Subject: Re: [nos-bbs] smtp gateway command


It is annoying and that is also how I filter outgoing port 25, only my smtp
gateway can be reached
from jnos.

For me the choice is simple: if smtp gateway defined, direct off. ( maybe
with a switch for the old behaviour )


On 11-03-15 11:16 PM, Michael Fox - N6MEF wrote: 

It does indeed take quite a bit of time for JNOS to timeout trying to
connect to external servers.


If JNOS is successful reaching a "real" mail server, it typically gets a
reject for doing something wrong.  This causes JNOS to send the message back
to the sender of the message informing of the reject.


So, to prevent that from happening, I disabled forwarding of SMTP on the
tunnel between JNOS and Linux.  This causes the JNOS attempts to reach
Internet mail servers to time out.  At that point, JNOS tries the gateway.


This timeout takes about 2 minutes.  That's kind-of annoying, especially
when you're trying to test a set-up or train people.


So, it seems like an "smtp use-gateway" command which could control JNOS's
gateway usage would be helpful.  The options I originally suggested below
seem good, except I'd change "like-dns" to "non-local".  For completeness,
I'll rewrite it here:


smtp use-gateway { LAST | first | always  | non-local }


smtp use-gateway last   # the default and current behavior; tries direct
and, if it times out, passes to gateway

smtp use-gateway first  # sends to the gateway first and, if that fails,
tries direct

smtp use-gateway only  # sends to the gateway only; does not try to send

smtp use-gateway non-local  # if the host is found in domain.txt, behaves
like "last" (tries to connect directly; otherwise it behaves like "only"
(sends only to the gateway)


Thoughts anyone?  Is this reasonable?  Do-able?







-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.tapr.org/pipermail/nos-bbs_lists.tapr.org/attachments/20110316/d3f9a816/attachment.html>

More information about the nos-bbs mailing list