[TriLUG] help! weird sendmail problem

Mon Oct 7 14:46:41 EDT 2002

Probably a good idea.  I'll go back and re-read that thread about the dynamic 
DNS service to see how I can get that up and running at the house.   I'll try 
to make it to the meeting on Thursday - I just hope I can make it home in 
time for Survivor.

Greg

On Monday 07 October 2002 02:28 pm, you wrote:
> Greg,
>
> A few notes:
>
> 1.  Don't tell folks your hostname/IP.  It's easy enough for them to get
> it, and giving it to them just invites portscans, DoS attacks, and who
> knows what else.
>
> 2.  Use a dynamic DNS service, because your hostname will not change
> that way, and changing an MX record, or your machine's hostname, is just
> a silly thing to have to do on an even semi-annual basis.
>
> I can talk to you more about this on IRC, or else at the meeting on
> Thursday, if you attend.
>
> Regards,
> Ben Pitzer
>
> On Mon, 2002-10-07 at 12:42, Greg Brown wrote:
> > Jason - you are correct, sir.  Here's my machine info:
> >
> > Current IP Address:  66.26.92.247
> > Hostname: rdu26-92-247.nc.rr.com
> >
> > Actually, RR's way of doing this isn't that bad as it seems to have a
> > predictable hostname - assuming I can change the hostname of the box each
> > time my IP address changes.  I've never tried this and I'm certain it
> > will monumentally screw things up, but I'll give it a shot anyway.
> >
> > Paloverde is the current hostname of the box, but that's unresolvable to
> > anyone so I'll try changing the hostname around.
> >
> > Greg
> >
> > On Monday 07 October 2002 11:59 am, you wrote:
> > > unless you are using RR business class, i don't think RR is going to
> > > give what you want.  assuming your user/account name is paloverde, that
> > > doesn't mean that your IP address maps to paloverde.nc.rr.com.  next
> > > time you're at home, try hitting checkip.dyndns.org in a browser, this
> > > will tell you your public IP address and the reverse resolution DNS
> > > name.  in my case (i have earthlink cable service, very similar to RR),
> > > my 'DNS' name is:
> > >
> > > Current IP Address: 24.136.143.105
> > > Hostname: user-0c8h3r9.cable.mindspring.com
> > >
> > > obviously not a very user-friendly DNS name.  note that if you resolve
> > > cerient.net (my domain name that i host from home) you will get my IP
> > > listed above.  if that's what you want, you'll need a dynamic DNS
> > > account which you can get for free from dyndns.org.  then you could
> > > have paloverde.dyndns.org always point to your RR IP address.  so when
> > > you send email from your house to lucent, they can reverse resolve your
> > > domain name in to the actual IP address the mail came from, and accept
> > > your mail
> > >
> > > i think there was a fairly long thread about dynamic DNS a week or so
> > > ago, you might want to check out the archives for more info.
> > >
> > > jason
> > >
> > > > The Facts:
> > > > Red Hat 7.1
> > > > sendmail-8.11.2-14
> > > > connected to my cable modem (outside interface)
> > > > connected to my small networks serving 1 pc (in case RR is listening)
> > > > (inside interface).
> > > >
> > > > My outside interface appears to NOT be able to resolve it's domain
> > > > name. I think this is a RR wide thing.  Is anyone running RR able to
> > > > get a resolvable DNS name on the Roadrunner interface on the RR
> > > > network?  If so how?  For instance, the command (issued from my linux
> > > > box at work) 'dig paloverde.nc.rr.com' does not return an ip address.
> > > >  Does Roadrunner just not update DNS entries or simply not support
> > > > DNS for it's DHCP connected devices?
> > > >
> > > > My real question is this:
> > > >
> > > > Because my outside interface is not DNS resolvable some mail servers
> > > > will not accept mail send from my box, an example of this is my
> > > > employer, Lucent. Saturday, a day which I was not even in town, my
> > > > mail server attempted to send mail to my work address 6480 times!!! 
> > > > And it's been doing this every stinking day.
> > > >
> > > > Upon noticing this I freaked out, then stopped sendmail.  I looked in
> > > > /var/spool/mail and sure enough, there were references to lucent.com
> > > > in the three files in this directory.  I deleted every file in this
> > > > directory then restarted sendmail thinking this would stop the mail
> > > > from going out which had not already been delivered.
> > > >
> > > > No luck.  My machine is still attempting to mail lucent.com and the
> > > > files in /var/spool/mail are still empty.
> > > >
> > > > Any ideas on where to look to get rid of the files that is causing
> > > > this?
> > > >
> > > > Here's an example of what is showing up in my maillog:
> > > > 4:03:18 paloverde sendmail[16406]: g95G0GT14652:
> > > > to=gwbrown1 at lucent.com, ctladdr=root (0/0), delay=16:03:02,
> > > > xdelay=00:00:18, mailer=esmtp, pri=86730161,
> > > > relay=ihemail2.lucent.com. [192.11.222.163], dsn=4.0.0,
> > > > stat=Deferred: ihemail2.lucent.com.: No route to host
> > > >
> > > > Thanks!!!
> > > >
> > > > Greg
> > > >
> > > > _______________________________________________
> > > > TriLUG mailing list
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> > > >     http://www.trilug.org/~lovelace/faq/TriLUG-faq.html
> > >
> > > ------------------------
> > > Jason Tower
> > > Cerient Technologies
> > > jason at cerient.net
> > >
> > >
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> >
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