Re: sendmail Broken Pipe Error

From: John-Mark Gurney <jmg_at_funkthat.com>
Date: Wed, 26 Mar 2014 09:20:35 -0700
Willy Offermans wrote this message on Wed, Mar 26, 2014 at 12:17 +0100:
> On Tue, Mar 25, 2014 at 09:43:16AM -0700, John-Mark Gurney wrote:
> > Willy Offermans wrote this message on Tue, Mar 25, 2014 at 11:39 +0100:
> > > I'm not an expert in tcpdump. Can anyone make sense out of the messages?
> > 
> > If you dumped the contents, using -s 0 -X, and look at that last packet
> > you should see 0d 0a 2e 0d 0a at the end..  which is CR/LF/./CR/LF.. If
> > you don't see that, then for some reason sendmail/FreeBSD isn't telling
> > the server that it's done sending which would prevent the receiving
> > side from ack'ing the email causing the timeout...
> 
> I followed your suggestions. However I'm not able to distinguish the last
> packet. Is there a way to find this with help of the Flags? The following
> is the output of tcpdump -r /root/tmp/tcpdump -X | grep Flags
> 
> 11:57:56.539788 IP MyServer.com.41115 > Smarthost.com.smtp: Flags [S], seq 1001452351, win 65535, options [mss 1448,nop,wscale 6,sackOK,TS val 407239960 ecr 0], length 0
> 11:57:56.555262 IP Smarthost.com.smtp > MyServer.com.41115: Flags [S.], seq 1277075046, ack 1001452352, win 8192, options [mss 1452], length 0

It should look something like:
09:18:34.723280 IP jmgmac.funkthat.com.64724 > h2.funkthat.com.ssh: Flags [.], ack 177, win 33280, options [nop,nop,TS val 1854905469 ecr 3482476972], length 0
        0x0000:  4510 0034 d7ac 4000 4006 e1af c0a8 0003  E..4.._at_._at_.......
        0x0010:  c0a8 0004 fcd4 0016 7e48 238e d872 43dc  ........~H#..rC.
        0x0020:  8010 8200 7c08 0000 0101 080a 6e8f 9c7d  ....|.......n..}
        0x0030:  cf92 61ac                                ..a.

Notice the hex output...  I didn't see any of that in your output...
The last packet I was talking about is the last one that had length
1448 that your server sent...

-- 
  John-Mark Gurney				Voice: +1 415 225 5579

     "All that I will do, has been done, All that I have, has not."
Received on Wed Mar 26 2014 - 15:20:38 UTC

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