[stunnel-users] Temporary failure in name resolution

[Michal Trojnara]

Phil Wieland wrote:
> I'm running stunnel4 version 4.29 on an Ubuntu server box, using it to 
> tunnel smtp connections to my ISP's mail server.  Everything works 
> perfectly until I reboot the server, when it stops working.
> 
> Apr 24 15:56:11 friedbread stunnel: LOG3[1101:3074997104]: Error 
> resolving 'smtp.blueyonder.co.uk': Temporary failure in name resolution 
> (EAI_AGAIN)

Try the following patch:
ftp://ftp.stunnel.org/stunnel/eai_again.patch
The patch should make stunnel wait for your DHCP to be finished.

> Looking at syslog for boot time, it looks like stunnel tries to resolve 
> smtp.blueyonder.co.uk as soon as it starts, but dhcp hasn't finished at 
> this time so it fails.  It seems to cache something from the failure and

> not try again?  Even though the error is "Temporary".

This "caching" is very interesting indeed.
Could you attach
    strace -f -p <pid_of_stunnel>
, make a connection, and send us the output?  Also try with
    ltrace -f -p <pid_of_stunnel>

Best regards,
    Mike