RE: [cobalt-users] sendmail delivery failure through IPChains

[Francois Thomas <FrancoisT@xxxxxxxxxxxx>]

> -----Message d'origine-----
> De : Charles Williams
> [mailto:hosting.mailing.list.account@xxxxxxxxxxxxxxx]
> Envoyé : jeudi 12 juillet 2001 11:51
> À : cobalt-users@xxxxxxxxxxxxxxx
> Objet : [cobalt-users] sendmail delivery failure through IPChains
> 
> 
> hey all,
> 
> I have searched the archive and haven't found a solution to 
> this problem.  I
> recently installed IPChains using the script below.  The 
> problem is that all
> mail sent is being refused by the destination servers.  I can 
> telnet from my
> raq to the destination SMTP servers but sendmail is 
> continualy deferred.  I
> can find nothing wrong with the firewall and since I CAN telnet to the
> remote smtp server I am inclined to think the script is ok.  
It is not so simple. You should look for some documentation about firewalls,
protocols, ports, ....

> Any ideas?
First of all, DO NOT POST YOUR FIREWALL CONFIG HERE !!!
If I were you, I would be crossing my fingers now, hoping that nobody will
use it for hacking me :-(

Second, you can at least solve your mail problem (I think) by putting this
lines in the STMP section of your script:

ipchains -A input  -i $EXTERNAL_INTERFACE -p tcp --source-port 25 -d $IPADDR
$UNPRIVPORTS -j ACCEPT
ipchains -A output -i $EXTERNAL_INTERFACE -p tcp -s $IPADDR $UNPRIVPORTS
--destination-port 25 -j ACCEPT

>     # SMTP server (25)
>     # ----------------
>     ipchains -A input  -i $EXTERNAL_INTERFACE -p tcp  \
>              --source-port $UNPRIVPORTS \
>              -d $IPADDR 25 -j ACCEPT
> 
>     ipchains -A output -i $EXTERNAL_INTERFACE -p tcp ! -y \
>              -s $IPADDR 25 \
>              --destination-port $UNPRIVPORTS -j ACCEPT

Hope this helps...
Regards
François THOMAS