Re: mails not going thru'

[Jason Opperisano <opie@817west.com>]

On Sat, May 07, 2005 at 10:14:49AM +0500, varun_saa@vsnl.net wrote:
> *filter
> :FORWARD ACCEPT [0:0]
> :INPUT DROP [0:0]
> :OUTPUT ACCEPT [0:0]
> -A INPUT -s 127.0.0.1 -j ACCEPT
> -A INPUT -p tcp -m tcp -i eth1 --dport 3128 --sport 1024:65535 -j ACCEPT
> -A INPUT -p udp -m udp -i eth1 --dport 3128 --sport 1024:65535 -j ACCEPT
> -A INPUT -s 62.0.0.0/255.0.0.0 -i eth0 -j REJECT
> -A INPUT -p tcp -m tcp -s 217.81.0.0/255.255.0.0 -i eth0 -j REJECT
> -A INPUT -i eth0 -j DROP
> -A INPUT -p tcp -m tcp -i eth1 --sport 80 -j DROP
> -A INPUT -m state -i eth1 --state ESTABLISHED,RELATED -j ACCEPT
> -A FORWARD -m state --state ESTABLISHED,RELATED -j ACCEPT
> -A FORWARD -p tcp -i eth1 -o eth0 --dport 25 --sport 1024: -j ACCEPT  --syn 
> -A FORWARD -p tcp -i eth1 -o eth0 --dport 110 --sport 1024: -j ACCEPT  --syn 
> -A FORWARD -p tcp -i eth1 -o eth0 --dport 1863 --sport 1024: -j ACCEPT  --syn 
> -A FORWARD -p tcp -i eth1 -o eth0 --dport 5050 --sport 1024: -j ACCEPT  --syn 

the policy of your FORWARD chain is set to ACCEPT, so even if there's
traffic you haven't accounted for in these rules--it will still be
allowed through.  you have a rule that allows SMTP (TCP 25) out--so i
bet if you type:

  telnet 64.233.185.27 25

which is the IP of gmail's preferred MX, you'd get connected.  if you're
FORWARD policy was DROP, i'd say that the reason you can't send mail from
a client machine is because you have no rule allowing DNS traffic out:

  -A FORWARD -i eth1 -o eth0 -p udp --sport 1024: --dport 53 -j ACCEPT
  -A FORWARD -i eth1 -o eth0 -p tcp --syn --sport 1024: --dport 53 \
     -j ACCEPT

but since those packets will be accepted by the chain policy, my only
guess is that you do not have any valid DNS servers configured on your
client machines--on a *nix box:

  cat /etc/resolv.conf

-j

--
"Richie: Mom, uh, I really like Potsy.
 Mrs. Cunningham: Well, Potsy's a nice boy, dear. Why shouldn't you
 like him?
 Richie: No, I mean... I REALLY like Potsy.
 Mr. Cunningham: We heard you the first time, son, you've got a
 homosexual attraction to Potsy."
        --Family Guy