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mails not going thru'

DISCUSSION [email protected] 3 participants 3 messages May 7, 2005

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[email protected]

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#0 lore raw

Hello,
My server is on Mandriva 10.1
eth0 is WAN with static IP connected to 512K DSL eth1 is LAN - 192.168.0.0/24 and 192.168.21.0/24

My rules are as follows :

# Generated by iptables-save v1.2.9 on Fri Jan 7 20:56:35 2000 *nat
:OUTPUT ACCEPT [0:0]
:PREROUTING ACCEPT [0:0]
:POSTROUTING ACCEPT [0:0]
-A POSTROUTING -o eth0 -j MASQUERADE
COMMIT
# Completed on Fri Jan 7 20:56:35 2000
# Generated by iptables-save v1.2.9 on Fri Jan 7 20:56:35 2000 *mangle
:PREROUTING ACCEPT [1024:195745]
:INPUT ACCEPT [1019:194076]
:FORWARD ACCEPT [2:144]
:OUTPUT ACCEPT [1000:192114]
:POSTROUTING ACCEPT [999:192086]
COMMIT
# Completed on Fri Jan 7 20:56:35 2000
# Generated by iptables-save v1.2.9 on Fri Jan 7 20:56:35 2000 *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 -A OUTPUT -p udp --dport 53 --sport 1024: -j ACCEPT
COMMIT
# Completed on Fri Jan 7 20:56:35 2000

Now one problem got solved after chaging but another has started because of that.

-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

Originally sport was set to : --sport 80 I changed to : --sport 1024:65535

after corrections from Jason.

Now I think my mail are not going through which I think is because " 1024 ". Please correct me if I am wrong.

The squid part makes me happy but not the mail part.

What corrections need to be made.

Thanks in advance

Varun

#1 lore raw
Quoted 5 lines

Now I think my mail are not going through
which I think is because " 1024 ".
Please correct me if I am wrong.

The squid part makes me happy but not the mail part.

What system are you trying to connect to when you are sending email?

Grant. . . .

#2 lore raw
In reply to [email protected]
Quoted 7 lines · On Sat, May 07, 2005 at 10:14:49AM +0500, [email protected] wrote:

*filter
:FORWARD ACCEPT [0:0]
:INPUT DROP [0:0]
:OUTPUT ACCEPT [0:0]

(quoted diff) +0 -3
-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

Review

Quoted 10 lines
(quoted diff) +0 -10
-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