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iptables as gateway and POP3 SMTP ports

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http://serverfault.com – when trying to open the ports 110 and 25 in my iptables for outlook-only users, i cant do it except by forwarding as such: -I FORWARD -i eth0 -s 192.168.1.0/24 -j ACCEPT -I FORWARD -i eth1 -d 192.168.1.0/24 -j ACCEPT but doing so allows the rest of the users in my lan to bypass my squid proxy. whats the proper syntax for these forwarding commands to just pen ports 110 and 25? my iptables -L output is: Chain INPUT (policy DROP) target prot opt source destination ACCEPT all -- anywhere anywhere ACCEPT all -- anywhere anywhere (HowTos)

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Submitted by dayu on 03/09/2012 – Made popular on 03/09/2012

Stories similar to iptables as gateway and POP3 SMTP ports

IPTables is running on my web server. I really need SSH dynamic port forwarding, but my IPTables DROP any INPUT/OUPUT connection, only allow some ports.

For FORWARD chain, I wrote these rules:

Chain FORWARD (policy ACCEPT) target prot opt source destination DROP tcp -- 0.0.0.0/0 0.0.0.0/0 tcpflags:!

I used an online tool to create an iptables firewall. Basically I just need port 22 and 1194 open to the outside world. But I noticed this bash script has input, forward and output chains as accept by default. Is it blocking all traffic but those two ports? Thanks.

I have the follwing iptables rules:

Chain INPUT (policy DROP) target prot opt source destination ACCEPT tcp -- anywhere anywhere tcp dpt:ssh ACCEPT tcp -- anywhere anywhere tcp dpt:http ACCEPT tcp -- anywhere anywhere tcp dpt:https ACCEPT tcp -- localhost.localdomain anywher

Binding IPs to non-root users 34 weeks 3 days ago

I want to bind IPs to non-root users so that all outgoing applications will use that IP for the user.

I'm trying to find out why changing my default iptables policy is affecting what nmap sees when it scans my host.

Consider the following iptables setup:

iptables -F iptables -A INPUT -p tcp -s 10.1.0.0/20 --dport 22 -j ACCEPT

iptables -P INPUT ACCEPT iptables -P FORWARD DROP iptables -P OUTPUT ACCEPT

iptables -A INPUT -i lo -j ACCEPT iptables -A INPUT -m state --state ESTABLISHED,RELATED -j AC

Gcool wrote:Plain old iptables will do just fine.

Hey guys,

I don't understand whats going on with my rootserver... I have reset iptables and just opened the port for ssh. Now suddenly over night I see that there are a various of ports open: 21,80, 135, 139, 445, 3128

Could it be that vsftpd for example put rules in automatically to allow input on port 21?

I also tried disabling iptables with this command:

Code: # iptables -X # iptables

I have these iptables rule.

I currently installed openvpn on CentOS 6 64bit and everything is working fine but I want to portforward a client "user" so they can use that port.