computers:firewall_configuration
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Table of Contents
Firewall configuration
iptables masquerading
First enable IPv4 packet forwarding by editing /etc/sysctl.conf
, uncomment (or add) the following line:
net.ipv4.ip_forward=1
Then add the following lines to /etc/rc.local
(so the rule is enabled on reboot):
# enable masquerading Ext_IF="eth0" Int_IF="eth3" iptables -t nat -A POSTROUTING -s 192.168.1.0/16 -o $Ext_IF -j MASQUERADE iptables -A FORWARD -s 192.168.1.0/16 -o $Ext_IF -j ACCEPT iptables -A FORWARD -d 192.168.1.0/16 -m state --state ESTABLISHED,RELATED -i $Int_IF -j ACCEPT
Forwarding
# forward ssh to workstation with the internal ip 192.168.1.2 Int_IP="192.168.1.2" iptables -t nat -I PREROUTING -p tcp -i $Ext_IF --dport 22 -j DNAT --to-destination $Int_IP:22 iptables -A FORWARD -i $Ext_IF -o $Int_IF -p tcp --dport 22 -j ACCEPT
References
computers/firewall_configuration.1314715939.txt.gz · Last modified: 2011/08/30 22:52 by chkuo