Difference between revisions of "IP Forwarding and iptables configuration"

From MyWiki
Jump to: navigation, search
Line 20: Line 20:
  
 
iptables -t nat -A POSTROUTING -j MASQUERADE <br>
 
iptables -t nat -A POSTROUTING -j MASQUERADE <br>
 +
 +
'''To delete an entry from the nat table''' <br>
 +
>
 +
iptables -t nat -L -n --line-numbers<br
 +
 +
and find the line that matches the rules you want to deletes.<br>
 +
then
 +
 +
iptables -t nat -D <br>

Revision as of 20:59, 19 February 2016

Forwarding must be enabled
root@raspbx:~# cat /proc/sys/net/ipv4/ip_forward
0
root@raspbx:~# sysctl -w net.ipv4.ip_forward=1
net.ipv4.ip_forward = 1
root@raspbx:~# cat /proc/sys/net/ipv4/ip_forward
1
root@raspbx:~#
Routing and Masquerading
iptables --table nat --append POSTROUTING -o ppp0 -j MASQUERADE
iptables --append FORWARD -i eth0 -j ACCEPT

Forwarding traffic from one port to another machine and port

iptables -t nat -A PREROUTING -p tcp --dport 1111 -j DNAT --to-destination 2.2.2.2:1111

and finally, we ask IPtables to masquerade:

iptables -t nat -A POSTROUTING -j MASQUERADE

To delete an entry from the nat table
> iptables -t nat -L -n --line-numbers<br

and find the line that matches the rules you want to deletes.
then

iptables -t nat -D