source port

OrC82 · 07-08-2009, 06:53 AM

Hi,
I'm using iptables.
i need to create a rule for specific IP, that all traffic to this IP will go from specific source PORT.
it is possible ?
for example:
tcp 0 0 192.168.50.82:22 192.168.50.159:3057 ESTABLISHED

I need that port 3057 will be constant for this ip 192.168.50.159

OrC82 · 07-08-2009, 08:20 AM

please anyone....
any ideas ??

XavierP · 07-08-2009, 08:25 AM

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centosboy · 07-08-2009, 08:26 AM

Quote:

Originally Posted by OrC82

Hi,
I'm using iptables.
i need to create a rule for specific IP, that all traffic to this IP will go from specific source PORT.
it is possible ?
for example:
tcp 0 0 192.168.50.82:22 192.168.50.159:3057 ESTABLISHED

I need that port 3057 will be constant for this ip 192.168.50.159

if i understand the question correctly -

Code:

iptables -I INPUT -p tcp -s 192.168.50.159 --sport 3057 -d 192.168.50.82 --dport 22 -j ACCEPT

gratuitous_arp · 07-08-2009, 01:35 PM

Your explanation is a little hard to follow.

Code:

iptables -t nat -A POSTROUTING -p tcp --source 192.168.50.159/32 -j SNAT --to-source 192.168.50.159:3057

This will take the source IP address and port of 192.168.50.159:any-tcp and change it to 192.168.50.159:3057-tcp for any packet that leaves the machine (as long as it is an exact match of the specified IP address). You would enter this rule on the box that has an IP of 192.168.50.159. You could make another rule for udp.