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what happend if you close the port 25?
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I have linux box, in that having 4 interfaces ,each interface is using a different ISP Links...<br />
now i seperated whole network in our lab as three netwoks as 32 its going via &quot;A&quot; ISP and 64 network needs to go via &quot;B&quot; network and 96 network goes via &quot;C&quot; network..<br />
According through this network routing table is also working.. and default &nbsp;0.0.0.0 is going via &quot;eth0&quot;<br />
ie., &nbsp;32 network...if i want to change any network as default network i can change through the command..<br />
Now my question is:<br />
if any thing coming via through the interface &quot;C&quot; from the outside through port no &quot;25&quot; ,i need to send reply also in the same interface (&quot;C&quot;).. for this what lines i need to add in the iptables.. or is there any alternative solution for this.. if have any code please forward me ...<br />
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==Expertblr.
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I have linux box, in that having 4 interfaces ,each interface is using a different ISP Links...
now i seperated whole network in our lab as three netwoks as 32 its going via "A" ISP and 64 network needs to go via "B" network and 96 network goes via "C" network..
According through this network routing table is also working.. and default  0.0.0.0 is going via "eth0"
ie.,  32 network...if i want to change any network as default network i can change through the command..
Now my question is:
if any thing coming via through the interface "C" from the outside through port no "25" ,i need to send reply also in the same interface ("C").. for this what lines i need to add in the iptables.. or is there any alternative solution for this.. if have any code please forward me ...

==Expertblr.

Traffic goes viceversa on  the same interface..

The variety of Linux distributions creates myriad issues relating to configuration and operations when computers are networked, not the least of which is the use of various network management applications, some of which are included with specific distributions, while others are standalone applications.