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In general, such a problem, there is a system RHEL 6.4 Server with a pair of network interfaces combined into one by bonding. This system IP address: 10.7.7.1. Next on the system running an application that needs to connect to the MySQL-server 10.7.7.2 on port 3306 . And in fact, MySQL runs on 10.7.7.3. Connection settings in the application are hardcoded therefore can not be changed . That can be heard through iptables do address translation . How to make so that when the application attempted to 10.7.7.2:3306 iptables is intercepted and sent a request to 10.7.7.3:3306, and got a response back, and feed it to the application?

abg
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2 Answers2

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This can be done with NAT rules in iptables.

If the MySQL server is on the same host, use a REDIRECT rules. Redirect all connections to port 3306 not to 10.7.7.3 to the required address.

If the MySQL server is not on the same host the, use a DNAT rule.

BillThor
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Assuming that

  • .1, .2, and .3 are different machines
  • You can't swap .2 & .3's IP Addresses
  • .2 is running Linux

Here's what you need to add on .2:

-t nat -A PREROUTING  -d 10.7.7.2 -p tcp --dport 3306 -j DNAT --to-destination 10.7.7.3
-t nat -A POSTROUTING -d 10.7.7.3 -p tcp --dport 3306 -j SNAT --to-source      10.7.7.2

HOWEVER...

If for some reasons you can't create iptables rules on .2 and/or you want to intercept the traffic on .1, all you need to do on .1 is:

-t nat -A POSTROUTING -d 10.7.7.2 -p tcp --dport 3306 -j DNAT --to-destination 10.7.7.3
pepoluan
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