Forum Discussion
Cory_50405
May 08, 2014Noctilucent
No. The DNS query to GTM will be completely independent to the subsequent data connection by the client over SMTP.
- kingmuir_152188May 08, 2014NimbostratusSo do i need to use LTM?
- Cory_50405May 08, 2014NoctilucentThere was another thread about this same issue yesterday: https://devcentral.f5.com/s/feed/0D51T00006j3sF1SAI Unless the SMTP server is configured to route through the LTM to reach the connecting clients, then it won't be able to grab the client IP address due to SNAT on the LTM.
- kingmuir_152188May 08, 2014NimbostratusBit confused, so the only way to get smtp relay load balanced is to set it up on the ltm layer then set Source Address Translation to none and add a route from the relay box back to the ltm? Wanted to try just use the GTM layer?
- Cory_50405May 08, 2014NoctilucentThe GTM isn't actually seeing any of the SMTP traffic. It's only providing MX record resolution to the requesting client. And this request is likely going to come from a local DNS server instead of the SMTP server itself, so GTM wouldn't be of much help as far as logging is concerned.
- kingmuir_152188May 08, 2014Nimbostratus..but it would work?
- Cory_50405May 08, 2014NoctilucentIf you're referring to the GTM providing an MX record response (pointing to the LTM virtual server) to a requesting DNS server, then a client attempting an SMTP data connection to the LTM virtual server, that part will work. If the logging portion at the SMTP server level is what you are referring to, then that portion will only work if the LTM is not performing any SNAT.