Forum Discussion

Franky-frank-reg7's avatar
Franky-frank-reg7
Icon for Altocumulus rankAltocumulus
Sep 24, 2023

F5 SMTP Fast Template - SNAT Not working as expected

Hello all, I'm having issues with getting SMTP to work with the FAST templates. Specifically, I'm trying to configure an SMTP template with no SNAT option checked so the backend pool members receive...
application delivery
  • Paulius's avatar
    Paulius
    Oct 06, 2023

    Franky-frank-reg7 That is true but to simplify the configuration so that you reduce the man hours you might/will spend in the future troubleshoot a non-standard deployment of the F5 you should deploy it as option 1

Franky-frank-reg7's avatar
Franky-frank-reg7
Icon for Altocumulus rankAltocumulus
Sep 25, 2023

The traffic is definitely making it through the VIP, we configured the template with the domain name "mycompanytest.com",  and it's exaclty what appears in the output of the SMTP logs on the server.

  • Paulius's avatar
    Paulius
    Icon for MVP rankMVP
    Sep 25, 2023

    Franky-frank-reg7 What does the virtual server and any associated configuration look like? Do you see SNAT enabled on the virtual server?

    • Franky-frank-reg7's avatar
      Franky-frank-reg7
      Icon for Altocumulus rankAltocumulus
      Sep 25, 2023

      It's a very straight forward configuration. There is no SNAT configured, no SSL profiles (Client/Server), or VLAN filters. Please see the snip below:

       

      We just re-tested and it appears it may have been correct, the traffic we saw on the servers were the healthy monitors. The thing I can't describe is why traffic isn't making through the VS, exchange and other applications we deployed with FAST templates are working. Just not SMTP at the moment.

      • Paulius's avatar
        Paulius
        Icon for MVP rankMVP
        Sep 25, 2023

        Franky-frank-reg7 I recommend using tcpdump to see if you can catch anything as it comes in.

        tcpdump -nni 0.0:nnp host 10.10.200.200 and port 25 -w /shared/tmp/smtp_tshoot.pcap

        With this you should be able to see if traffic is making it to the F5 and if it's being handled by an incorrect virtual server it would show that information as an additional tag labeled F5 I believe.