F5 DNS handles all DNS Request from internal to Google DNS

Hello everyone, Hope you have a nice day.

• Currently i have F5 LTM facing to internet:

  Server ----- Firewall ----- F5 LTM --WAN /30----ISP-- Internet

  F5 will perform SNAT traffic internet from Server to Internet

• I planed to change to new F5 device Server ------ Firewall ----- F5 LTM & DNS (1 physical device) --WAN /30----ISP-- Internet i configured wide IP, Zonerunner and ( i don't configured Listener)

• when i've done the change to use new F5. All DNS Qeury from Server to 8.8.8.8 is fail Server -> Send Qeury DNS to Googole 8.8.8.8 -------- Firewall (Allow) ------- F5 perform SNAT to internet ---- internet

The strange thing happen with NAT Table on F5

   Tradition IP ------------------------------------------------- NAT IP

Src IP: ServerIP -- DesIP: 8.8.8.8:53 SrcIP:PublicIP (IP on F5) DestIP: PublicIP (IP on F5)

I dont know why F5 perform DNAT.

Thanks & Best Regards.