Using Client Subnet in DNS Requests

BIG-IP DNS 14.0 now supports edns-client-subnet (ECS) for both responding to client requests (GSLB) or forwarding client requests (screening). The following is a quick start on using this feature. ...
Published Sep 14, 2018
Version 1.0
application delivery
BIG-IP DNS
arya_wae24's avatar
arya_wae24
Icon for Nimbostratus rankNimbostratus
Apr 09, 2026

Hi,
We've implement 2-tier DNS using F5.
The topology is Client --> DNS_Cache (F5) --> DNS_resolver (F5) --> Internet.
We enable SNAT at DNS_cache.

how to insert  client subnet record at DNS_cache? because we get error "01071d16:3: DNS profile (/Common/dns64) cannot have both edns0 client subnet insertion and the DNS cache enabled simultaneously." when try to enable "Insert Source Address into Client Subnet Option " at DNS profile.

Any solution except using the irules?

when DNS_REQUEST {
    DNS::edns0 subnet address [IP::client_addr]
    DNS::edns0 subnet source 32
}