Caching DNS forwarder on LTM

Hi,

 

I try to enable caching DNS forwarder feature on my LTM cluster. My BIG-IP version is 11.4.0, I configure according to http://support.f5.com/kb/en-us/products/big-ip_ltm/manuals/product/bigip-dns-cache-implementations-11-2-0/2.html:

 

• DNS cache
• DNS profile
• pool of DNS resolvers
• virtual server

Do not use "GTM listener" because of missing license, and "DNS monitor" because I use standard UDP check.

 

Everyhing looks good, the clients can resolv their DNS queries from this construction, but I see nothing in my local DNS cache, and I see that for every client request BIG-IP resend request to DNS servers without looking up in cache.

 

Please any ideas, what I could check, where I could look for faults?

 

Thank you, Alexej.