WARNING: recursion requested but not available, 3 servers only one fails

Question

• Primary nameserver at pp.pp.pp.pp
• Secondary namseserver ss.ss.ss.ss
• third namserver at tt.tt.tt.tt

primary named.conf
acl "trusted" {
  ss.ss.ss.ss;
  tt.tt.tt.tt;
  localhost;
};

from third

dig @pp.pp.pp.pp www.google.com

I get answers.

But from the secondary:

dig @pp.pp.pp.pp www.google.com

I get WARNING: recursion requested but not available and no answer.

If I comment out the third server in the primary's named.conf trusted section, and rndc reload, I get the WARNING: recursion requested but not available. Uncomment, rndc reload, re-dig, warning it goes away.

The primary sees the secondary as external apparently and is not obeying the trusted setting.

Appreciate any suggestions to fix.

Solution

I found the problem, which leads to a different question.

The secondary server is sending it's query from it's secondary IP address. It has a secondary on the same interface (eth0:1).

I added that to the trusted lists and it cured the DNS lookup.

But why is it querying from the secondary IP instead of the primary?