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Marcus_Hong_Yu's avatar
Marcus_Hong_Yu
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Jun 13, 2017

RESOLV::lookup not able to pick resolved IP from DNS query answer

I recently used an irule on LTM to do DNS query for traffic forwarding. I used RESOLV::lookup in the irule to go against my DNS server and use resolved IP as pool member IP to establish the connectio...
application delivery
iRules
LTM
Marcus_Hong_Yu's avatar
Marcus_Hong_Yu
Icon for Nimbostratus rankNimbostratus
Jun 13, 2017

hi Cjunior,

 

that's correct. the DNS query irule worked on most of the LTMs in my environment, however this specific pair got issue. This pair only have RD 0. hence I didn't append domain ID in the irule. also, I did a tcpdump when the irule was triggered, I can see the LTM was using it's local selfIP to reach the DNS server and received the correct answer with IP address resolved. however, the resolve::lookup keeps returning as empty. really confused me.