Mar 27, 2026 - For details about updated CVE-2025-53521 (BIG-IP APM vulnerability), refer to K000156741.

Forum Discussion

nkroon1's avatar
nkroon1
Icon for Cirrus rankCirrus
Jun 08, 2021

GLB Return Nothing on Down

Hello! I have a GLB entry that has 1 pool and the pool has 2 members. Currently, if both pool members are down, it returns both answers. I'm looking to have it return nothing when down. Is this a fea...
application delivery
big-ip
BIG-IP DNS
Nikoolayy1's avatar
Nikoolayy1
Icon for MVP rankMVP
Jun 09, 2021

1.It seems to me that you are matching the "Return to DNS" load balancing default fallback method.

 

 

https://support.f5.com/csp/article/K28650431

 

 

2.You can see the available methods here and you may test "Drop Packet":

 

 

https://techdocs.f5.com/kb/en-us/products/big-ip-dns/manuals/product/bigip-dns-load-balancing-13-1-0/1.html

 

 

3.You may also leave "Return to DNS" unde the Wide IP and attach a modified DNS profile under your listener with "Unhandled Query Actions" set to Reject or other action you like (read about this) and with Use BIND Server on BIG-IP disabled just in case even if it shouldn't be needed to be dissable.

 

 

https://support.f5.com/csp/article/K21520582

  • Nikoolayy1's avatar
    Nikoolayy1
    Icon for MVP rankMVP
    Jun 28, 2021

    Hello,

     

     

    Have you solved your issue? Also if needed enable wide-ip logging to see how the wider ip handles the DNS request and if the "Return to DNS" load balancing method is triggered.

     

     

    https://support.f5.com/csp/article/K25751652