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Forum Discussion

Mayur_Jadhav's avatar
Mayur_Jadhav
Icon for Cirrus rankCirrus
May 19, 2020

F5 Monitor tcp_half_open is getting down error Ipv4 address mismatch

Hi Team,   I could see our pool monitor tcp_half_open is becoming down due to IPv4 address mismatch error? what is this error? This issue is intermittent. After some time members are coming up....
application delivery
BIG-IP
LTM
Shaun_Simmons's avatar
Shaun_Simmons
Icon for Employee rankEmployee
May 19, 2020

This KB may help: https://support.f5.com/csp/article/K12829

-It is an older KB that is no longer maintained.

 

--I hope this helps! Have a great day!

 

Workaround

To work around this issue, you can remove the TCP half open monitor from the pool or node and then add the monitor back. To do so, perform the following procedure:

Note: This workaround may need to be performed following each system reboot.

  1. Log in to the Configuration utility.
  2. Navigate to Local Traffic > Pools or Nodes.
  3. Click the appropriate pool or node object.
  4. Remove the TCP half open monitor.
  5. Click Update.
  6. Re-add the monitor to the pool or node object.
  7. Click Update.

 

Mayur_Jadhav's avatar
Mayur_Jadhav
Icon for Cirrus rankCirrus
May 19, 2020

I am currently working on 12.1.5, Also monitors are already up. No need to perform workaround.

 

What is the reason of this issue