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Forum Discussion

adithyodw_18563's avatar
adithyodw_18563
Icon for Nimbostratus rankNimbostratus
Aug 31, 2015

F5 Pool Members flapping issue

Dear All,   We are facing issue with monitoring of nodes in one of our virtual server pool, however when we check on the server side we didn’t found any discrepancy on server port side. Due to thi...
application delivery
availability
LTM
Brad_Parker's avatar
Brad_Parker
Icon for Cirrus rankCirrus
Sep 01, 2015

Change your tcpdump to 

tcpdump -i 1.15 -ni vlan_internal host 10.64.32.16 and host 10.64.32.35
so you can see the response or lack there of coming back from your pool members. If they don't respond within 16 seconds they will be marked down based on the timeout of 16 seconds in your default tcp monitor. Also, have you enabled monitor logging for one of your flapping pool members to see why its being marked down? Once you do that each pool member that has that enabled will have a log at /var/log/monitors/.

Brad_Parker's avatar
Brad_Parker
Icon for Cirrus rankCirrus
Sep 01, 2015
Also, what version of Big-IP are you on? Could you be suffering from this bug, https://support.f5.com/kb/en-us/solutions/public/15000/900/sol15907.html?