Forum Discussion
NimbostratusSeeing traffic when vip/ node are down, and have tcpdump's that validate that traffic is still passing.
Hello,
I have a very odd situation. I have a node configured to only respond on TCP port 8081 to incoming http traffic, with a very simple health monitor Get /health_check.txt \r\n. That seems to be working fine. However,
I disabled the VIP and the node and they show down in the network map. Running tcpdump on the F5 (11.4.1) I still see traffic being generated and the http page shows just fine. (and that is after clearing browser cache) In addition, I can telnet to the node on tcp port 8081 and get a response.
I guess my question is this, is the F5 caching the traffic when the VIP, server pool and node are in a disabled state? Has anyone seen this behavior before?
It has be scratching my head.
et
2 Replies
What_Lies_Bene1Cirrostratus
This all relates to the Action on Service Down setting for the Pool. With the default setting existing connections will continue to use a Pool Member even if marked down as long the member continues to service those existing connections.
If you select one of the other options then you won't see this behaviour (they are all fairly obvious).
eroach5Yes, thank you. But the VIP was down hard, but what I did find out was that after the VIP and node were taken out of service the communication continued but only between the F5 and a proxy (which caches content) Looking at another LB instance, where the site page changes content frequently, areas on the page would start to error out, kind of like breaking the content area's that changed.
Thank you for your help.
et
