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NimbostratusAbnormal hang to connect F5 VIP
Currently, I setup F5 LTM version 11.4.x to balance the web loading from Proxy server. All traffic will go through from proxy server to F5 VIP and round robin to pass for web server layers. The VIP in F5 is different VLANs with the below web servers. E.g VIP is 10.112.42.x, and the web servers are 10.113.99.xxx. After I set up and enable SNAT automap function. I tried to run curl and telnet command to connect the VIP port 80 from proxy server. It is working, but if no continuous traffic connect from proxy server to this VIP within around 10 min, it happen abnormal situation. If we idle over around 10 min , and try to run command to telnet VIP port 80 again, it likes hang connection and return timeout. I checked the health checking, all pools web server memebers are normal. For this case, if I modify little in configuration ( E.g update some description ) in F5, it can work again. But if no traffic connect VIP over 10min again, the issue happened again. I tried to disable health checking, but it also keeps to happen it. Do you have any idea why will happen it ? Please give us some idea to find out the issue. Thanks a lot !
Sum
12 Replies
NikhilBEmployee
" it happen abnormal situation." - can you pls elaborate?
kunjanAre you able to curl from command line on the LTM when proxy cannot connect to LTM VS? Same time check if you can ping the VS from the said proxy.
hoksum2828_1750When the proxy cannot connect to VIP, I tried to run same curl and ping command to connect the VIP in LTM. It also does not work. Who can help us to find out the root cause for this issue ? Thanks a lot !
Sum
- kunjan
tried to run same curl and ping command to connect the VIP in LTM.
Where did you try this from? LTM Cli?
- hoksum2828_1750
HI Kunjan
Thank you for your help. I used ssh to log in LTM and run curl and ping commands from it ! Do you have any good idea about this issue ?
Sum
- kunjan
I checked the health checking, all pools web server memebers are normal.
So even when the VIP is up(green) if you can't ping from LTM, that will be strange. Can you confirm that?
- hoksum2828_1750
Hi Kunjan
I double checked it, the VIP is up and the light is green when we can't ping from LTM.
Sum
- kunjan
For this case, if I modify little in configuration ( E.g update some description ) in F5, it can work again.
Is it configured with route domain? Are you able to ping from LTM during the 10 minutes when it is working?
- hoksum2828_1750
Hi Kunjan
I only changed the description parameter in "Virtual Server List" option. Yes, I can ping from LTM during 10 min when it is working. : (
Sum
- kunjan
Is the arp disabled? The following cmd will show
tmsh list ltm virtual-address VIP_IP all-properties
