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Hi All,<br>
<br>
We know that when binding the real server to a virtual, a layer 4 or
layer 7 health check enabled atomically.<br>
for well known ports will use layer 7 health check by default, for
non well known ports will use layer 4 by default.<br>
<br>
But I found that the Server port 995 UP and DOWN showing on syslog.
<br>
<font color="#000099"><span class="535321402-15062011"><font
face="PMingLiU">Mar 31 16:47:13:N:L4 server 10.198.101.8
HKISAS03 port 995 is up <br>
Mar 31 16:47:11:N:L4 server 10.198.101.8 HKISAS03 port 995 is
down due to healthcheck <br>
Mar 31 16:39:03:N:L4 server 10.198.101.8 HKISAS03 port 995 is
up <br>
Mar 31 16:39:01:N:L4 server 10.198.101.8 HKISAS03 port 995 is
down due to healthcheck <br>
Mar 30 23:22:33:N:L4 server 10.198.101.8 HKISAS03 port 995 is
up <br>
Mar 30 23:22:31:N:L4 server 10.198.101.8 HKISAS03 port 995 is
down due to healthcheck <br>
Mar 30 22:44:28:N:L4 server 10.198.101.8 HKISAS03 port 995 is
up </font></span></font><br>
It look like HC flapping (passed layer 4 but failed layer 7 checks).
Suppose either L4 or L7 only. <br>
<br>
I did some troubleshooting as below;<br>
1. I can see there are only L4 checks in packet capture. <br>
2. The UP and DOWN issue can be fixed by increase the keepalive
interval from 10 to 60.<br>
<br>
I am very confuse that the UP and DOWN issue is really came from
flapping? why the packet capture cannot see the layer 7 HC?<br>
If it is a bug. I think the only way to help is disable the L7 HC
for port 995, right? But how come it can be fixed by enlarge the
keepalive interval?<br>
<br>
Much appreciated if anyone can advice. Thanks!<br>
<br>
Rgds,<br>
LI <br>
<br>
<br>
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