Mar 27, 2026 - For details about updated CVE-2025-53521 (BIG-IP APM vulnerability), refer to K000156741.

Forum Discussion

isspwk_39034's avatar
isspwk_39034
Icon for Nimbostratus rankNimbostratus
Aug 12, 2009

http_request and lb-selected event

I was experimenting F5 LTM using http_request and lb_selected events.   I noticed that lb_selected event may not occur for each http_request event.   Can you clarify what lb_selected event d...
application delivery
dev
devops
irules
isspwk_39034's avatar
isspwk_39034
Icon for Nimbostratus rankNimbostratus
Aug 12, 2009
Hi Aaron,

 

Thanks for helping.

 

I was verifying on the default cookie persistence profile of my virtual server.

 

I have a virtual server with 2 members in the pool.

 

I attached a irule with the virtual server.

 

My irule is as follows:

 

 

when HTTP_REQUEST {

 

if { [HTTP::cookie exists "USER_ID"] } then {

 

if { [HTTP::cookie exists "BIGipServerMy_Pool"] } then {

 

log local0. "[IP::client_addr] \t Not Yet Available \t [HTTP::cookie "USER_ID"] \t [HTTP::cookie "BIGipServerMy_Pool"] \t [HTTP::uri]"

 

} else {

 

log local0. "[IP::client_addr] \t Not Yet Available \t [HTTP::cookie "USER_ID"] \t\t [HTTP::uri]"

 

}

 

} else {

 

log local0. "[IP::client_addr] \t Not Yet Available \t\t\t [HTTP::uri]"

 

}

 

}

 

when LB_SELECTED {

 

if { [HTTP::cookie exists "USER_ID"] } then {

 

if { [HTTP::cookie exists "BIGipServerMy_Pool"] } then {

 

log local0. "[IP::client_addr] \t [LB::server addr] \t [HTTP::cookie "USER_ID"] \t [HTTP::cookie "BIGipServerMy_Pool"] \t [HTTP::uri]"

 

} else {

 

log local0. "[IP::client_addr] \t [LB::server addr] \t [HTTP::cookie "USER_ID"] \t\t [HTTP::uri]"

 

}

 

} else {

 

log local0. "[IP::client_addr] \t [LB::server addr] \t\t\t [HTTP::uri]"

 

}

 

}

 

when LB_FAILED {

 

if { [HTTP::cookie exists "USER_ID"] } then {

 

if { [HTTP::cookie exists "BIGipServerMy_Pool"] } then {

 

log local0. "[IP::client_addr] \t [LB::server addr] \t [HTTP::cookie "USER_ID"] \t [HTTP::cookie "BIGipServerMy_Pool"] \t [HTTP::uri]"

 

} else {

 

log local0. "[IP::client_addr] \t [LB::server addr] \t [HTTP::cookie "USER_ID"] \t\t [HTTP::uri]"

 

}

 

} else {

 

log local0. "[IP::client_addr] \t [LB::server addr] \t\t\t [HTTP::uri]"

 

 

----

 

And my log is as follows:

 

 

Aug 12 20:08:24 tmm tmm[1807]: Rule TestRule : 10.10.13.13 Not Yet Available /cfm/index.cfm

 

Aug 12 20:08:24 tmm tmm[1807]: Rule TestRule : 10.10.13.13 137.132.xxx.xxx /cfm/index.cfm

 

Aug 12 20:08:24 tmm tmm[1807]: Rule TestRule : 10.10.13.13 Not Yet Available /cfm/login.cfm?user_id=test0001&password=password

 

Aug 12 20:08:24 tmm tmm[1807]: Rule TestRule : 10.10.13.13 137.132.xxx.xxx /cfm/login.cfm?user_id=test0001&password=password

 

Aug 12 20:08:25 tmm tmm[1807]: Rule TestRule : 10.10.13.13 Not Yet Available /cfm/index.cfm

 

Aug 12 20:08:25 tmm tmm[1807]: Rule TestRule : 10.10.13.13 137.132.xxx.yyy /cfm/index.cfm

 

Aug 12 20:08:25 tmm tmm[1807]: Rule TestRule : 10.10.13.13 Not Yet Available /cfm/login.cfm?user_id=test0002&password=password

 

Aug 12 20:08:25 tmm tmm[1807]: Rule TestRule : 10.10.13.13 137.132.xxx.yyy /cfm/login.cfm?user_id=test0002&password=password

 

Aug 12 20:08:26 tmm tmm[1807]: Rule TestRule : 10.10.13.13 Not Yet Available /cfm/index.cfm

 

Aug 12 20:08:26 tmm tmm[1807]: Rule TestRule : 10.10.13.13 137.132.xxx.xxx /cfm/index.cfm

 

Aug 12 20:08:26 tmm tmm[1807]: Rule TestRule : 10.10.13.13 Not Yet Available /cfm/login.cfm?user_id=test0003&password=password

 

Aug 12 20:08:26 tmm tmm[1807]: Rule TestRule : 10.10.13.13 137.132.xxx.xxx /cfm/login.cfm?user_id=test0003&password=password

 

Aug 12 20:08:27 tmm tmm[1807]: Rule TestRule : 10.10.13.13 Not Yet Available /cfm/index.cfm

 

Aug 12 20:08:27 tmm tmm[1807]: Rule TestRule : 10.10.13.13 137.132.xxx.yyy /cfm/index.cfm

 

Aug 12 20:08:27 tmm tmm[1807]: Rule TestRule : 10.10.13.13 Not Yet Available /cfm/login.cfm?user_id=test0004&password=password

 

Aug 12 20:08:27 tmm tmm[1807]: Rule TestRule : 10.10.13.13 137.132.xxx.yyy /cfm/login.cfm?user_id=test0004&password=password

 

Aug 12 20:08:28 tmm tmm[1807]: Rule TestRule : 10.10.13.13 Not Yet Available /cfm/index.cfm

 

Aug 12 20:08:28 tmm tmm[1807]: Rule TestRule : 10.10.13.13 137.132.xxx.xxx /cfm/index.cfm

 

Aug 12 20:08:28 tmm tmm[1807]: Rule TestRule : 10.10.13.13 Not Yet Available /cfm/login.cfm?user_id=test0005&password=password

 

Aug 12 20:08:28 tmm tmm[1807]: Rule TestRule : 10.10.13.13 137.132.xxx.xxx /cfm/login.cfm?user_id=test0005&password=password

 

Aug 12 20:08:29 tmm tmm[1807]: Rule TestRule : 10.10.13.13 Not Yet Available test0001 xxxxxxxxxxxx.20480.0000 /1.htm

 

Aug 12 20:08:29 tmm tmm[1807]: Rule TestRule : 10.10.13.13 137.132.xxx.xxx test0001 xxxxxxxxxxxx.20480.0000 /1.htm

 

Aug 12 20:08:30 tmm tmm[1807]: Rule TestRule : 10.10.13.13 Not Yet Available test0002 yyyyyyyyyyyy.20480.0000 /2.htm

 

Aug 12 20:08:30 tmm tmm[1807]: Rule TestRule : 10.10.13.13 Not Yet Available test0002 yyyyyyyyyyyy.20480.0000 /login_popup.cfm?path=/2.htm

 

Aug 12 20:08:31 tmm tmm[1807]: Rule TestRule : 10.10.13.13 Not Yet Available test0003 xxxxxxxxxxxx.20480.0000 /3.htm

 

Aug 12 20:08:31 tmm tmm[1807]: Rule TestRule : 10.10.13.13 137.132.xxx.xxx test0003 xxxxxxxxxxxx.20480.0000 /3.htm

 

Aug 12 20:08:32 tmm tmm[1807]: Rule TestRule : 10.10.13.13 Not Yet Available test0004 yyyyyyyyyyyy.20480.0000 /4.htm

 

Aug 12 20:08:32 tmm tmm[1807]: Rule TestRule : 10.10.13.13 Not Yet Available test0004 yyyyyyyyyyyy.20480.0000 /login_popup.cfm?path=/4.htm

 

Aug 12 20:08:33 tmm tmm[1807]: Rule TestRule : 10.10.13.13 Not Yet Available test0005 xxxxxxxxxxxx.20480.0000 /5.htm

 

Aug 12 20:08:33 tmm tmm[1807]: Rule TestRule : 10.10.13.13 137.132.xxx.xxx test0005 xxxxxxxxxxxx.20480.0000 /5.htm

 

Aug 12 20:08:34 tmm tmm[1807]: Rule TestRule : 10.10.13.13 Not Yet Available test0001 xxxxxxxxxxxx.20480.0000 /6.htm

 

Aug 12 20:08:35 tmm tmm[1807]: Rule TestRule : 10.10.13.13 Not Yet Available test0002 yyyyyyyyyyyy.20480.0000 /7.htm

 

Aug 12 20:08:35 tmm tmm[1807]: Rule TestRule : 10.10.13.13 Not Yet Available test0002 yyyyyyyyyyyy.20480.0000 /login_popup.cfm?path=/7.htm

 

Aug 12 20:08:36 tmm tmm[1807]: Rule TestRule : 10.10.13.13 Not Yet Available test0003 xxxxxxxxxxxx.20480.0000 /8.htm

 

Aug 12 20:08:36 tmm tmm[1807]: Rule TestRule : 10.10.13.13 137.132.xxx.xxx test0003 xxxxxxxxxxxx.20480.0000 /8.htm

 

Aug 12 20:08:37 tmm tmm[1807]: Rule TestRule : 10.10.13.13 Not Yet Available test0004 yyyyyyyyyyyy.20480.0000 /9.htm

 

Aug 12 20:08:37 tmm tmm[1807]: Rule TestRule : 10.10.13.13 Not Yet Available test0004 yyyyyyyyyyyy.20480.0000 /login_popup.cfm?path=/9.htm

 

 

Does it mean that when LB is selected in the first request, the next request by the same client will not require LB_SELECTED event?

 

Thanks.

 

 

wk