Global Variables

If a global variable exist in an iRule and it is not applied to a Virtual Server, does it still have any affect on the F5 or the traffic. no but you know if irule refers to the global variable, you will get no such variable error and connection will be reseted.

[root@ve10:Active] config  b virtual bar list
virtual bar {
   snat automap
   pool foo
   destination 172.28.19.79:80
   ip protocol 6
   rules myrule
   profiles {
      http {}
      tcp {}
   }
}
[root@ve10:Active] config  b rule myrule list
rule myrule {
   when HTTP_REQUEST {
        log local0. "\$::test $::test"
}
}
[root@ve10:Active] config  b rule myglobal list
rule myglobal {
   when HTTP_REQUEST {
        set ::test "hello world"
}
}

[root@ve10:Active] config  curl -I http://172.28.19.79
curl: (52) Empty reply from server

[root@ve10:Active] config  cat /var/log/ltm
Aug 25 18:57:33 local/tmm err tmm[4925]: 01220001:3: TCL error: myrule  - can't read "::test": no such variable     while executing "log local0. "\$::test $::test""

If a global variable exists in an iRule, does that variable only affect the Virtual Server it is applied to?no. it is visible globally.

Since this iRule exist and is applied to a Virtual Server, does that mean it would affect requests to a separate virtual host that doesn't have that iRule applied?no. global variable is just a variable which is globally accessible. traffic will be load-balanced based on virtual server configuration which handles that traffic.

hope this helps.