Irule Creation

[root@iris:Active] config  b virtual bar list
virtual bar {
   snat automap
   pool foo
   destination 172.28.17.33:http
   ip protocol tcp
   rules myrule
   profiles {
      http {}
      tcp {}
   }
}
[root@iris:Active] config  b rule myrule list
rule myrule {
   when HTTP_REQUEST {
        if {not ([string tolower [HTTP::host]] starts_with "www")} {
                HTTP::header replace Host "www.[HTTP::host]"
        }
}
}

---------------------------------------------------------------
New TCP connection 1: 172.28.16.50(44422) <-> 172.28.17.33(80)
1319032099.4764 (0.0013)  C>S
---------------------------------------------------------------
HEAD / HTTP/1.1
User-Agent: curl/7.15.5 (i686-redhat-linux-gnu) libcurl/7.15.5 OpenSSL/0.9.8b zlib/1.2.3 libidn/0.6.5
Host: abc.com
Accept: */*

---------------------------------------------------------------
New TCP connection 2: 10.10.72.30(44422) <-> 10.10.70.110(80)
1319032099.4769 (0.0003)  C>S
---------------------------------------------------------------
HEAD / HTTP/1.1
User-Agent: curl/7.15.5 (i686-redhat-linux-gnu) libcurl/7.15.5 OpenSSL/0.9.8b zlib/1.2.3 libidn/0.6.5
Host: www.abc.com
Accept: */*

[root@iris:Active] config  b virtual bar list
virtual bar {
   snat automap
   pool foo
   destination 172.28.17.33:http
   ip protocol tcp
   rules myrule
   profiles {
      http {}
      tcp {}
   }
}
[root@iris:Active] config  b rule myrule list
rule myrule {
   when HTTP_REQUEST {
        if {not ([string tolower [HTTP::host]] starts_with "www")} {
                virtual barbar
        }
}
}
[root@iris:Active] config  b virtual barbar list
virtual barbar {
   snat automap
   pool foo
   destination 172.28.17.44:http
   ip protocol tcp
}

---------------------------------------------------------------
New TCP connection 1: 172.28.16.50(34836) <-> 172.28.17.33(80)
1319032322.1664 (0.0005)  C>S
---------------------------------------------------------------
HEAD / HTTP/1.1
User-Agent: curl/7.15.5 (i686-redhat-linux-gnu) libcurl/7.15.5 OpenSSL/0.9.8b zlib/1.2.3 libidn/0.6.5
Host: abc.com
Accept: */*

---------------------------------------------------------------
New TCP connection 2: 172.28.16.50(34836) <-> 172.28.17.44(80)
1319032322.1665 (0.0000)  C>S
---------------------------------------------------------------
HEAD / HTTP/1.1
User-Agent: curl/7.15.5 (i686-redhat-linux-gnu) libcurl/7.15.5 OpenSSL/0.9.8b zlib/1.2.3 libidn/0.6.5
Host: abc.com
Accept: */*

---------------------------------------------------------------
New TCP connection 3: 10.10.72.30(34836) <-> 10.10.70.110(80)
1319032322.1704 (0.0038)  C>S
---------------------------------------------------------------
HEAD / HTTP/1.1
User-Agent: curl/7.15.5 (i686-redhat-linux-gnu) libcurl/7.15.5 OpenSSL/0.9.8b zlib/1.2.3 libidn/0.6.5
Host: abc.com
Accept: */*