Load Balance Friendly URL to two unfriendly URL's

e.g.

 configuration

[root@ve11c:Active:In Sync] config  tmsh list ltm virtual bar
ltm virtual bar {
    destination 172.28.24.10:80
    ip-protocol tcp
    mask 255.255.255.255
    pool foo
    profiles {
        http { }
        tcp { }
    }
    rules {
        qux
    }
    source 0.0.0.0/0
    source-address-translation {
        type automap
    }
    vs-index 12
}
[root@ve11c:Active:In Sync] config  tmsh list ltm pool foo
ltm pool foo {
    members {
        200.200.200.101:80 {
            address 200.200.200.101
        }
        200.200.200.111:80 {
            address 200.200.200.111
        }
    }
}
[root@ve11c:Active:In Sync] config  tmsh list ltm data-group internal node2name
ltm data-group internal node2name {
    records {
        200.200.200.101 {
            data myunfriendlyurl1.com
        }
        200.200.200.111 {
            data myunfriendlyurl2.com
        }
    }
    type string
}
[root@ve11c:Active:In Sync] config  tmsh list ltm rule qux
ltm rule qux {
    when HTTP_REQUEST_SEND {
  if { [class match -- [LB::server addr] equals node2name] } {
    clientside {
      HTTP::header replace Host [class match -value [LB::server addr] equals node2name]
    }
  }
}
}

 1st trace

[root@ve11c:Active:In Sync] config  ssldump -Aed -nni 0.0 port 80
New TCP connection 1: 172.28.24.1(52504) <-> 172.28.24.10(80)
1426159661.7394 (0.0008)  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
Accept: */*
Host: myfriendlyurl.com

---------------------------------------------------------------

New TCP connection 2: 200.200.200.14(52504) <-> 200.200.200.111(80)
1426159661.7433 (0.0037)  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
Accept: */*
Host: myunfriendlyurl2.com

---------------------------------------------------------------

 2nd trace

[root@ve11c:Active:In Sync] config  ssldump -Aed -nni 0.0 port 80
New TCP connection 1: 172.28.24.1(52506) <-> 172.28.24.10(80)
1426159691.3216 (0.0017)  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
Accept: */*
Host: myfriendlyurl.com

---------------------------------------------------------------

New TCP connection 2: 200.200.200.14(52506) <-> 200.200.200.101(80)
1426159691.3496 (0.0279)  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
Accept: */*
Host: myunfriendlyurl1.com

---------------------------------------------------------------

please be noted that this irule does rewrite host header in request only. it does nothing on response.