Inter-VLAN Routing on F5

Setting up the F5 as a router is fairly simple (once you know how to do that 😉

According to some technotes all you basically needs to do is:

 
ltm virtual /Common/VS_ROUTE {
    destination /Common/0.0.0.0:any
    ip-forward
    mask any
    profiles {
        /Common/FASTL4_ROUTE { }
    }
    translate-address disabled
    translate-port disabled
    vlans-disabled
}
ltm virtual-address /Common/0.0.0.0 {
    address any
    arp disabled
    mask any
    traffic-group /Common/traffic-group-1
}
ltm profile fastl4 /Common/FASTL4_ROUTE {
    app-service none
    defaults-from /Common/fastL4
    loose-close enabled
    loose-initialization enabled
    reset-on-timeout disabled
}

*se below for udp config*

and voila the F5 will start to behave like a router/L3-switch (looking at its routing table for traffic that doesnt match any other VS). If you need dynamic routing you enable zebos in the ssh and then use vtysh to get cisco-style configuration (unfortunately the dynamic routing config isnt available in the GUI - only in the cli/ssh).

A note regarding the idle timout, its just to clear the flow from the internal statetable (since reset on timeout is disabled) in order to keep the statetable as short (and fast) as possible. One could see the statetable in this case as similar to CEF (Cisco Express Forwarding) if you are used to cisco-lingo.