IP Routing Features 
Configuring IP Parameters for Routing Switches 
Changing the TTL Threshold 
The configuration of this parameter is covered in chapter 7, “Configuring IP 
Addressing”. 
Enabling Forwarding of Directed Broadcasts 
A directed broadcast is an IP broadcast to all devices within a single directly-
attached network or sub-net. A net-directed broadcast goes to all devices on 
a given network. A sub-net-directed broadcast goes to all devices within a 
given sub-net. 
Note  A less common type, the all-sub-nets broadcast, goes to all directly-attached 
sub-nets. Forwarding for this broadcast type also is supported, but most 
networks use IP multicasting instead of all-sub-net broadcasting. 
Forwarding for all types of IP directed broadcasts is disabled by default. You 
can enable forwarding for all types if needed. You cannot enable forwarding 
for specific broadcast types. 
To enable forwarding of IP directed broadcasts, enter the following CLI 
command: 
HPswitch(config)# ip directed-broadcast 
Syntax:  [no] ip directed-broadcast 
HP software makes the forwarding decision based on the routing switch's 
knowledge of the destination network prefix. Routers cannot determine that 
a message is unicast or directed broadcast apart from the destination network 
prefix. The decision to forward or not forward the message is by definition 
only possible in the last hop router. 
To disable the directed broadcasts, enter the following CLI command: 
HPswitch(config)# no ip directed-broadcast 
11-14