From Sending Updates - HP 7102dl - ProCurve Secure Router Configuration Manual

IP Routing—Configuring RIP, OSPF, BGP, and PBR
Configuring RIP
15-30
Configuring a Passive Interface: Prohibiting an Interface

from Sending Updates

In some situations, you may want an interface to receive routes but not to
broadcast its own routing table. For example, you can configure a loopback
interface as a passive interface to prevent it from sending out updates through
a physical interface that has already sent out updates of its own. Or, your
network might include a set of high-security subnets that other subnets should
not be able to access. However, the high-security subnets need to access the
rest of the network. The interface on the router that connects the high-security
area to the rest of the network should be a passive interface. It can receive
RIP updates from other routers but will not send its own routing table.
When a WAN router communicates with an external network, you might want
it to receive external routes but not to broadcast routing information about
your private network. Again, you can specify that the WAN interface be a
passive interface.
Enter the following RIP configuration command to configure a passive
interface:
Syntax: passive-interface <interface ID>
For example, you might want the PPP 1 interface to be a passive interface:
ProCurve(config-rip)# passive-interface ppp 1
The following interfaces can be passive interfaces:
Ethernet interfaces
Ethernet subinterfaces (VLAN interfaces)
PPP interfaces
High-level Data Link Control (HDLC) interfaces
Frame Relay subinterfaces
ATM subinterfaces
loopback interfaces
tunnel interfaces