Selecting the
destination only
option causes the router to deny shortcut requests
from any NHRP client if any IP packets are being filtered to the destination address.
If NHRP clients should not be trusted,
destination only
should be selected.
destination only
might be the best option when NHRP clients are non-routers with
multiple IP addresses or non-router clients that transmit packet that originate from
other sources.
NHRP clients that reside in the routers use the NHRP shortcut routes to forward
packets from other sources: therefore, if

source and destination

is configured and
the router receives a shortcut request from a router, the router applies the IP filters
the same way as when
destination only
is selected.
NHRP Access Controls
NHRP access controls for denying shortcuts to certain IP addresses may be defined
by adding those addresses to both the exclude list and disallowed-router-to-router
shortcuts.
ATM Network ID
Since an server may have more than one ATMadapter, it may be connected to two
different or unassociated networks. This must be considered when deciding when
shortcut VCs should be allowed.
Youcan determine which interfaces should be treated as if they are connected to
the same physical ATMnetwork by assigning each ATM interface a Network-ID by
using the set command at the ATM Interface Config> prompt as described in the
“Using and Configuring ATM”chapter in
Software User’s Guide
ATM interfaces with the same Network-ID are considered to belong to the same
network. By default, all ATMinterfaces are assigned to Network-ID 0.
Configuring the LANE Shortcuts Interface (LSI)
The NHRP LANE Shortcut Interface (LSI) is automatically created for each ATM
adapter when NHRP is enabled for the router.The LSI uses default values for the
following parameters.
vESI
vSelector
vUse Best Effort Service for Data VCCs
vPeak Cell Rate of outbound Data VCCs
vSustained Cell Rate of outbound VCCs
vUse ATMadapter’s universally administered MAC address for source
The default values may be modified using the change command from the NHRP
Advanced config>prompt. See “Change” on page363.
Configuring Devices in an ATM Network
If you have a NHRP client/server and its configuration requires you to give the ATM
address of the router NHRP server, you must select the properATM address. You
must use an address associated with an ″ATM interface″in the device, and an IP
address must be assigned to this interface. The last two digits of the router ATM
Using NHRP
Chapter11. Using NHRP 357