AIS Router AI2524 - Manual (Page 199)

Chapter 9: AI2524 OSI/CLNP Configuration Steps
August 1997 Page 9-41
2524UM
5. Pass packets bound for sid in dom ain47.0006.0200 through serial
0:
clns route 47.0006.0200 sid
CLNS routing updates will not be sent on the serial link; however,
CLNS packets will be sent and received over the serial link.
Configure Variations of the Static Route
These tasks include variations of the clns route global configura-
tion command:
z Bind the next hop to a specified interface and media address when
you do not know the NSAP address of your neighbor. Note that
this version of the clns route command is not literally applied to a
specific interface.
clns route nsap-prefix type number [ snpa-
address ]
z Tell the Cisco IOS software to discard packets with the specified
NSAP prefix.
clns route nsap-prefix discard
z Specify a default prefix.
clns route default nsap-prefix type number
Map NSAP Addresses to Media Addresses
Conceptually, each ES lives in one area. It discovers the nearest IS by
listening to ES-IS packets. Each ES must be able to communicate di
rectly with an IS in its area.
When an ES wants to communicate with another ES, it sends the
packet to any IS on the same medium. The IS looks up the destination
NSAP address and forwards the packet along the best route. If the des-
tination NSAP address is for an ES in another area, the Level1 IS
sends the packet to the nearest Lev el2 IS. The Lev el2 IS forwards the
packet along the best path for the destination area until it gets to a
Level 2 IS that is in the destination area. This IS then forwards the
packet along the best path inside the area until it is delivered to the des-
tination ES.
ESs need to know how to get to a Level1 IS for their area, a nd Level1
ISs need to know all of the ESs that are directly reachable through each
of their interfaces. To provide this information, the routers support the