Title: DECbrouter90 OSI CLNP over X.25 using NSAP-prefix for static routes.

Product: DECbrouter90 V9.14/10.x

Question: How do I configure the DECbrouter90 to route OSI packets across X.25
          to an NSAP prefix on a per-interface basis?

Solution:


        There are 3 methods of transferring OSI CLNP data over X.25: 

1. Static routes to the NSAP of End Systems

2. Static routes to a NSAP-prefix on a router wide basis 

3. Static routes to a NSAP-prefix on an individual circuit basis. 


        This is an example of how to setup a static route to a NSAP-prefix on a
per interface basis.

        This is an example configuration for the DECbrouter 90 showing how to
transport OSI CLNP (ISO8473) over a X.25 WAN circuit. The DECbrouter 90/Cisco
only supports DA Dynamically Assigned Datalinks over X.25 for ISO CLNS. This 
means that no routing packets are exchanged over this circuit and all ESs 
reachable on either side of the PSDN must be mapped via the CLNS ES-NEIGHBOR 
command. When a connect request is issued from node NEIL to node YOUNG, DBR90 
BRUTH places a X.25 call to BRUTG which in turn routes the request out it's 
ethernet circuit. This call will drop after the amount of idle time specified
in the x25 idle param or upon receipt of ES disconnect.


        ---------------------------------------------------------
        |                    Node NEIL                          |
        |               NSAP addresses configured               |
        |  [ DNA_OSInetwork , 49::00-03:AA-00-04-00-02-0C:21 ]  |
        |  [ DNA_OSInetwork , 49::00-03:08-00-2B-A3-78-5A:21 ]  |
        |  [ DNA_OSInetwork , 49::00-03:AA-00-04-00-02-0C:20 ]  |
        |  [ DNA_OSInetwork , 49::00-03:08-00-2B-A3-78-5A:20 ]  |
        |                                                       |
        ---------------------------------------------------------
                                |                  Ethernet LAN
        ---------------------------------------------------------
                                |
                                | E0
        ---------------------------------------------------------
        |!              DECbrouter 90                           |
        |hostname BRUTH                                         |
        |!                                                      |
        |clns routing                                           |
        |!                                                      |
        |! Enables CLNS routing                                 |
        |!                                                      |
        |interface Ethernet 0                                   |
        |clns router isis                                       |
        |!                                                      |
        |! Enables CLNS routing on Ethernet 0                   |
        |!                                                      |
        |interface Serial 0                                     |
        |encapsulation X25                                      |
        |x25 address 123456789012                               |
        |X25 idle 5                                             |
        |!                                                      |
        |! Setup X.25 params;                                   |
        |!                                                      |
        |clns router isis                                       |
        |!                                                      |
        |! Enable CLNS on Inter Serial 0                        |
        |!                                                      |
        |clns is-neighbor 49.0004.0800.2BA1.F952.00 210987654321|
        |!                                                      |
        |! Setup static routes to OSI IS on the PSDN            |
        |!                                                      |
        |router isis                                            |
        |net 49.0003.0800.2BA1.4434.00                          |
        |!                                                      |
        |! Configure the DBR90s NSAP address or NET             |
        |!                                                      |
        |clns route 49.0004 Serial0 210987654321                |
        |!                                                      |
        |! MAPs NSAP prefix to particular interface, which in   |
        |! turn in mapped to a OSI IS on PSDN                   |
        |!                                                      |
        ---------------------------------------------------------       
                                / S0
                                \
                        (X.25 Cloud/PSDN)
                                /
                                \ S0
        ---------------------------------------------------------
        |!              DECbrouter 90                           |
        |hostname BRUTG                                         |
        |!                                                      |
        |clns routing                                           |
        |!                                                      |
        |! Enables CLNS routing                                 |
        |!                                                      |
        |interface Ethernet 0                                   |
        |clns router isis                                       |
        |!                                                      |
        |! Enables CLNS routing on Ethernet 0                   |
        |!                                                      |
        |interface Serial 0                                     |
        |encapsulation X25                                      |
        |x25 address 210987654321                               |
        |X25 idle 5                                             |
        |!                                                      |
        |! Setup X.25 params;                                   |
        |!                                                      |
        |clns router isis                                       |
        |!                                                      |
        |! Enable CLNS on Inter Serial 0                        |
        |!                                                      |
        |clns is-neighbor 49.0003.0800.2BA1.4434.00 123456789012|
        |!                                                      |
        |! Setup static routes to OSI IS on the PSDN            |
        |!                                                      |
        |router isis                                            |
        |net 49.0004.0800.2BA1.F952.00                          |
        |!                                                      |
        |! Configure the DBR90s NSAP address or NET             |
        |!                                                      |
        |clns route 49.0003 Serial0 123456789012
        |!                                                      |
        |! MAPs NSAP prefix to particular interface, which in   |
        |! turn in mapped to a OSI IS on PSDN                   |
        |!                                                      |
        ---------------------------------------------------------       
                                | E0
                                |                  Ethernet LAN
        ---------------------------------------------------------
                                |
        ---------------------------------------------------------
        |                    Node YOUNG                         |
        |               NSAP addresses configured               |
        |  [ DNA_OSInetwork , 49::00-04:AA-00-04-00-E7-13:21 ]  |
        |  [ DNA_OSInetwork , 49::00-04:08-00-2B-39-C9-27:21 ]  |
        |  [ DNA_OSInetwork , 49::00-04:AA-00-04-00-E7-13:20 ]  |
        |  [ DNA_OSInetwork , 49::00-04:08-00-2B-39-C9-27:20 ]  |
        |                                                       |
        ---------------------------------------------------------


BRUTH#show isis route
show isis route

IS-IS Level-1 Routing Table - Version 5
System Id       Next-Hop        SNPA            Interface   Metric  State
AA00.0400.020C  AA00.0400.020C  aa00.0400.020c  Ethernet0   10      Up
0800.2BA1.4434  0000.0000.0000  --              --          0       Up
0800.2BA3.785A  0800.2BA3.785A  aa00.0400.020c  Ethernet0   10      Up
BRUTH#show clns route
show clns route

CLNS Prefix Routing Table
49.0003 [110/0]
  via 0800.2BA1.4434, IS-IS, Up
49.0004 [10/0]
  via 210987654321, Serial0, Static
49.0003.0800.2BA1.4434.00, Local NET Entry


BRUTG#show isis route
show isis route

IS-IS Level-1 Routing Table - Version 3
System Id       Next-Hop        SNPA            Interface   Metric  State
AA00.0400.E713  AA00.0400.E713  aa00.0400.e713  Ethernet0   10      Up
0800.2BA1.F952  0000.0000.0000  --              --          0       Up
0800.2B39.C927  0800.2B39.C927  aa00.0400.e713  Ethernet0   10      Up
BRUTG#show clns route
show clns route

CLNS Prefix Routing Table
49.0004 [110/0]
  via 0800.2BA1.F952, IS-IS, Up
49.0003 [10/0]
  via 123456789012, Serial0, Static
49.0004.0800.2BA1.F952.00, Local NET Entry