HP General IO Connectivity manual Syntax for SVCs, Syntax for PVCs

Troubleshooting

Configuration and Troubleshooting Commands

reach a host with a particular IP address. Reverse mapping reverses the order of translation. The default file name and directory for the mapping table is /etc/x25/ip_to_x121_map.

When the packet is outbound, the IP address is mapped to the X.121 address that is associated with it in the IP map file. When the packet is inbound, the X.121 address is mapped to the IP address of the same destination host. This is called “reverse mapping.” The table is not used when IP packets are transmitted to X.25 over DDN. In this case, the DDN-specific mapping algorithm is used instead. See DDN X.25 Host Interface Specification (BBN83).

There must be an entry in the mapping table for each host you want to communicate with over a direct-connect X.25 network. If the host is connected through a gateway, you only need an entry for the gateway (containing the IP and X.121 addresses of the gateway).

NOTE	If the destination host is only reachable through a gateway, you must
	have a route to that host (a host or a net route).

The IP address in the table must belong to the same IP subnet as a configured card in your system, and this card must be already started when you initialize IP routing with the command:

/usr/sbin/x25init -a /etc/x25/ip_to_x121_map

If the IP address does not correspond to a configured card, the X.25 product does not know which interface to use to send packets. Therefore, you must place this information in your /etc/x25/ip_to_x121_map file by adding the x25_card_device parameter as shown in the syntax example below. This is a manual procedure that cannot be done in SAM.

Syntax for SVCs

IP_address X.121_address [{+URC-URC}][+ARC-ARC}] device=x25_card_device, packet_size, window_size [CUG=n]

Syntax for PVCs

IP_address X.121_address pvc=n name=prog_access_name

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