Net/Rom Node Information for the Sysop - Part Four

by Andy Nemec, KB9ALN

This is part 4 of a series designed to help node Sysops learn more about the popular TheNET X-1J series of nodes. We'll skip over the more common user commands and devote our discussion to commands used by the Sysop. This month, we look at ALIAS and ARP.


Most every node has an alias - a name other than it's call-sign - that it is known by. TheNet X-1J revision 4 nodes can have the standard network node alias plus 3 other aliases. These are BBSALIAS, DXCALIAS, and HOSTALIAS.

The BBSALIAS is simply another name that the node is known by for BBS purposes. If a station attempts to connect to the BBSALIAS, the node will respond and carry out the BBS connect command (automatically connect to a specified BBS).

In the case of DXCALIAS, the node connects the user to a DX Cluster. HOSTALIAS will connect the user to a local TCP/IP "Host" computer. You don't have to set these other aliases if you don't have these services in your area.

Of course, you would want to set the network node alias. The command syntax is the same for all commands involving an ALIAS. Naturally, you need to be connected to the node as a sysop in order to use these commands. Here's a sumarry:


Clears the alias entry.

ALIAS your_alias_name_here

Will give your node an alias, simple as that.

Note that there are certain checks the node makes to see if your proposed alias is permitted under it's "rules". Changing aliases without careful consideration of the problems it may cause others is discouraged.

Most commonly, the alias is "burned" into the node's EPROM so you probably would only re-enter a node alias if something really bad happened, or it was changed.


Arp is a command closely related to other TCP/IP commands for TheNet X-1J. One of the most recognizable feature of these nodes is the ability to act as a TCP/IP router. That is, it can correctly and automatically route TCP/IP packets (called datagrams) to their intended destination.

What is "ARP"?

ARP means "Address Resoloution Protocol". In the world of TCP/IP, computers are known by their names (called "hostnames") as well as a number (called an IP address). In the Amateur Radio World, Call-signs are used to differentiate stations. ARP bridges this gap by associating an IP address to a Call-Sign. ARP allows the node to properly direct TCP/IP connections toward a particular call-sign-equipped radio transmitter and TNC, eventually reaching the computer.

The Node Sysop maintains a small database in the node (called an "ARP Table") that it uses to remember which call-sign goes with which IP address. ARP, when used as a node command, is used to manipulate this database. Sound confusing? It's really pretty simple when you take it step-by-step.

For now, let's just assume that WX9APR has an IP address of All we have to do is to tell this to the node. Let's put WX9APR into a node's ARP Table. We'd use the command form of:


The First number appearing after the ARP command,, is the IP address belonging to WX9APR.

The + indicates you want to add it to the list.

The P indicates that you want the node to Publish this arp entry - tell it to other computers that are listening on the frequency.

AX25 tells the node to use the AX.25 protocol set (the Amateur Packet Standard) to talk to WX9APR, which is the call-sign used to connect.

The Last entry, DG, means to use the "Datagram" mode. The Datagram mode uses end-to-end packet acknowledgement. There is one other choice, VC. This means that the connection is to be a "Virtual Circuit" type. These connections are hop-to-hop acknowledged. There are special uses for both. The general rule seems to be to use DG on reliable paths, and VC when the path is error-prone.

This is fine, we have WX9APR on the list. What happens when he decides to change call-signs, and we have to remove the old one from the list? That one is easy enough:

ARP - AX25

From there, you can add that address on a different call-sign using the ARP + variant of the command.

Any incorrect syntax using the ARP command can make things interesting. One common mistake is not entering enough information when dropping a station from the list. Forgetting to enter the IP Address, for example, will turn ARP off entirely. Turning it back on is simple: ARP + Will do it.


by itself, as you have probably guessed, totally disables ARP.

That's all for this part. Two of the final installments in this series will sumarrize what it takes to get the TCP/IP functions operating on TheNet X-1JR4 nodes. Next time, we'll continue our alphabetical exploration of the Sysop commands for these nodes.

Proceed with Part 5

Back to Part 3

Back to the Node Sysop Information Index

Back to the WAPR Home Page