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AlterPatch ACS Console Server

Posted <2018-02-11 Sun 15:27> by Aaron S. Jackson.

In the machine room at uni there is an AlterPath console server which for a long time was hooked up to a VT220. Unfortunately the flyback died in this terminal. I recently won on eBay three in-need-of-attention VT420 terminals, one of them has made its way into this room, and is now hooked up to the console server.

I had looked about for a console previously, but mainly the DECserver ones. Either the model was wrong, such as only supporting DECnet or it had to boot off a tftp or MOP server (not so much a problem, just an inconvenience). I decided to search eBay for an AlterPath console server and found one which I won for £15. Unfortunately it only had four ports, which I have quickly managed to saturate. I have it hooked up to my router, switch, mail server and another router (a Cisco 2621 which I like because it has DECnet support).

Initially I thought I would hook up one of the ports to my PDP-11/73 so I wouldn't have to switch on a terminal to boot up catbert. There is something a bit wrong though and I can't find the right configuration. It's standard 9600 baud, and my terminals are set to 8N1, but for some reason once UNIX starts it stops displaying characters correctly. I thought it might be something to do with parity, but that did not help.

Anyway, the AlterPath is actually quite interesting. It loads its root file system into memory (which is < 40MB), and then copies across the configurations and reloads things. Mine has 128MB of RAM and a 48MHz MIPS 8 CPU. The power consumption is under 8W. It can be configured via the web interface or through configuration files, which can then be saved to permanent storage by running saveconf.

One of the things I could most interesting was the ability to assign an IP address to each serial port, each running on port 23/tcp for example, for telnet. However, it is easy to think you have damaged the configuration when you undo this since it stops working if you remove these settings. To fix it you have to go into ~/etc/postslave/pslave.conf and remove the lines at the end which were added for IP bindings. Probably a good idea not to mess about with the web panel in this case. It also supports a variety of authentication methods, including Kerberos, LDAP and NIS. I'm not using any of these, but I can see how this kind of option would be very helpful in a large environment.

I have now run into an ugly problem of having a stack of gear sitting in a rack, sliding about. Perhaps I will get one of the cheap-ish 6U to 9U wall racks off eBay for about £45. Here is the mess at the moment:

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