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Running The Network Information Server

apcupsd maintains STATUS and EVENTS data concerning the UPS and its operation. This information can be obtained over the network using either apcnisd or apcupsd's internal network information server, which is essentially the same code as apcnisd but compiled into apcupsd. Clients on the network make a connection to the information server and send requests for status or events data, which the server then transmits to them.

As of apcupsd 3.12.x, the NIS server runs only as a child of apcupsd. It cannot be run standalone or from INETD.

This is probably the simplest way to run the network information server. To do so, you simply make sure the NETSERVER directive in /etc/apcupsd/apcupsd.conf is on, and then stop and restart apcupsd. It will automatically create the server thread to handle network clients. Note, the above modification should not be necessary if you use the default apcupsd.conf, since it is already turned on.

Although this method is simple, it affords no protection from the outside world accessing your network server unless you are behind a firewall. In addition, if there is a bug in the network server code, or if a malicious user sends bad data, it may be possible for apcnis to die, in which case, though it is not supposed to, apcupsd may also exit, thus leaving your machine without shutdown protection. In addition, since apcupsd is running at root level, all threads or any child process will do so also. That being said, most of us prefer to run the server this way.

With apcupsd version 3.8.2 and later, you may enable the TCP Libwrap subroutines to add additional security. In this case, access to the network server will be controlled by the statements you put in /etc/hosts.allow.


next up previous contents index
Next: apcupsd System Logging Up: Apcupsd User's Guide Previous: Support for SNMP UPSes   Contents   Index
2009-11-06