ypserv.conf is an ASCII file which contains some options for ypserv. It also contains a list of rules for special host and map access for ypserv and rpc.ypxfrd. This file will be read by ypserv and rpc.ypxfrd at startup, or when receiving a SIGHUP signal.
There is one entry per line. If the line is a option line, the format is:
The line for an access rule has the format:
All rules are tried one by one. If no match is found, access to a map is allowed.
Following options exist:
- files: 30
This option specifies, how many database files should be cached by ypserv. If 0 is specified, caching is disabled. Decreasing this number is only possible, if ypserv is restarted.
- trusted_master: server
If this option is set on a slave server, new maps from the host server will be accepted as master. The default is, that no trusted master is set and new maps will not be accepted.
- slp: [yes|<no>|domain]
If this option is enabled and SLP support compiled in, the NIS server registers itself on a SLP server. If the variable is set to domain, an attribute domain with a comma seperated list of supported domainnames is set. Else this attribute will not be set. The default is "no" (disabled).
- xfr_check_port: [<yes>|no]
With this option enabled, the NIS master server have to run on a port < 1024. The default is "yes" (enabled).
The field descriptions for the access rule lines are:
IPv4 only address. Wildcards are allowed. This rules are ignored for IPv6, which means it is better to not use this option at all anymore.
131.234. = 188.8.131.52/255.255.0.0 184.108.40.206/255.255.254.0
specifies the domain, for which this rule should be applied. An asterix as wildcard is allowed.
name of the map, or asterisk for all maps.
one of none, port, deny:
always allow access.
allow access if from port < 1024. Otherwise do not allow access.
deny access to this map.
The access rules for special maps are no real improvement in security, but they make the life a little bit harder for a potential hacker.
Solaris clients don't use privileged ports. All security options which depend on privileged ports cause big problems on Solaris clients.
Thorsten Kukuk <email@example.com>