Portmap and TCP Wrappers

Portmap's implementation of TCP Wrappers does not support host look-ups, which means portmap can not use hostnames to identify hosts. Consequently, access control rules for portmap in hosts.allow or hosts.deny must use IP addresses, or the keyword ALL, for specifying hosts.

Changes to portmap access control rules may not take effect immediately. You may need to restart the portmap service.

Widely used services, such as NIS and NFS, depend on portmap to operate, so be aware of these limitations.