ACCESS CONTROL
tcpd supports a simple form of access control that is
based on pattern matching.
HOST NAME VERIFICATION
tcpd verifies the client host name that is returned by the
address->name DNS server by looking at the host name and address
that are returned by the name->address DNS server. If any dis-
crepancy is detected, tcpd concludes that it is dealing with a
host that pretends to have someone elses host name.