-also disappear at the same time.
-.SH "TABLE FORMAT"
-The format of the
-.B /etc/hosts.slip
-file is as follows:
-.IP -
-blank lines and lines with a leading # are ignored.
-.IP -
-all other lines should have the form:
-.sp
-.br
-\fIname mode local-address remote-address netmask\fP
-.br
-.sp
-The
-.I name
-is usually the login name of a remote host that wishes to connect by
-dialup slip. More generally it is any key you wish for the address
-and mask parameters specified on that line. The
-.I mode
-is currently unused but must be specified. Use
-.BR normal .
-The remaining parameters have been discussed.
+also disappear at the same time. If there is other processing a site
+would like done on hangup, the file
+.B /etc/slip.logout
+or
+.BI /etc/slip.logout. loginname
+is executed if it exists. It is given the same arguments as the login script.
+.SS Format of /etc/slip.hosts
+Comments (lines starting with a `#') and blank lines are ignored.
+Other lines must start with a
+.I loginname
+but the remaining arguments can be whatever is appropriate for the
+.B slip.login
+file that will be executed for that name.
+Arguments are separated by white space and follow normal
+.BR sh (1)
+quoting conventions (however,
+.I loginname
+cannot be quoted).
+Usually, lines have the form
+.RS
+.I
+loginname local-address remote-address netmask opt-args
+.RE
+where
+.I local-address
+and
+.I remote-address
+are the IP host names or addresses of the local and remote ends of the
+slip line and
+.I netmask
+is the appropriate IP netmask. These arguments are passed
+directly to
+.BR ifconfig (8).
+.I Opt-args
+are optional arguments used to configure the line.
+.SH EXAMPLE
+The normal use of
+.B sliplogin
+is to create a
+.B /etc/passwd
+entry for each legal, remote slip site with
+.B sliplogin
+as the shell for that entry. E.g.,
+.RS
+Sfoo:ikhuy6:2010:1:slip line to foo:/tmp:/etc/sliplogin
+.RE
+(Our convention is to name the account used by remote host
+.I hostname
+as
+.IR Shostname .)
+Then an entry is added to
+.B slip.hosts
+that looks like:
+.RS
+Sfoo `hostname` foo netmask
+.RE
+where
+.I `hostname`
+will be evaluated by
+.B sh
+to the local host name and
+.I netmask
+is the local host IP netmask.
+.PP
+Note that
+.B sliplogin
+must be setuid to root and, while not a security hole, moral defectives
+can use it to place terminal lines in an unusable state and/or deny
+access to legitimate users of a remote slip line. To prevent this,
+a site can create a group, say
+.IR slip ,
+that only the slip login accounts are put in then make sure that
+.B /etc/sliplogin
+is in group
+.I slip
+and mode 4550 (setuid root, only group
+.I slip
+can execute binary).
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