diff --git a/etc/rc.d/jail b/etc/rc.d/jail
index b4b051fa71d1..0edf078dd3d9 100644
--- a/etc/rc.d/jail
+++ b/etc/rc.d/jail
@@ -33,9 +33,10 @@ init_variables()
 	jail_procdir="${jail_rootdir}/proc"
 	eval jail_hostname=\"\$jail_${_j}_hostname\"
 	eval jail_ip=\"\$jail_${_j}_ip\"
+	eval jail_interface=\"\${jail_${_j}_interface:-${jail_interface}}\"
 	eval jail_exec=\"\$jail_${_j}_exec\"
-	eval jail_exec_start=\"\$jail_${_j}_exec_start\"
-	eval jail_exec_stop=\"\$jail_${_j}_exec_stop\"
+	eval jail_exec_start=\"\${jail_${_j}_exec_start:-${jail_exec_start}}\"
+	eval jail_exec_stop=\"\${jail_${_j}_exec_stop:-${jail_exec_stop}}\"
 	if [ -n "${jail_exec}" ]; then
 		#   simple/backward-compatible execution
 		jail_exec_start="${jail_exec}"
@@ -51,20 +52,20 @@ init_variables()
 	fi
 
 	# The default jail ruleset will be used by rc.subr if none is specified.
-	eval jail_ruleset=\"\$jail_${_j}_devfs_ruleset\"
-	eval jail_devfs=\"\$jail_${_j}_devfs_enable\"
+	eval jail_ruleset=\"\${jail_${_j}_devfs_ruleset:-${jail_devfs_ruleset}}\"
+	eval jail_devfs=\"\${jail_${_j}_devfs_enable:-${jail_devfs_enable}}\"
 	[ -z "${jail_devfs}" ] && jail_devfs="NO"
-	eval jail_fdescfs=\"\$jail_${_j}_fdescfs_enable\"
+	eval jail_fdescfs=\"\${jail_${_j}_fdescfs_enable:-${jail_fdescfs_enable}}\"
 	[ -z "${jail_fdescfs}" ] && jail_fdescfs="NO"
-	eval jail_procfs=\"\$jail_${_j}_procfs_enable\"
+	eval jail_procfs=\"\${jail_${_j}_procfs_enable:-${jail_procfs_enable}}\"
 	[ -z "${jail_procfs}" ] && jail_procfs="NO"
 
-	eval jail_mount=\"\$jail_${_j}_mount_enable\"
+	eval jail_mount=\"\${jail_${_j}_mount_enable:-${jail_mount_enable}}\"
 	[ -z "${jail_mount}" ] && jail_mount="NO"
 	# "/etc/fstab.${_j}" will be used for {,u}mount(8) if none is specified.
-	eval jail_fstab=\"\$jail_${_j}_fstab\"
+	eval jail_fstab=\"\${jail_${_j}_fstab:-${jail_fstab}}\"
 	[ -z "${jail_fstab}" ] && jail_fstab="/etc/fstab.${_j}"
-	eval jail_flags=\"\$jail_${_j}_flags\"
+	eval jail_flags=\"\${jail_${_j}_flags:-${jail_flags}}\"
 	[ -z "${jail_flags}" ] && jail_flags="-l -U root"
 
 	# Debugging aid
@@ -75,6 +76,7 @@ init_variables()
 	debug "$_j mount enable: $jail_mount"
 	debug "$_j hostname: $jail_hostname"
 	debug "$_j ip: $jail_ip"
+	debug "$_j interface: $jail_interface"
 	debug "$_j root: $jail_rootdir"
 	debug "$_j devdir: $jail_devdir"
 	debug "$_j fdescdir: $jail_fdescdir"
@@ -162,6 +164,9 @@ jail_start()
 			echo -n " [${jail_hostname} already running (/var/run/jail_${_jail}.id exists)]"
 			continue;
 		fi
+		if [ -n ${jail_interface} ]; then
+			ifconfig ${jail_interface} alias ${jail_ip} netmask 255.255.255.255
+		fi
 		if checkyesno jail_mount; then
 			info "Mounting fstab for jail ${_jail} (${jail_fstab})"
 			if [ ! -f "${jail_fstab}" ]; then
@@ -234,6 +239,9 @@ jail_stop()
 				jail_umount_fs
 				echo -n " $jail_hostname"
 			fi
+			if [ -n ${jail_interface} ]; then
+				ifconfig ${jail_interface} -alias ${jail_ip}
+			fi
 			rm /var/run/jail_${_jail}.id
 		else
 			echo "cannot stop jail ${_jail}. No jail id in /var/run"
diff --git a/share/man/man5/rc.conf.5 b/share/man/man5/rc.conf.5
index 89b724cb7ad5..fa05c721d072 100644
--- a/share/man/man5/rc.conf.5
+++ b/share/man/man5/rc.conf.5
@@ -24,7 +24,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd February 13, 2006
+.Dd April 8, 2006
 .Dt RC.CONF 5
 .Os
 .Sh NAME
@@ -2975,13 +2975,184 @@ you would have the following dependent variables:
 jail_vjail_hostname="jail.example.com"
 jail_vjail_ip="192.168.1.100"
 jail_vjail_rootdir="/var/jails/vjail/root"
-jail_vjail_exec="/bin/sh /etc/rc"
 .Ed
 .Pp
-The last one is optional.
-It defaults to
-.Pa /etc/rc
-if it is not set.
+.It Va jail_flags
+.Pq Vt str
+Unset by default.
+When set, use as default value for
+.Va jail_ Ns Ao Ar jid Ac Ns Va _flags
+for every jail in
+.Va jail_list .
+.It Va jail_interface
+.Pq Vt str
+Unset by default.
+When set, use as default value for
+.Va jail_ Ns Ao Ar jid Ac Ns Va _interface
+for every jail in
+.Va jail_list .
+.It Va jail_fstab
+.Pq Vt str
+Unset by default.
+When set, use as default value for
+.Va jail_ Ns Ao Ar jid Ac Ns Va _fstab
+for every jail in
+.Va jail_list .
+.It Va jail_mount_enable
+.Pq Vt bool
+Set to
+.Dq Li NO
+by default.
+When set to
+.Dq Li YES ,
+sets
+.Va jail_ Ns Ao Ar jid Ac Ns Va _mount_enable
+to YES by default for every jail in
+.Va jail_list .
+.It Va jail_devfs_ruleset
+.Pq Vt str
+Unset by default.
+When set, sets
+.Va jail_ Ns Ao Ar jid Ac Ns Va _devfs_ruleset
+to given value for every jail in
+.Va jail_list .
+.It Va jail_devfs_enable
+.Pq Vt bool
+Set to
+.Dq Li NO
+by default.
+When set to
+.Dq Li YES ,
+sets
+.Va jail_ Ns Ao Ar jid Ac Ns Va _devfs_enable
+to YES by default for every jail in
+.Va jail_list .
+.It Va jail_fdescfs_enable
+.Pq Vt bool
+Set to
+.Dq Li NO
+by default.
+When set to
+.Dq Li YES ,
+sets
+.Va jail_ Ns Ao Ar jid Ac Ns Va _fdescfs_enable
+to YES by default for every jail in
+.Va jail_list .
+.It Va jail_procfs_enable
+.Pq Vt bool
+Set to
+.Dq Li NO
+by default.
+When set to
+.Dq Li YES ,
+sets
+.Va jail_ Ns Ao Ar jid Ac Ns Va _fdescfs_enable
+to YES by default for every jail in
+.Va jail_list .
+.It Va jail_exec_start
+.Pq Vt str
+Unset by default.
+When set, use as default value for
+.Va jail_ Ns Ao Ar jid Ac Ns Va _exec_start
+for every jail in 
+.Va jail_list .
+.It Va jail_exec_stop
+Unset by default.
+When set, use as default value for
+.Va jail_ Ns Ao Ar jid Ac Ns Va _exec_stop
+for every jail in
+.Va jail_list .
+.It Va jail_ Ns Ao Ar jid Ac Ns Va _rootdir
+.Pq Vt str
+Unset by default.
+Set to the root directory used by jail
+.Va jid .
+.It Va jail_ Ns Ao Ar jid Ac Ns Va _hostname
+.Pq Vt str
+Unset by default.
+Set to the fully qualified domain name (FQDN) assigned to jail
+.Va jid .
+.It Va jail_ Ns Ao Ar jid Ac Ns Va _ip
+.Pq Vt str
+Unset by default.
+Set to the IP address assigned to jail
+.Va jid .
+.It Va jail_ Ns Ao Ar jid Ac Ns Va _flags
+.Pq Vt str
+Set to
+.Dq Li -l -U root
+by default.
+These are flags to pass to
+.Xr jail .
+.It Va jail_ Ns Ao Ar jid Ac Ns Va _interface
+.Pq Vt str
+Unset by default.
+When set, sets the interface to use when setting IP address alias.
+Note that the alias is created at jail startup and removed at jail shutdown.
+.It Va jail_ Ns Ao Ar jid Ac Ns Va _fstab
+.Pq Vt str
+Set to
+.Pa /etc/fstab. Ns Ao Ar jid Ac
+by default.
+This is the file system information file to use for jail
+.Va jid .
+.It Va jail_ Ns Ao Ar jid Ac Ns Va _mount_enable
+.Pq Vt bool
+Set to
+.Dq Li NO
+by default.
+When set to
+.Dq Li YES ,
+mount all file systems from
+.Va jail_ Ns Ao Ar jid Ac Ns Va _fstab
+at jail startup.
+.It Va jail_ Ns Ao Ar jid Ac Ns Va _devfs_ruleset
+.Pq Vt str
+Unset by default.
+When set, defines the device file system ruleset file to use for jail
+.Va jid .
+.It Va jail_ Ns Ao Ar jid Ac Ns Va _devfs_enable
+.Pq Vt bool
+Set to
+.Dq Li NO
+by default.
+When set to
+.Dq Li YES ,
+mount the device file system inside jail
+.Ar jid
+at jail startup.
+.It Va jail_ Ns Ao Ar jid Ac Ns Va _fdescfs_enable
+.Pq Vt bool
+Set to
+.Dq Li NO
+by default.
+When set to
+.Dq Li YES ,
+mount the file-descriptor file system inside jail
+.Ar jid
+at jail startup.
+.It Va jail_ Ns Ao Ar jid Ac Ns Va _procfs_enable
+.Pq Vt bool
+Set to
+.Dq Li NO
+by default.
+When set to
+.Dq Li YES ,
+mount the process file system inside jail
+.Ar jid
+at jail startup.
+.It Va jail_ Ns Ao Ar jid Ac Ns Va _exec_start
+.Pq Vt str
+Set to
+.Dq Li /bin/sh /etc/rc
+by default.
+This is the command executed at jail startup.
+.It Va jail_ Ns Ao Ar jid Ac Ns Va _exec_stop
+.Pq Vt str
+Set to
+.Dq Li /bin/sh /etc/rc.shutdown
+by default.
+This is the command executed at jail shutdown.
 .It Va jail_set_hostname_allow
 .Pq Vt bool
 If set to