Add somewhat generic dhcpd addon snippets.

15 files changed, 468 insertions, 0 deletions

diff --git a/dhcp3/README b/dhcp3/README
new file mode 100644
index 0000000..88d00e0
--- /dev/null
+++ b/dhcp3/README
@@ -0,0 +1,22 @@
+These are general preparation for support of each feature:
+
+    dhcpd.etherboot
+    dhcpd.fai
+    dhcpd.pxe
+    dhcpd.pxelinux
+    ...
+
+They must not introduce configuration parameters that interfere with
+other hosts. Ideally they must not conflict with each other, but that
+may be unavoidable (at least include a note about conflicting files).
+
+
+These are host-specific option, that must be included within a host or
+group clause:
+
+    dhcpd.etherboot.host
+    dhcpd.etherboot.host-udhcp
+    dhcpd.pxe.host
+    dhcpd.pxe.host-mcast
+    dhcpd.pxelinux.host
+    ...
diff --git a/dhcp3/dhcp3-cilent.cf b/dhcp3/dhcp3-cilent.cf
new file mode 100755
index 0000000..4231416
--- /dev/null
+++ b/dhcp3/dhcp3-cilent.cf
@@ -0,0 +1,19 @@
+#! /usr/bin/cfengine -qf
+
+control:
+	OutputPrefix	= ("${cf_prefix}")
+	actionsequence	= ( editfiles )
+	EditfileSize	= ( 10000 )
+
+editfiles:
+    any::
+	{ /etc/dhcp3/dhclient-script
+		#
+		# Set hostname to reverse lookup of IP
+		#
+		WarnIfNoLineMatching "^[[:blank:]]+([A-Z]+\|)*BOUND(\|[A-Z]+)*\)"
+		LocateLineMatching "^[[:blank:]]+([A-Z]+\|)*BOUND(\|[A-Z]+)*\)"
+		BeginGroupIfNoLineMatching "^AllowShutdown=All"
+			ReplaceLineWith "AllowShutdown=All"
+		EndGroup
+	}
diff --git a/dhcp3/dhcpd.etherboot b/dhcp3/dhcpd.etherboot
new file mode 100644
index 0000000..1f3ef62
--- /dev/null
+++ b/dhcp3/dhcpd.etherboot
@@ -0,0 +1,73 @@
+# This ISC dhcpd 3.x config snippet is inspired by initrd code in
+# contrib area of etherboot source (dhcpd.conf.etherboot.include).
+
+# Usage:
+#
+# include "/etc/local-COMMON/dhcp3/dhcpd.etherboot";
+#
+# # (...common options...)
+#
+# # Accepted hosts (syntax is "1:" + MAC address)
+# subclass "etherboot-hosts" 00:01:02:03:04:05;
+# subclass "etherboot-hosts" 00:01:02:03:04:06 { fixed-address 192.168.1.101; another-option "bla bla"; }
+#
+
+# image-n syntax: "label:server:gateway:filename:passwd:flags:cmdline"
+
+option space etherboot;
+
+option etherboot.extensions-path	code 18 = string;
+option etherboot.magic			code 128 = string;
+option etherboot.kernel-cmdline		code 129 = text;
+option etherboot.netdevice		code 130 = text;	# Root NFS device for multihomed diskless clients (example: "eth1")
+option etherboot.menu-opts		code 160 = text;
+option etherboot.nic-dev-id		code 175 = string;
+option etherboot.menu-selection		code 176 = unsigned integer 8;
+option etherboot.motd-1			code 184 = text;
+option etherboot.motd-2			code 185 = text;
+option etherboot.motd-3			code 186 = text;
+option etherboot.motd-4			code 187 = text;
+option etherboot.motd-5			code 188 = text;
+option etherboot.motd-6			code 189 = text;
+option etherboot.motd-7			code 190 = text;
+option etherboot.motd-8			code 191 = text;
+option etherboot.image-1		code 192 = text;
+option etherboot.image-2		code 193 = text;
+option etherboot.image-3		code 194 = text;
+option etherboot.image-4		code 195 = text;
+option etherboot.image-5		code 196 = text;
+option etherboot.image-6		code 197 = text;
+option etherboot.image-7		code 198 = text;
+option etherboot.image-8		code 199 = text;
+option etherboot.image-9		code 200 = text;
+option etherboot.image-10		code 201 = text;
+option etherboot.image-11		code 202 = text;
+option etherboot.image-12		code 203 = text;
+option etherboot.image-13		code 204 = text;
+option etherboot.image-14		code 205 = text;
+option etherboot.image-15		code 206 = text;
+option etherboot.image-16		code 207 = text;
+option etherboot.kmod			code 254 = string;
+
+#class "etherboot-hosts" {
+#	match pick-first-value (option dhcp-client-identifier, hardware);
+#}
+
+# Etherboot sends a string to identify the NIC in etherboot.nic-dev-id.
+# For PCI NICs, this string is of the form "PCI:vvvv:dddd" where vvvv is the 
+# vendor identifier and dddd the device identifier, in lower-case ASCII hex.
+#
+# Normally you simply include the file generated by mknbi-set.
+#
+# Here's a sample output of that tool:
+#
+#if substring ( option vendor-class-identifier, 0, 9 ) = "Etherboot" {
+#  if exists etherboot.nic-dev-id {
+#    # Legacy nic-dev-id mechanism: there are some DLink DFE538 cards in circulation that
+#    # predated the change to the new nic-dev-id binary structure
+#    if option etherboot.nic-dev-id = "PCI:1186:1300" { option etherboot.kmod "8139too"; }
+#
+#    # Generated from mknbi-set.conf
+#
+#  }
+#}
diff --git a/dhcp3/dhcpd.etherboot-legacy b/dhcp3/dhcpd.etherboot-legacy
new file mode 100644
index 0000000..0261498
--- /dev/null
+++ b/dhcp3/dhcpd.etherboot-legacy
@@ -0,0 +1,83 @@
+# Legacy site-local option support
+# If client does not include an etherboot-encapsulated-options field in its DHCPREQUEST, then
+# it will not understand etherboot-encapsulated-options in the DHCPACK and so we must send
+# back the options as site-local options (i.e. not encapsulated).
+# Note: we need do this only for options that existed prior to the switch to encapsulation.
+#
+# For some reason the encapsulation option makes isc-dhcpd-V3.0.1rc11
+# crash (too much info encapsulated?).
+
+option etherboot-encapsulated-options	code 150 = encapsulate etherboot;
+
+# Some of these options are untested and may clash with reserved code
+# numbers when legacy, so they have been commented out here.
+
+#option legacy-etherboot-extensions-path	code 18 = string;
+option legacy-etherboot-magic		code 128 = string;
+option legacy-etherboot-kernel-cmdline	code 129 = string;
+#option legacy-etherboot-netdevice	code 130 = text;
+option legacy-etherboot-menu-opts	code 160 = string;
+option legacy-etherboot-menu-selection	code 176 = unsigned integer 8;
+option legacy-etherboot-motd-1		code 184 = string;
+option legacy-etherboot-motd-2		code 185 = string;
+option legacy-etherboot-motd-3		code 186 = string;
+option legacy-etherboot-motd-4		code 187 = string;
+option legacy-etherboot-motd-5		code 188 = string;
+option legacy-etherboot-motd-6		code 189 = string;
+option legacy-etherboot-motd-7		code 190 = string;
+option legacy-etherboot-motd-8		code 191 = string;
+option legacy-etherboot-image-1		code 192 = string;
+option legacy-etherboot-image-2		code 193 = string;
+option legacy-etherboot-image-3		code 194 = string;
+option legacy-etherboot-image-4		code 195 = string;
+option legacy-etherboot-image-5		code 196 = string;
+option legacy-etherboot-image-6		code 197 = string;
+option legacy-etherboot-image-7		code 198 = string;
+option legacy-etherboot-image-8		code 199 = string;
+option legacy-etherboot-image-9		code 200 = string;
+option legacy-etherboot-image-10	code 201 = string;
+option legacy-etherboot-image-11	code 202 = string;
+option legacy-etherboot-image-12	code 203 = string;
+option legacy-etherboot-image-13	code 204 = string;
+option legacy-etherboot-image-14	code 205 = string;
+option legacy-etherboot-image-15	code 206 = string;
+option legacy-etherboot-image-16	code 207 = string;
+#option legacy-etherboot-kmod		code 254 = string;
+
+if (
+	( substring ( option vendor-class-identifier, 0, 9 ) = "Etherboot" )
+	and
+	( not exists etherboot-encapsulated-options )
+) {
+#	option legacy-etherboot-extensions-path	= config-option etherboot.extensions-path;
+	option legacy-etherboot-magic		= config-option etherboot.magic;
+	option legacy-etherboot-kernel-cmdline	= config-option etherboot.kernel-cmdline;
+#	option legacy-etherboot-netdevice	= config-option etherboot.netdevice;
+	option legacy-etherboot-menu-opts	= config-option etherboot.menu-opts;
+	option legacy-etherboot-menu-selection	= config-option etherboot.menu-selection;
+	option legacy-etherboot-motd-1		= config-option etherboot.motd-1;
+	option legacy-etherboot-motd-2		= config-option etherboot.motd-2;
+	option legacy-etherboot-motd-3		= config-option etherboot.motd-3;
+	option legacy-etherboot-motd-4		= config-option etherboot.motd-4;
+	option legacy-etherboot-motd-5		= config-option etherboot.motd-5;
+	option legacy-etherboot-motd-6		= config-option etherboot.motd-6;
+	option legacy-etherboot-motd-7		= config-option etherboot.motd-7;
+	option legacy-etherboot-motd-8		= config-option etherboot.motd-8;
+	option legacy-etherboot-image-1		= config-option etherboot.image-1;
+	option legacy-etherboot-image-2		= config-option etherboot.image-2;
+	option legacy-etherboot-image-3		= config-option etherboot.image-3;
+	option legacy-etherboot-image-4		= config-option etherboot.image-4;
+	option legacy-etherboot-image-5		= config-option etherboot.image-5;
+	option legacy-etherboot-image-6		= config-option etherboot.image-6;
+	option legacy-etherboot-image-7		= config-option etherboot.image-7;
+	option legacy-etherboot-image-8		= config-option etherboot.image-8;
+	option legacy-etherboot-image-9		= config-option etherboot.image-9;
+	option legacy-etherboot-image-10	= config-option etherboot.image-10;
+	option legacy-etherboot-image-11	= config-option etherboot.image-11;
+	option legacy-etherboot-image-12	= config-option etherboot.image-12;
+	option legacy-etherboot-image-13	= config-option etherboot.image-13;
+	option legacy-etherboot-image-14	= config-option etherboot.image-14;
+	option legacy-etherboot-image-15	= config-option etherboot.image-15;
+	option legacy-etherboot-image-16	= config-option etherboot.image-16;
+#	option legacy-etherboot-kmod		= config.option etherboot.kmod;
+}
diff --git a/dhcp3/dhcpd.etherboot-pxe b/dhcp3/dhcpd.etherboot-pxe
new file mode 100644
index 0000000..e953208
--- /dev/null
+++ b/dhcp3/dhcpd.etherboot-pxe
@@ -0,0 +1,29 @@
+# This ISC dhcpd 3.x config snippet is inspired by initrd code in
+# contrib area of etherboot source (dhcpd.conf.etherboot.include).
+
+# Usage:
+#
+# include "/etc/local-COMMON/dhcp3/dhcpd.etherboot";
+# include "/etc/local-COMMON/dhcp3/dhcpd.etherboot-pxe";
+#
+# (...common options...)
+#
+# subclass "etherboot-pxe-hosts" 00:01:02:03:04:05;
+# subclass "etherboot-pxe-hosts" 00:01:02:03:04:06 { fixed-address 192.168.1.101; another-option "bla bla"; }
+# subclass "etherboot-pxe-hosts" 00:01:02:03:04:06 {
+# 	fixed-address 192.168.1.101;
+# 	another-option "bla bla";
+# 	if substring (option vendor-class-identifier, 0, 9) = "PXEClient" {
+# 		filename "/tftpboot/eepro100.lzpxe";
+# 	}
+# }
+#
+
+if substring (option vendor-class-identifier, 0, 9) = "PXEClient" {
+	filename "/tftpboot/eepro100.lzpxe"; 
+	} else if substring (option vendor-class-identifier, 0, 9) = "Etherboot" {
+		filename "/tftpboot/lts/vmlinuz-test.nbi"; 
+		option vendor-encapsulated-options 
+		3c:09:45:74:68:65:72:62:6f:6f:74:ff;
+	}
+}
diff --git a/dhcp3/dhcpd.etherboot-udhcp b/dhcp3/dhcpd.etherboot-udhcp
new file mode 100644
index 0000000..9a3e442
--- /dev/null
+++ b/dhcp3/dhcpd.etherboot-udhcp
@@ -0,0 +1,97 @@
+# This ISC dhcpd 3.x config snippet is inspired by initrd code in
+# contrib area of etherboot source (dhcpd.conf.etherboot.include).
+
+# Usage:
+#
+# include "/etc/local-COMMON/dhcp3/dhcpd.etherboot";
+# include "/etc/local-COMMON/dhcp3/dhcpd.etherboot-udhcp";
+# include "/etc/local/dhcpd.conf.etherboot-pcimap.include"; # file generated by mknbi-set
+#
+# (...common options...)
+#
+# subclass "etherboot-udhcp-hosts" 00:01:02:03:04:05;
+# subclass "etherboot-udhcp-hosts" 00:01:02:03:04:06 { fixed-address 192.168.1.101; another-option "bla bla"; }
+#
+
+class "etherboot-udhcp-hosts" {
+	match pick-first-value (option dhcp-client-identifier, hardware);
+}
+
+# Apply Etherboot options only for Etherboot clients
+#
+if substring ( option vendor-class-identifier, 0, 9 ) = "Etherboot" {
+
+	# We must specify this value for etherboot-magic, or Etherboot will
+	# ignore all other options.
+	#
+	option etherboot.magic E4:45:74:68:00:00;
+
+	# Bootfile name: derive from etherboot.kmod (calculated below)
+	# Use boot.nbi if no NIC_DEV_ID option present
+	# (i.e. if etherboot.kmod doesn't get set)
+	# Also pass filename back in filename field
+	#
+	option bootfile-name = pick-first-value (
+		concat (
+			"boot-",
+			config-option etherboot.kmod,
+			".nbi"
+		),
+		"boot.nbi"
+	) ;
+	filename = config-option bootfile-name;
+
+	# "Sensible" default values for some options
+
+	# Mount devfs (will probably be needed for a network-boot)
+	option etherboot.kernel-cmdline " devfs=mount";
+
+	# Info message (includes client IP address, MAC address, hardware ID string,
+	# server IP address and name of boot file)
+	option etherboot.motd-4 = concat (
+		"Using Etherboot to boot ",
+		binary-to-ascii ( 10, 8, ".", leased-address ),
+		" [",
+		binary-to-ascii ( 16, 8, ":", suffix ( hardware, 6 ) ),
+		"] [",
+		pick-first-value ( option etherboot.nic-dev-id, "unknown card" ),
+		"]", 0d:0a, "  from ",
+		binary-to-ascii ( 10, 8, ".", option dhcp-server-identifier ),
+		" with file ",
+		config-option tftp-server-name,
+		":",
+		config-option bootfile-name,
+		" [",
+		pick-first-value ( config-option etherboot.kmod, "unknown module" ),
+		"]", 0d:0a
+	);
+}
+
+# Some options should be set for both Etherboot and the udhcpc client
+#
+if (
+	( substring ( option vendor-class-identifier, 0, 9 ) = "Etherboot" )
+        or
+	( substring ( option vendor-class-identifier, 0, 5 ) = "udhcp" )
+) {
+
+	# TFTP server defaults to DHCP server and is specified in both
+	# next-server field and tftp-server-name option field
+	#
+	option tftp-server-name = binary-to-ascii ( 10, 8, ".", config-option dhcp-server-identifier );
+	server-name = config-option tftp-server-name;
+	next-server = config-option dhcp-server-identifier;
+
+	# Root path defaults to root of TFTP server
+	option root-path = concat ( config-option tftp-server-name, ":/" );
+
+	# A fallback hostname, generated from the IP address
+	option host-name = concat ( "client_", binary-to-ascii ( 10, 8, "_", leased-address ) );
+}
+
+# Force some items onto parameter request list for udhcp
+#
+if substring ( option vendor-class-identifier, 0, 5 ) = "udhcp" {
+	# Forcibly add root-path to list
+	option dhcp-parameter-request-list = concat ( option dhcp-parameter-request-list, 11 );
+}
diff --git a/dhcp3/dhcpd.fai b/dhcp3/dhcpd.fai
new file mode 100644
index 0000000..bf576bb
--- /dev/null
+++ b/dhcp3/dhcpd.fai
@@ -0,0 +1,4 @@
+# FAI (Fully Automated Install) options
+option fai-location	code 170 = text;
+option fai-action	code 171 = text;
+option fai-flags	code 172 = text;
diff --git a/dhcp3/dhcpd.grub b/dhcp3/dhcpd.grub
new file mode 100644
index 0000000..a8ac453
--- /dev/null
+++ b/dhcp3/dhcpd.grub
@@ -0,0 +1,36 @@
+# GRUB (GRand Unified Boot-loader) options
+
+# Usage:
+# Make a symlink from "/usr/share/grub-net/" to "/tftpboot/grub/", and
+# place a GRUB menu file at "/tftpboot/grub-hosts/menu.lst" (see
+# /usr/share/doc/grub-net/examples/menu.lst for an example).
+# Note that symlinks won't work if using chroot with tftp (which is much
+# recommended!) - copy pxegrub-all and nbgrub-all instead.
+
+# # Normal options first (including default filename, if any)
+# subnet 192.168.101.0 netmask 255.255.255.0 {
+# 	option broadcast-address 192.168.101.0;
+# 	option subnet-mask 255.255.255.0;
+#	range 192.168.101.101 192.168.101.199;
+# }
+#
+# include "/etc/local-common/dhcp3/dhcpd.grub";
+#
+# # Accepted hosts (syntax is "1:" + MAC address)
+# subclass "grub-hosts" 1:00:50:ba:8b:c2:7b;
+# subclass "grub-hosts" 1:00:01:02:0a:0b:0c { fixed-address 192.168.1.101; another-option "bla bla"; }
+
+option grub-configfile	code 150 = text;
+
+class "grub-hosts" {
+        match pick-first-value (option dhcp-client-identifier, hardware);
+
+	if substring (option vendor-class-identifier, 0, 9) = "PXEClient" {
+		filename	"grub/pxegrub-all";
+	} else if substring (option vendor-class-identifier, 0, 9) = "Etherboot" {
+		filename	"grub/nbgrub-all";
+		option vendor-encapsulated-options 3c:09:45:74:68:65:72:62:6f:6f:74:ff;
+	} else {
+		option grub-configfile "(nd)/grub-hosts/menu.lst";
+	}
+}
diff --git a/dhcp3/dhcpd.macintosh b/dhcp3/dhcpd.macintosh
new file mode 100644
index 0000000..01d56a2
--- /dev/null
+++ b/dhcp3/dhcpd.macintosh
@@ -0,0 +1,12 @@
+# Open Transport 2.5.1 and 2.5.2 fails with lease times larger than 1 hour
+class "Macintosh_a" {
+if (
+	( substring (hardware, 0, 3) = 00:05:02 )
+        or
+	( (hardware, 0, 3) = 00:61:61 )
+) {
+
+	default-lease-time	3599;
+	max-lease-time		3599;
+	min-lease-time		3599;
+}
diff --git a/dhcp3/dhcpd.pxe b/dhcp3/dhcpd.pxe
new file mode 100644
index 0000000..75f3489
--- /dev/null
+++ b/dhcp3/dhcpd.pxe
@@ -0,0 +1,31 @@
+# This ISC dhcpd 3.x config snippet is inspired by the following:
+#   http://www.bpbatch.org/docs/linux.html
+
+# TODO: Otpmize to different releases of PXE.
+# According to http://cui.unige.ch/info/pc/remote-boot/howto-3.html
+# "PXE 2.0 bootroms can only receive option 128-135".
+
+# Definition of PXE-specific options
+# Code 1: Multicast IP address of bootfile
+# Code 2: UDP port that client should monitor for MTFTP responses
+# Code 3: UDP port that MTFTP servers are using to listen
+#         for MTFTP requests
+# Code 4: Number of secondes a client must listen for activity before
+#         trying to start a new MTFTP transfer
+# Code 5: Number of secondes a client must listen before trying to
+#         restart a MTFTP transfer
+option space PXE;
+option PXE.mtftp-ip		code 1 = ip-address;
+option PXE.mtftp-cport		code 2 = unsigned integer 16;
+option PXE.mtftp-sport		code 3 = unsigned integer 16;
+option PXE.mtftp-tmout		code 4 = unsigned integer 8;
+option PXE.mtftp-delay		code 5 = unsigned integer 8;
+
+# Sample host config
+#host pxetest1 {
+#	hardware	ethernet 00:01:02:03:04:05;
+#	fixed-address	192.168.1.101;
+#	next-server	192.168.1.2;
+#	filename	"pxelinux.0";
+#	include "/etc/local-COMMON/dhcp3/dhcpd.pxe.host";
+#}
diff --git a/dhcp3/dhcpd.pxe.host b/dhcp3/dhcpd.pxe.host
new file mode 100644
index 0000000..05c2399
--- /dev/null
+++ b/dhcp3/dhcpd.pxe.host
@@ -0,0 +1,13 @@
+# Host-specific PXE options
+class "pxe" {
+	match if substring (option vendor-class-identifier, 0, 9) = "PXEClient";
+
+	# Keep identifier
+	option vendor-class-identifier "PXEClient";
+
+	# At least one of the vendor-specific option must be set. We set
+	# the MCAST IP address to 0.0.0.0 to tell the bootrom to still use
+	# TFTP (address 0.0.0.0 is considered as "no address")
+	option PXE.mtftp-ip 0.0.0.0;
+	vendor-option-space PXE;
+}
diff --git a/dhcp3/dhcpd.pxe.host-mcast b/dhcp3/dhcpd.pxe.host-mcast
new file mode 100644
index 0000000..158e237
--- /dev/null
+++ b/dhcp3/dhcpd.pxe.host-mcast
@@ -0,0 +1,12 @@
+# Host-specific PXE options
+class "pxeclients" {
+	match if substring (option vendor-class-identifier, 0, 9) = "PXEClient";
+
+	# Keep identifier
+	option vendor-class-identifier "PXEClient";
+
+	option PXE.mtftp-ip	224.1.5.1;
+	option PXE.mtftp-cport	1758;
+	option PXE.mtftp-sport	1759;
+	vendor-option-space PXE;
+}
diff --git a/dhcp3/dhcpd.pxelinux b/dhcp3/dhcpd.pxelinux
new file mode 100644
index 0000000..c8af5a8
--- /dev/null
+++ b/dhcp3/dhcpd.pxelinux
@@ -0,0 +1,9 @@
+# This ISC dhcpd 3.x config snippet is inspired by pxelinux.doc,
+# part of the syslinux software package.
+# Hint: Other goodies here: http://syslinux.zytor.com/hardware.php
+
+option space pxelinux;
+option pxelinux.magic		code 208 = string;
+option pxelinux.configfile	code 209 = text;
+option pxelinux.pathprefix	code 210 = text;
+option pxelinux.reboottime	code 211 = unsigned integer 32;
diff --git a/dhcp3/dhcpd.pxelinux.host b/dhcp3/dhcpd.pxelinux.host
new file mode 100644
index 0000000..33d0c19
--- /dev/null
+++ b/dhcp3/dhcpd.pxelinux.host
@@ -0,0 +1,18 @@
+class "pxeclient" {
+	match if substring (option vendor-class-identifier, 0, 9) = "PXEClient";
+
+	# Always include the following lines for all PXELINUX clients
+	site-option-space		"pxelinux";
+	option pxelinux.magic		f1:00:74:7e;
+	if exists dhcp-parameter-request-list {
+		# Always send the PXELINUX options
+		append dhcp-parameter-request-list 208, 209, 210, 211;
+	}
+
+	# Allow config based on MAC address
+	option pxelinux.configfile = concat("/pxelinux.cfg/", binary-to-ascii(16, 8, ":", hardware));
+
+	# Load pxelinux from subfolder (make that a symlink to the actual location of syslinux binaries)
+	filename			"/pxelinux/pxelinux.0";
+	option pxelinux.pathprefix	"/";
+}
diff --git a/dhcp3/dhcpd.wpad b/dhcp3/dhcpd.wpad
new file mode 100644
index 0000000..33bae60
--- /dev/null
+++ b/dhcp3/dhcpd.wpad
@@ -0,0 +1,10 @@
+# Web Proxy Auto-Discovery Protocol (described in RFC 3040, used in
+# Microsoft Internet Explorer 5.0 and later and maybe Mozilla).
+option wpad-url			code 252 = text;
+
+# Sample domain config
+
+# Beware that Microsoft Internet Explorer resolves hostname ahead,
+# (A record if CNAME record provided, and raw IP if A record provided),
+# so use the default web host if serving name-based virtual hosts.
+#option auto-proxy-config	"http://wpad.example.net/wpad.pac";