Provided by:
isc-dhcp-common_4.1.ESV-R4-0ubuntu5_i386 
:
if, else, elsif (option ) :
if option dhcp-user-class = "accounting" {
max-lease-time 17600;
option domain-name "accounting.example.org";
option domain-name-servers ns1.accounting.example.org,
ns2.accounting.example.org;
} elsif option dhcp-user-class = "sales" {
max-lease-time 17600;
option domain-name "sales.example.org";
option domain-name-servers ns1.sales.example.org,
ns2.sales.example.org;
} elsif option dhcp-user-class = "engineering" {
max-lease-time 17600;
option domain-name "engineering.example.org";
option domain-name-servers ns1.engineering.example.org,
ns2.engineering.example.org;
} else {
max-lease-time 600;
option domain-name "misc.example.org";
option domain-name-servers ns1.misc.example.org,
ns2.misc.example.org;
}
:
# example.org DNS
# example.org DNS
# example.org DNS
if not option domain-name = "example.org" {
prepend domain-name-servers 127.0.0.1;
}
if elsif if elsif else elsif elsif elsif else if elsif else else
DHCP
data-expression-1 = data-expression-2
= 2
boolean-expression-1 and boolean-expression-2
and
boolean-expression-1 or boolean-expression-2
or
not boolean-expression
not boolean-expression boolean-expression boolean-expression
exists option-name
exists DCHP
known
known
static
static
substring (data-expr, offset, length)
substring offset length offset length data-expr, offset, length
offset 0 length offset offset
suffix (data-expr, length)
suffix data-expr length length data-expr length suffix (: length )
option option-name
option
config-option option-name
config-option DHCP
hardware
hardware RFC2131 hlen (1) (6) FDDI (8) IETF RFC2131 (ISC DHCP
doc/ )
packet (offset, length)
packet offset length substring
string
ASCII ('\') C : '\t' '\r' '\n' '\b' 8 '\nnn' nnn 0 0377 8 16
'\xnn' nn 0 0xff 16
colon-separated hexadecimal list
16
concat (data-expr1, ..., data-exprN)
reverse (numeric-expr1, data-expr2)
2 4 12 reverse 12 4 4 4
leased-address
IP IP
binary-to-ascii (numeric-expr1, numeric-expr2, data-expr1, data-expr2)
data-expr2 data-expr2 1 data-expr1 numeric-expr1 (2 16) numeric-
expr2 8, 16, 32
3 IP PTR
concat (binary-to-ascii (10, 8, ".",
reverse (1, leased-address)),
".in-addr.arpa.");
encode-int (numeric-expr, width)
()
pick-first-value (data-expr1 [ ... exprn ] )
pick-first-value
host-decl-name
host-decl-name
32 32
extract-int (data-expr, width)
extract-int 8, 16, 32
lease-time
number
0
client-state
DHCP :
+o Booting - DHCP INIT IP DHCPDISCOVER
+o Reboot - DHCP INIT-REBOOT IP DHCPREQUEST BOUND
+o Select - DHCP SELECTING 1 DHCPOFFER DHCPOFFER SELECTING
+o Request - DHCP REQUESTING 1 DHCPOFFER DHCPREQUEST
+o Bound - DHCP BOUND IP
+o Renew - DHCP RENEWING IP DHCPREQUEST
+o Rebind - DHCP REBINDING IP DHCPREQUEST
:
priority (fatal, error, info, debug )
log (priority, data-expr)
concat
: DNS
DHCP RFC 2136 RFC 2136 DNS DHCP
TSIG DNSSEC DHCP DNS DNS IP TSIG DNSSEC DHCP
DNS (DDNS) dns-update dns-update 4 4 (RR) RR RR ttl dhcpd.conf dns-
update
dns-update 1 A RR 2 DHCP host-name "ssd.example.net" 3 32 "."
ASCII 4 TTL ( DNS TTL )
dns-update 2 PTR RR PTR A RR ".in-addr.arpa"
dhcpd.conf(5), dhcpd.leases(5), dhclient.conf(5), dhcp-eval(5),
dhcpd(8), dhclient(8), RFC2132, RFC2131
Internet Systems Consortium DHCP Distribution Vixie Labs Ted Lemon
Internet Systems Consortium Internet Systems Consortium
https://www.isc.org
dhcp-eval(5)