Provided by:
dhcp3-common_3.1.3-2ubuntu6_i386 
dhcp-eval - ISC DHCP
Internet Systems Consortium DHCP
:
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"
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)