Application layer BGP DHCP DNS FTP HTTP IMAP LDAP MGCP NNTP NTP POP ONC/RPC RTP RTSP RIP SIP SMTP SNMP SSH Telnet TLS/SSL XMPP more... Transport layer TCP UDP DCCP SCTP RSVP more... Internet layer IP IPv4 IPv6 ICMP ICMPv6 ECN IGMP IPsec more... Link layer ARP NDP OSPF Tunnels L2TP PPP MAC Ethernet DSL ISDN FDDI more... The following tables list the available DHCP options, as stated in RFC2132.[14] RFC1497 vendor extensions[14]:Section 3 Code Name Length Notes 0 Pad[14]:Section 3.1 0 octets Can be used to pad other options so that they are aligned to the word boundary; is not followed by length byte 1 Subnet Mask[14]:Section 3.3 4 octets Must be sent after the router option (option 3) if both are included 2 Time Offset[14]:Section 3.4 4 octets 3 Router multiples of 4 octets Available routers, should be listed in order of preference 4 Time Server multiples of 4 octets Available time servers to synchronise with, should be listed in order of preference 5 Name Server multiples of 4 octets Available IEN 116 name servers, should be listed in order of preference 6 Domain Name Server multiples of 4 octets Available DNS servers, should be listed in order of preference 7 Log Server multiples of 4 octets Available log servers, should be listed in order of preference. 8 Cookie Server multiples of 4 octets "Cookie" in this case means "fortune cookie" or "quote of the day," a pithy or humorous anecdote often sent as part of a logon process on large computers; it has nothing to do with cookies sent by websites. 9 LPR Server multiples of 4 octets 10 Impress Server multiples of 4 octets 11 Resource Location Server multiples of 4 octets 12 Host Name minimum of 1 octet 13 Boot File Size 2 octets Length of the boot image in 4KiB blocks 14 Merit Dump File minimum of 1 octet Path where crash dumps should be stored 15 Domain Name minimum of 1 octet 16 Swap Server 4 octets 17 Root Path minimum of 1 octet 18 Extensions Path minimum of 1 octet 255 End 0 octets Used to mark the end of the vendor option field IP Layer Parameters per Host[14]:Section 4 Code Name Length Notes 19 IP Forwarding Enable/Disable 1 octet 20 Non-Local Source Routing Enable/Disable 1 octet 21 Policy Filter multiples of 8 octets 22 Maximum Datagram Reassembly Size 2 octets 23 Default IP Time-to-live 1 octet 24 Path MTU Aging Timeout 4 octets 25 Path MTU Plateau Table multiples of 2 octets IP Layer Parameters per Interface[14]:Section 5 Code Name Length Notes 26 Interface MTU 2 octets 27 All Subnets are Local 1 octet 28 Broadcast Address 4 octets 29 Perform Mask Discovery 1 octet 30 Mask Supplier 1 octet 31 Perform Router Discovery 1 octet 32 Router Solicitation Address 4 octets 33 Static Route multiples of 8 octets A list of destination/router pairs Link Layer Parameters per Interface[14]:Section 6 Code Name Length Notes 34 Trailer Encapsulation Option 1 octet 35 ARP Cache Timeout 4 octets 36 Ethernet Encapsulation 1 octet TCP Parameters[14]:Section 7 Code Name Length Notes 37 TCP Default TTL 1 octet 38 TCP Keepalive Interval 4 octets 39 TCP Keepalive Garbage 1 octet Application and Service Parameters[14]:Section 8 Code Name Length Notes 40 Network Information Service Domain minimum of 1 octet 41 Network Information Servers multiples of 4 octets 42 Network Time Protocol Servers multiples of 4 octets 43 Vendor Specific Information minimum of 1 octets 44 NetBIOS over TCP/IP Name Server multiples of 4 octets 45 NetBIOS over TCP/IP Datagram Distribution Server multiples of 4 octets 46 NetBIOS over TCP/IP Node Type 1 octet 47 NetBIOS over TCP/IP Scope minimum of 1 octet 48 X Window System Font Server multiples of 4 octets 49 X Window System Display Manager multiples of 4 octets 64 Network Information Service+ Domain minimum of 1 octet 65 Network Information Service+ Servers multiples of 4 octets 68 Mobile IP Home Agent multiples of 4 octets 69 Simple Mail Transport Protocol (SMTP) Server multiples of 4 octets 70 Post Office Protocol (POP3) Server multiples of 4 octets 71 Network News Transport Protocol (NNTP) Server multiples of 4 octets 72 Default World Wide Web (WWW) Server multiples of 4 octets 73 Default Finger Server multiples of 4 octets 74 Default Internet Relay Chat (IRC) Server multiples of 4 octets 75 StreetTalk Server multiples of 4 octets 76 StreetTalk Directory Assistance (STDA) Server multiples of 4 octets DHCP Extensions[14]:Section 9 Code Name Length Notes 50 Requested IP address 4 octets 51 IP address Lease Time 4 octets 52 Option Overload 1 octet 53 DHCP Message Type 1 octet 54 Server Identifier 4 octets 55 Parameter Request List minimum of 1 octet 56 Message minimum of 1 octet 57 Maximum DHCP Message Size 2 octets 58 Renewal (T1) Time Value 4 octets 59 Rebinding (T2) Time Value 4 octets 60 Vendor class identifier minimum of 1 octet 61 Client-identifier minimum of 2 octets 66 TFTP server name minimum of 1 octet 67 Bootfile name minimum of 1 octet