IP OPTION NUMBERS

Last Updated
2013-05-28
Note
The Internet Protocol (IP) has provision for optional header fields
identified by an option type field.  Options 0 and 1 are exactly one
octet which is their type field.  All other options have their one
octet type field, followed by a one octet length field, followed by
length-2 octets of option data.  The option type field is sub-divided
into a one bit copied flag, a two bit class field, and a five bit
option number.  These taken together form an eight bit value for the
option type field.  IP options are commonly refered to by this value.
Available Formats

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HTML

Plain text

Registries included below

Available Formats

CSV
Copy Class Number Value Name Reference
0 0 0 0
EOOL   - End of Options List
[RFC791][Jon_Postel]
0 0 1 1
NOP    - No Operation
[RFC791][Jon_Postel]
1 0 2 130
SEC    - Security
[RFC1108]
1 0 3 131
LSR    - Loose Source Route
[RFC791][Jon_Postel]
0 2 4 68
TS     - Time Stamp
[RFC791][Jon_Postel]
1 0 5 133
E-SEC  - Extended Security
[RFC1108]
1 0 6 134
CIPSO  - Commercial Security
[draft-ietf-cipso-ipsecurity-01]
0 0 7 7
RR     - Record Route
[RFC791][Jon_Postel]
1 0 8 136
SID    - Stream ID
[RFC791][Jon_Postel][RFC6814][1]
1 0 9 137
SSR    - Strict Source Route
[RFC791][Jon_Postel]
0 0 10 10
ZSU    - Experimental Measurement
[ZSu]
0 0 11 11
MTUP   - MTU Probe
[RFC1063][RFC1191][1]
0 0 12 12
MTUR   - MTU Reply
[RFC1063][RFC1191][1]
1 2 13 205
FINN   - Experimental Flow Control
[Greg_Finn]
1 0 14 142
VISA   - Experimental Access Control
[Deborah_Estrin][RFC6814][1]
0 0 15 15
ENCODE - ???
[VerSteeg][RFC6814][1]
1 0 16 144
IMITD  - IMI Traffic Descriptor
[Lee]
1 0 17 145
EIP    - Extended Internet Protocol
[RFC1385][RFC6814][1]
0 2 18 82
TR     - Traceroute
[RFC1393][RFC6814][1]
1 0 19 147
ADDEXT - Address Extension
[Ullmann IPv7][RFC6814][1]
1 0 20 148
RTRALT - Router Alert
[RFC2113]
1 0 21 149
SDB    - Selective Directed Broadcast
[Charles_Bud_Graff][RFC6814][1]
1 0 22 150
       - Unassigned (Released 18 October 2005)
1 0 23 151
DPS    - Dynamic Packet State
[Andy_Malis][RFC6814][1]
1 0 24 152
UMP    - Upstream Multicast Pkt.
[Dino_Farinacci][RFC6814][1]
0 0 25 25
QS     - Quick-Start
[RFC4782]
0 0 30 30
EXP    - RFC3692-style Experiment [2]
[RFC4727]
0 2 30 94
EXP    - RFC3692-style Experiment [2]
[RFC4727]
1 0 30 158
EXP    - RFC3692-style Experiment [2]
[RFC4727]
1 2 30 222
EXP    - RFC3692-style Experiment [2]
[RFC4727]

IP TIME TO LIVE PARAMETER

Note
The current recommended default time to live (TTL) for the Internet
Protocol (IP) is 64 [RFC791], [RFC1122].

IP TOS PARAMETERS

Description
This documents the default Type-of-Service values that are currently
recommended for the most important Internet protocols.
Available Formats

CSV
TOS Value Description Reference
0000 Default [Obsoleted by RFC2474]
0001 Minimize Monetary Cost [Obsoleted by RFC2474]
0010 Maximize Reliability [Obsoleted by RFC2474]
0100 Maximize Throughput [Obsoleted by RFC2474]
1000 Minimize Delay [Obsoleted by RFC2474]
1111 Maximize Security [Obsoleted by RFC2474]

Type-of-Service Values

Note
The TOS value is used to indicate "better".  Only one TOS value or
property can be requested in any one IP datagram.

Generally, protocols which are involved in direct interaction with a
human should select low delay, while data transfers which may involve
large blocks of data are need high throughput.  Finally, high reliability
is most important for datagram-based Internet management functions.

Application protocols not included in these tables should be able to
make appropriate choice of low delay (8 decimal, 1000 binary) or high
throughput (4 decimal, 0100 binary).

The following are recommended values for TOS.

An application may (at the request of the user) substitute
0001 (minimize monetary cost) for any of the below values.
Available Formats

CSV
Protocol TOS Value Description
TELNET [3] 1000 (minimize delay)
FTP
  Control 1000 (minimize delay)
  Data [4] 0100 (maximize throughput)
TFTP 1000 (minimize delay)
SMTP [5]
  Command phase 1000 (minimize delay)
  DATA phase 0100 (maximize throughput)
Domain Name Service
  UDP Query 1000 (minimize delay)
  TCP Query 0000
  Zone Transfer 0100 (maximize throughput)
NNTP 0001 (minimize monetary cost)
ICMP
  Errors 0000
  Requests 0000 [6]
  Responses <same as request> [6]
Any IGP 0010 (maximize reliability)
EGP 0000
SNMP 0010 (maximize reliability)
BOOTP 0000

People

ID Name Contact URI Last Updated
[Andy_Malis] Andy Malis mailto:agmalis&gmail.com 2013-05-28
[Charles_Bud_Graff] Charles "Bud" Graff mailto:bud&fotlan.army.mil 1995-03
[Deborah_Estrin] Deborah Estrin mailto:Estrin&usc.edu 1994-10
[Dino_Farinacci] Dino Farinacci mailto:dino&cisco.com 1999-05
[Greg_Finn] Greg Finn mailto:Finn&isi.edu 1994-10
[Jon_Postel] Jon Postel mailto:postel&isi.edu 1994-10

Footnotes

[1]
obsoleted IP Option Number
[2]
It is only appropriate to use these values
in explicitly-configured experiments; they MUST NOT be shipped as
defaults in implementations.  See RFC 3692 for details.
[3]
Includes all interactive user protocols (e.g., rlogin).
[4]
Includes all bulk data transfer protocols (e.g., rcp).
[5]
If the implementation does not support changing the TOS
during the lifetime of the connection, then the
recommended TOS on opening the connection is the default
TOS (0000).
[6]
Although ICMP request messages are normally sent with
the default TOS, there are sometimes good reasons why they
would be sent with some other TOS value.  An ICMP
response always uses the same TOS value as was used in the
corresponding ICMP request message.