Internet Assigned Numbers Authority

Internet Protocol Version 4 (IPv4) Parameters

Last Updated
2018-05-03
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Registries included below

IP Option Numbers

Registration Procedure(s)
Not defined
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 referred to by this value.
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]

IPv4 Router Alert Option Values

Registration Procedure(s)
IETF Review
Reference
[RFC5350]
Available Formats

CSV
Value Description Reference
0 Router shall examine packet [RFC2113]
1-32 Aggregated Reservation Nesting Level [RFC3175]
33-64 QoS NSLP Aggregation Levels 0-31 [RFC5974]
65 NSIS NATFW NSLP [RFC5973]
66-65502 Unassigned
65503-65534 Reserved for experimental use [RFC5350]
65535 Reserved [RFC5350]

IP Time to Live Parameter

Registration Procedure(s)
Not defined
Note
The current recommended default time to live (TTL) for the Internet
Protocol (IP) is 64 [RFC791][RFC1122].

IP TOS Parameters

Registration Procedure(s)
Registrations no longer accepted
Note
This registry was deprecated following the publication of [RFC2474].

Type-of-Service Values

Registration Procedure(s)
Registrations no longer accepted
Note
This registry was deprecated following the publication of [RFC2474].

Contact Information

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.