Internet Protocol Control Protocol
Encyclopedia
In computer networking, Internet Protocol Control Protocol (IPCP) is a network control protocol
for establishing and configuring Internet Protocol
over a Point-to-Point Protocol
link. IPCP uses the same packet exchange mechanism as the Link Control Protocol
. IPCP packets may not be exchanged until PPP has reached the Network-Layer Protocol phase, and any IPCP packets received before this phase is reached should be silently discarded.
IPCP header:
Code.
8 bits.
Specifies the function to be performed.
Identifier.
8 bits.
Used to match requests and replies.
Length.
16 bits.
Size of the packet including the header.
Data.
Variable length.
Zero or more bytes of data as indicated by the Length.
This field may contain one or more Options.
----
, with a separate set of Options.
IPCP Configuration Options:
Option.
8 bits.
Length.
8 bits.
Data.
Variable length.
Network Control Protocol
A Network Control Protocol is a protocol that runs atop the Point-to-Point Protocol and that is used to negotiate options for a network layer protocol running atop PPP...
for establishing and configuring Internet Protocol
Internet Protocol
The Internet Protocol is the principal communications protocol used for relaying datagrams across an internetwork using the Internet Protocol Suite...
over a Point-to-Point Protocol
Point-to-Point Protocol
In networking, the Point-to-Point Protocol is a data link protocol commonly used in establishing a direct connection between two networking nodes...
link. IPCP uses the same packet exchange mechanism as the Link Control Protocol
Link Control Protocol
In computing, the Link Control Protocol forms part of the Point-to-Point Protocol. In setting up PPP communications, both the sending and receiving devices send out LCP packets to determine the standards of the ensuing data transmission...
. IPCP packets may not be exchanged until PPP has reached the Network-Layer Protocol phase, and any IPCP packets received before this phase is reached should be silently discarded.
IP Frame
After the configuration is done, the link is able to carry IP data as a payload of the PPP frame. This code indicates that IP data is being carried.| PPP header | IPCP header | Data ::: |
IPCP header:
| 00 | 01 | 02 | 03 | 04 | 05 | 06 | 07 | 08 | 09 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Code | Identifier | Length | |||||||||||||||||||||||||||||
| Data ::: | |||||||||||||||||||||||||||||||
Code.
8 bits.
Specifies the function to be performed.
| Code | Description | References |
|---|---|---|
| 0 | Vendor Specific. | RFC 2153 |
| 1 | Configure-Request. | |
| 2 | Configure-Ack. | |
| 3 | Configure-Nak. | |
| 4 | Configure-Reject. | |
| 5 | Terminate-Request. | |
| 6 | Terminate-Ack. | |
| 7 | Code-Reject. |
Identifier.
8 bits.
Used to match requests and replies.
Length.
16 bits.
Size of the packet including the header.
Data.
Variable length.
Zero or more bytes of data as indicated by the Length.
This field may contain one or more Options.
----
Configuration Options
IPCP Configuration Options allow negotiatiation of desirable Internet Protocol parameters. IPCP uses the same Configuration Option format defined for LCP Link Control ProtocolLink Control Protocol
In computing, the Link Control Protocol forms part of the Point-to-Point Protocol. In setting up PPP communications, both the sending and receiving devices send out LCP packets to determine the standards of the ensuing data transmission...
, with a separate set of Options.
IPCP Configuration Options:
| 00 | 01 | 02 | 03 | 04 | 05 | 06 | 07 | 08 | 09 | 10 | 11 | 12 | 13 | 14 | 15 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Option | Length | ||||||||||||||
| Data ::: | |||||||||||||||
Option.
8 bits.
| Option | Length | Description | References |
|---|---|---|---|
| 1 | IP-Addresses (deprecated). | RFC 1332 | |
| 2 | >= 14 | IP-Compression-Protocol. | RFC 1332, RFC 3241, RFC 3544 |
| 3 | 6 | IP-Address. | RFC 1332 |
| 4 | 6 | Mobile-IPv4. | RFC 2290 |
| 129 | 6 | Primary DNS Server Address. | RFC 1877 |
| 130 | 6 | Primary NBNS Server Address. | RFC 1877 |
| 131 | 6 | Secondary DNS Server Address. | RFC 1877 |
| 132 | 6 | Secondary NBNS Server Address. | RFC 1877 |
Length.
8 bits.
Data.
Variable length.
IP-Compression-Protocol
| Type | Length | IP-Compression-Protocol | Data |
|---|---|---|---|
| 1 byte | 1 byte | 2 bytes | variable |