MZAP, Multicast-Scope Zone Announcement Protocol

Description Glossary RFCs Publications Obsolete RFCs


Protocol suite: TCP/IP.
Protocol type:Application layer protocol.
Multicast addresses:
Ports:2106 (UDP) server.
MIME subtype:
Working groups: mboned, MBONE Deployment.

MAC header IP header UDP header MZAP header Data :::

MZAP header:

0001020304050607 0809101112131415 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31
Version B Type Address family Namecount
Message Origin :::
Zone ID address :::
Zone start address :::
Zone end address :::
Encoded zone name[] :::

Version. 8 bits.
MZAP version number. Should be cleared to 0.

B, Big scope. 1 bit.

0The addresses in the scoped range are not subdividable, and that address allocators may utilize the entire range.
1Address allocators should not use the entire range, but should learn an appropriate sub-range via another mechanism.

Type. 7 bits.
Packet type.

0 ZAM, Zone Announcement Message. RFC 2776
1ZLE, Zone Limit Exceeded. RFC 2776
2ZCM, Zone Convexity Message. RFC 2776
3 NIM, Not-Inside Message. RFC 2776

Address family. 8 bits.
The IANA-assigned address family number identifying the address family for all addresses in the packet.


Namecount. 8 bits.
The number of encoded zone name blocks in this packet. May be set to zero.

Message Origin. 32 bits (IPv4) or 128 bits (IPv6).
IP address of the interface that originated the message.

Zone ID address. 32 bits (IPv4) or 128 bits (IPv6).
This gives the lowest IP address of a boundary router that has been observed in the zone originating the message. Together with Zone start address and Zone end address, it forms a unique ID for the zone. Note that this ID is usually different from the ID of the Local Scope zone in which the origin resides.

Zone start address. 32 bits (IPv4) or 128 bits (IPv6).
The start IP address for the scope zone boundary.

Zone end address. 32 bits (IPv4) or 128 bits (IPv6).
The ending IP address for the scope zone boundary.

Encoded zone name[]. Variable length.
A list of Encoded zone name elements.

padding. Variable length, 0 to 3 bytes.
Used to pad the packet to a multiple of 32 bits.

Encoded zone name: Variable length.

D reserved
Tag length
Language tag :::
Name length
Zone name :::

D, default Language. 1 bit.
If set, indicates a preference that the name in the following language should be used if no name is available in a desired language.

reserved. 7 bits.
Should be cleared to zero on transmission and ignored on reception.

Tag length. 8 bits.
Size of the Language tag in bytes.

Language tag. Variable length, 0 to 255 bytes.
The language of the zone name.

Name length. 8 bits.
Size of the Zone name in bytes.

Zone name. Variable length, 0 to 255 bytes.
An ISO 10646 character string in UTF-8 encoding indicating the name given to the scope zone (eg: "ISI-West Site"). It should be relatively short, and white space SHOULD be stripped from the beginning and end of each name before encoding, to avoid accidental conflicts.



[RFC 2776] Multicast-Scope Zone Announcement Protocol (MZAP).


Obsolete RFCs:

Description Glossary RFCs Publications Obsolete RFCs