IFMP, Ipsilon Flow Management Protocol

Description Glossary RFCs Publications Obsolete RFCs


Protocol suite: TCP/IP.
Protocol type:Transport layer protocol.
Multicast addresses:
IP protocol:101.
MIME subtype:
Working groups:

Propietary Ipsilon protocol.

RFC 1953:

IFMP is a protocol for allowing a node to instruct an adjacent node to attach a layer 2 label to a specified IP flow. The label allows more efficient access to cached routing information for that flow. The label can also enable a node to switch further packets belonging to the specified flow at layer 2 rather than forwarding them at layer 3.

IFMP consists of two sub protocols, the IFMP Adjacency Protocol and the IFMP Redirection Protocol.

The IFMP Adjacency Protocol allows a host or router to discover the identity of a peer at the other end of a link. It is also used to synchronize state across the link, to detect when the peer at the other end of the link changes, and to exchange a list of IP addresses assigned to the link. All IFMP messages belonging to the Adjacency Protocol must be encapsulated within an IPv4 packet. The destination IP address is always set to the limited broadcast address (

The IFMP Redirection Protocol is used to direct a flow. The sender encapsulates these messages in an IPv4 packet with the destination IP address set to the unicast IP address of the peer at the other end of the link. The IP address of the peer is obtained through previous use of the IFMP Adjacency Protocol.

MAC header IP IFMP header Data :::

IFMP header:

0001020304050607 0809101112131415 1617181920212223 2425262728293031
Version IHL TOS Total length
Identification Flags Fragment offset
TTL Protocol Header checksum
Source IP address
Destination IP address
IFMP message :::

TTL, Time to Live. 8 bits.
A timer field used to track the lifetime of the datagram. When the TTL field is decremented down to zero, the datagram is discarded. Always set to 1 by the sender.

Protocol. 8 bits.
This field specifies the IFMP protocol. Always set to 101.



[RFC 1953] Ipsilon Flow Management Protocol Specification for IPv4 Version 1.0.

[RFC 1954] Transmission of Flow Labelled IPv4 on ATM Data Links Ipsilon Version 1.0.


Obsolete RFCs:

Description Glossary RFCs Publications Obsolete RFCs