RIP, Routing Information Protocol

Description Glossary RFCs Publications Obsolete RFCs


Protocol suite:Novell NetWare.
Protocol type:Interior gateway protocol, distance vector.
Multicast addresses:
MIME subtype:
Working groups:

RIP transmits routing table information to other servers and routers on the network. A RIP request packet is to find routing information. A RIP response packet contains the routing information.

RFC 1582, page 17:

Netware RIP and IP RIP share a common heritage, in that they are both based on XNS RIP, but there is some divergence, mostly at the packet format level to reflect the differing addressing schemes.

The triggered update mechanism can be applied to Netware RIP.

RFC 1582, page 1.

Routing information is sent on the WAN when the routing database is modified by new routing information received from another interface. When this happens a (triggered) update is sent to a list of destinations on other WAN interfaces. Because routing protocols are datagram based they are not guaranteed to be received by the peer router on the WAN. An acknowledgement and retransmission mechanism is provided to ensure that routing updates are received.

RFC 2091, page 3.

Periodic broadcasting by Bellman-Ford (distance vector) algorithm information broadcasting protocols IP RIP, IP RIP V2 or Netware RIP and SAP generally prevents WAN circuits from being closed. Even on fixed point-to-point links the overhead of periodic transmission of RIP - and even more so SAP broadcasts - can seriously interrupt normal data transfer simply through the quantity of information which hits the line every 30 or 60 seconds.

To overcome these limitations, this specification modifies the distance vector protocols so as to send information on the WAN only when there has been an update to the routing database OR a change in the reachability of a next hop router is indicated by the task which manages connections on the WAN.

Because datagrams are not guaranteed to get through on all WAN media, an acknowledgement and retransmission system is required to provide reliability.

The protocols run unmodified on Local Area Networks (LANs) and so interoperate transparently with implementations adhering to the original specifications.

MAC header IPX header RIP packet

Packet format:

0001020304050607 0809101112131415
Packet Request/Response Type
Network Address
Network Hops

Packet Request/Response Type. 16 bits.

1Standard NetWare RIP Request. A request for the responding system to send all or part of its routing table.
2 Standard NetWare RIP Response. A message containing all or part of the sender's routing table. This message may be sent in response to a request, or it may be an unsolicited routing update generated by the sender.
6 Triggered request. A request for the responding system to send all of its routing database. RFC 1582
7 Triggered response. A message containing all of the sender's routing database, excluding those entries learned from the interface to which the routing information is being sent. RFC 1582
8 Triggered acknowledgement. A message sent in response to every triggered response packet received. RFC 1582
9 Operations update request. RFC 2091
10 Update response. RFC 2091
11Update Acknowledge. RFC 2091

Network Address. 32 bits.
For request packets, the network address being searched.

Network Hops. 16 bits.
For response packets, an incremental hop is counted each time a packet passes through a router to reach a certain network. For request packets, this field is set to 0xFFFF.

Time. 16 bits.
For response packets, the time in ticks 1/18 of a second; this is to count the total number of ticks it takes to reach a network. For request packets, this field is set to 0xFFFF.

1...n, variable.
In the response packet, the last three fields can be repeated up to 50 times for each network route.


IPX, Internet Packet Exchange.
Novell NetWare connectionless network protocol.

SAP, Service Advertising Protocol.
Novell NetWare protocol which is used for service providers to advertise their services on the network.


[RFC 1582] Extensions to RIP to Support Demand Circuits.

[RFC 2091] Triggered Extensions to RIP to Support Demand Circuits.


Obsolete RFCs:

Description Glossary RFCs Publications Obsolete RFCs