Routing Information Protocol (RIP) is one of the oldest distance-vector routing protocols which employ the hop count as a routing metric. RIP prevents routing loops by implementing a limit on the number of hops allowed in a path from the source to a destination. The maximum number of hops in RIP is 15, which means that any network that is 16 hops away or more is considered unreachable.
Versions of RIP:
RIPv1:
- Classful routing protocol.
- Does not support CIDR (Classless Inter-Domain Routing) or VLSM (Variable Length Subnet Mask).
- Updates are broadcasted.
- No authentication feature.
RIPv2:
- Classless routing protocol.
- Supports CIDR and VLSM.
- Uses multicast to send updates to 224.0.0.9.
- Supports simple password authentication.
RIP Features and Characteristics:
- Routing UpdatesRIP routers transmit their entire routing table to their immediate neighbors every 30 seconds.
- MetricThe only metric used by RIP is hop count. A hop count of 16 is considered an infinite distance (i.e., the network is unreachable).
- TimersRIP uses various timers to regulate its performance:
- Update Timer30 seconds (time interval for regular routing updates).
- Invalid Timer180 seconds (time after which a route is considered invalid if no update is received).
- Hold Down Timer180 seconds (time during which routing information is suppressed or held down).
- Flush Timer240 seconds (time after which a route is removed from the routing table).
- Split HorizonThis is a technique to prevent loops in RIP by ensuring that route information is not sent back in the direction from which it was received.
- Route PoisoningWhen a route becomes invalid, RIP advertises it with a metric of 16 to inform other routers about the unreachable route.
- Triggered UpdatesWhen a router detects a network topology change, it sends an update immediately rather than waiting for the next regular update.
Limitations of RIP:
- ScaleDue to the maximum hop count of 15, RIP is not suitable for large networks.
- ConvergenceRIP can be slow to converge (adapt to network changes), especially in larger networks. This can lead to routing loops during the period of convergence.
- TrafficRIP’s periodic full-table updates can be inefficient, especially on networks with low bandwidth links.
Despite its limitations, RIP’s simplicity made it popular in the early days of networking. However, in modern networks, RIP is largely obsolete, replaced by more advanced protocols like OSPF and EIGRP.
Key terms in plain language
Open a term for a concise explanation of language used on this page.
Fiber Internet
Internet delivered through strands of glass using light. Fiber commonly supports high capacity, low latency, and strong upload performance, but availability must be confirmed for the exact address.
Bandwidth
The amount of data a connection can carry in a given time, usually measured in Mbps or Gbps. More bandwidth supports more users, devices, and simultaneous applications.
Broadband
A general term for always-on, high-speed Internet access. Broadband can be delivered over fiber, cable, DSL, fixed wireless, cellular, or satellite networks.
Latency
The time it takes data to travel between two points. Lower latency improves voice, video meetings, cloud applications, gaming, and other real-time services.
Dedicated Internet Access (DIA)
A business-grade Internet connection with capacity dedicated to the customer rather than shared in the same way as typical consumer broadband. It often includes symmetrical speeds and an SLA.
SD-WAN
Software-defined wide area networking. It manages multiple connections and chooses paths based on application needs, performance, and policy to improve resilience and control.