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Verifying RIP v2

Verifying RIP v2 1.2.5 The show ip protocols and show ip route commands display information about routing protocols and the routing table. This page explains how show commands are used to verify a RIP configuration. The show ip protocols command displays values about routing protocols and routing protocol timer information associated with the router. In the example, the router is configured with RIP and sends updated routing table information every 30 seconds. This interval is configurable. If a router running RIP does not receive an update from another router for 180 seconds or more, the first router marks the routes served by the non-updating router as being invalid. The holddown timer is set to 180 seconds. Therefore, an update to a route that was down and is now up could stay in the holddown state until the full 180 seconds have passed. If there is still no update after 240 seconds the router removes the routing table entries. The router is injecting routes for the net...

Configuring RIP v2

Configuring RIP v2 1.2.4  This page will teach students how to configure RIP v2. RIP v2 is a dynamic routing protocol that is configured by naming the routing protocol RIP Version 2, and then assigning IP network numbers without specifying subnet values. This section describes the basic commands used to configure RIP v2 on a Cisco router.  To enable a dynamic routing protocol, the following tasks must be completed: Select a routing protocol, such as RIP v2. Assign the IP network numbers without specifying the subnet values. Assign the network or subnet addresses and the appropriate subnet mask to the interfaces. RIP v2 uses multicasts to communicate with other routers. The routing metric helps the routers find the best path to each network or subnet. The router command starts the routing process. The network command causes the implementation of the following three functions: The routing updates are multicast out an interface. T...

Comparing RIP v1 and v2

Comparing RIP v1 and v2 1.2.3  This page will provide some more information about how RIP works. It will also describe the differences between RIP v1 and RIP v2. RIP uses distance vector algorithms to determine the direction and distance to any link in the internetwork. If there are multiple paths to a destination, RIP selects the path with the least number of hops. However, because hop count is the only routing metric used by RIP, it does not necessarily select the fastest path to a destination. RIP v1 allows routers to update their routing tables at programmable intervals. The default interval is 30 seconds. The continual sending of routing updates by RIP v1 means that network traffic builds up quickly.  To prevent a packet from looping infinitely, RIP allows a maximum hop count of 15. If the destination network is more than 15 routers away, the network is considered unreachable and the packet is dropped. This situation creates a scalability issue when routing in large ...

RIP v2 feature

RIP v2 feature 1.2.2  This page will discuss RIP v2, which is an improved version of RIP v1. Both versions of RIP share the following features: It is a distance vector protocol that uses a hop count metric. It uses holddown timers to prevent routing loops – default is 180 seconds. It uses split horizon to prevent routing loops. It uses 16 hops as a metric for infinite distance. RIP v2 provides prefix routing, which allows it to send out subnet mask information with the route update. Therefore, RIP v2 supports the use of classless routing in which different subnets within the same network can use different subnet masks, as in VLSM. RIP v2 provides for authentication in its updates. A set of keys can be used on an interface as an authentication check. RIP v2 allows for a choice of the type of authentication to be used in RIP v2 packets. The choice can be either clear text or Message-Digest 5 (MD5) encryption. Clear text is the default. MD5 can be use...

RIP Version 2 (RIP history)

RIP Version 2 RIP history 1.2.1  This page will explain the functions and limitations of RIP. The Internet is a collection of autonomous systems (AS). Each AS is generally administered by a single entity. Each AS has a routing technology which can differ from other autonomous systems. The routing protocol used within an AS is referred to as an Interior Gateway Protocol (IGP). A separate protocol used to transfer routing information between autonomous systems is referred to as an Exterior Gateway Protocol (EGP). RIP is designed to work as an IGP in a moderate-sized AS. It is not intended for use in more complex environments. RIP v1 is considered a classful IGP. RIP v1 is a distance vector protocol that broadcasts the entire routing table to each neighbor router at predetermined intervals. The default interval is 30 seconds. RIP uses hop count as a metric, with 15 as the maximum number of hops. If the router receives information about ...

Configuring VLSM

Configuring VLSM 1.1.6 This page will teach students how to calculate and configure VLSM. If VLSM is the scheme chosen, it must then be calculated and configured correctly.  The following are VLSM calculations for the LAN connections in Figure : Network address: 192.168.10.0 The Perth router has to support 60 hosts. That means a minimum of six bits are needed in the host portion of the address. Six bits will yield 2 6 – 2, or 62 possible host addresses. The LAN connection for the Perth router is assigned the 192.168.10.0/26 subnet. The Sydney and Singapore routers have to support 12 hosts each. That means a minimum of four bits are needed in the host portion of the address. Four bits will yield 2 4 – 2, or 14 possible host addresses. The LAN connection for the Sydney router is assigned the 192.168.10.96/28 subnet and the LAN connection for the Singapore router is assigned the 192.168.10.112/28 subnet. The...