Routing Information Protocol (RIP)

The Routing Information Protocol (RIP) facilitates the exchange of routing information on a NetWare internetwork. Like IPX, the RIP protocol was derived from XNS. However, an extra field, ``Number of ticks'', was added to the packet structure to improve the decision criteria for selecting the fastest route to a destination. This change prohibits the straight integration of NetWare's RIP with strictly conforming XNS implementations.

RIP broadcasts

The broadcast of RIP packets allows:

• workstations to locate the fastest route to a network number.

• routers to request routing information from other routers to update their own internal tables.

• routers to respond to route requests from workstations and other routers.

• routers to make sure that all other routers are aware of the internetwork configuration.

• routers to detect a change in the internetwork configuration.

For more information on routers and the functions they perform, see the Novell NetWare documentation.

RIP packet structure

The RIP packet structure is shown in Figure 4-5. This structure is enveloped within the data area of IPX.

Figure 4-5 RIP packet structure

The packet contains the following fields:

Operation

indicates whether the packet is a request or a response. A 1 in this field indicates a request; a 2 indicates a response.

Network Number

Identifies the network segment the packet will be sent to.

Number of Hops

Indicates the number of routers the packet must pass through to reach a network number.

Number of Ticks

Indicates how much time is required for the packet to reach the specified network segment. The number in this field is always at least one. (A ``tick'' is approximately 1/18 of a second; there are 18.21 ticks in a second.)

The ``Operation'' field can be followed by one or more sets of information, each consisting of a network number and the number of hops and ticks to that network number. A RIP packet can contain a maximum of 50 sets of network number information.

The original XNS definition of the RIP did not include the ``Number of Ticks'' field. The ``Number of ticks'' field was added by the developers of NetWare so that the NetWare shell could estimate how long it should wait for a response from a file server. Also, if multiple routes exist to a network number, a router uses the route with the smallest number of ticks when forwarding packets to that network number.

If a RIP packet is a request for information, only the ``Network Number'' field applies; the ``Number of hops'' and ``Number of ticks'' fields are essentially nulled out. A response packet can be either a reply to a request from a router or workstation or a periodic broadcast by a router.

Home Notes   Home   MCSE   MCSE + Security   CCNA   CCNP   Schedule   Register   Frequently Asked Questions   Course Fees   Contact US   Boot Camp Location   Compare us to our competitors   Testimonials   Sitemap

Testimonials

Join MCSE Boot Camp & CCNA Boot Camp Back to Back Certification Today. links  270    290    291  293    294  298  299  Security  640-801  routing 811  821   831  Resources MCSE + CCNA  Training  Card pay  Papal  MCSE Notes  CCNA Notes    index main  root link  resources home    Ref1 Ref2

Vibrant offers MCSE certification training boot camp for $5400 all inclusive, instructor led at California and Baltimore.

Vibrant Bootcamp Participants come from All Around the World. Vibrant has trained students from more than 15 countries like USA, UK, (Scotland, Ireland, Wales), Switzerland, Germany, Australia, Canada, France, Holland, Japan, Belgium, Bahrain, New Zealand, Tanzania, Turkey, Kenya and more.