What are the key functions of a router?
- routing mechanism
- dynamic routing support
- process program
What is the method for a routing mechanism?
Table search method
Routers provide dynamic support for what four things?
- RIP, OSPF, EGP, BGP
- information exchange protocols
- routers that send and receive info from other routers
- router table copy
What are the two types of process programs?
- routed daemon
- gated daemon for UNIX
What do routed and gated daemon for UNIX do?
apply routing policy: what to change, add, or subtract on the table
T/F: RIP is an Interior Gateway Protocol.
True
T/F: RIP is a distance vector/link state protocol.
False. Distant vector, not link state.
What does RIP contribute to?
Updating routing tables. Routers send all or part of their routing tables to their neighbours.
What do routing table updates contain?
- destinations
- next hop IP addresses
- hop count metrics
T/F: RIP is suited for large networks because it uses little bandwidth.
False. RIP is better suited to small networks where it is easy to implement and maintain.
How often do routers update their neighbours?
Every 30 seconds.
When was RIPv1 implemented and what were its limitations?
- before 1988
- high overhead
- supports standard subnetting
- slow convergence
- no support for EGP and BGP
- simple metric
- metric limited to 15
When was RIPv2 implemented and what are its highlights?
1993, updated in 1994
- resolved RIPv1 limitations except for small metric (intended for a small network)
- supports subnetting
- supports EGP/BGP
- supports multiple routing daemons
- supports a next-hop address option
- supports an authentication scheme
- supports multicasting and broadcasting
What are limitations for RIPv2?
- simplicity makes it better for small network
- simple metric
- metric limited to 15
- high overhead
Metric limited to 15 means what?
The maximum hop count is 15. 15 is the number of hops, no more and no less. Thou shalt not hop to 16, neither shou thou hop to 14 unless followed by 15… no, wait, you can hop to 14.
The Bellman-Ford algorithm is the basis for what?
The Distance Vector Protocol.
When is a route marked for deletion?
When a router notices a lack of table entry advertisement for 3 minutes. The route deletion is delayed through an update or something.
