3Com OfficeConnect 3C840, User Manual

Page: 172 / 222

A-10 A
PPENDIX
A: B
RIDGING AND
R
OUTING
The algorithm will automatically select to forward the data packet via
Router A, as this route contains the least number of hop counts which
makes it the preferred direct route.
Every thirty seconds (by default), each IP router will advertise, via RIP
datagrams, to all other routers on the Internetwork, how many hops it
takes to reach all connected logical networks, based on the routers
network position and the state of its physical links.
It is also possible to assign what are known as static routes, which are
manually entered fixed routes. The network manager may be aware of
specific traffic patterns, or need to enforce a particular routing policy.
Static routes provide an option to force traffic through the network in a
particular way. The disadvantage with this approach is that routing
protocols dynamically update all the routers on the network with the
current network topology, enabling backup routes to be deployed. In a
static route situation, if the WAN links in that routing definition are down,
then traffic cannot be passed. Implementing a static route prohibits the
router from being able to offer alternative data paths.
840ug.book Page 10 Friday, July 7, 2000 2:23 PM