TMS zl Management and Configuration Guide ST.1.1.100226

9-4
Routing
Static Routing
If the module learns about more than 10,000 total routes as a result of either
RIP or OSPF, routes after the 10,000th route will not be added to the routing
table. The excess routes will be “floating” routes, which means that they exist
but are not in the routing table. However, both routes in the routing table and
floating routes are shown in the Web browser interface and the CLI. See
“Viewing Unicast Routes” on page 9-53.
For example, if the module has 9,995 routes in the table and learns 10 routes
from RIP, only the first 5 routes it learns will be added to the routing table.
The other routes will become floating routes. However, all 10,005 routes will
be displayed in the Network > Routing > View Routes window.
Static Routing
The most straightforward method for constructing a routing table is static
routing. Static routes are routes that you manually add to the routing table.
Static routes must be configured on every routing device within a network.
Static routing is often dismissed as an outdated or cumbersome method of
routing. However, it is still a practical solution in many situations. For exam-
ple, it is practical for small networks with a limited number of links to outside
networks. Static routing is also practical for stub networks, which receive
traffic destined for their hosts, but do not pass any traffic to another network.
Static routing allows for predictable, easily controlled routing with a minimal
impact on your network. Advantages and disadvantages of static routing are
outlined in Table 9-1.
Table 9-1. Advantages and Disadvantages of Static Routing
Advantages Disadvantages
• Simple, predictable routes
• Supported on all routing devices
• Tighter control of routes: you
determine exactly which connection
the router uses to forward traffic to
each destination
• Protection against routing
convergence and route spoofing
• Not scalable
• High management overhead in large
networks, since configuring all the
necessary static routes can be
complicated and time consuming
• Does not adapt to new network
topology
• Does not automatically repair lost
connections, so the failure of a single
routing device can bring the entire
network down.