IP R
OUTING
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rough estimate of transmission cost. Each router broadcasts its
advertisement every 30 seconds, together with any updates to its routing
table. This allows all routers on the network to learn consistent tables of
next hop links which lead to relevant subnets.
OSPFv2 Dynamic Routing Protocol
OSPF overcomes all the problems of RIP. It uses a link state routing
protocol to generate a shortest-path tree, then builds up its routing table
based on this tree. OSPF produces a more stable network because the
participating routers act on network changes predictably and
simultaneously, converging on the best route more quickly than RIP.
Moreover, when several equal-cost routes to a destination exist, traffic can
be distributed equally among them.
Non-IP Protocol Routing
The switch supports IP routing only. Non-IP protocols such as IPX and
Appletalk cannot be routed by this switch, and will be confined within
their local VLAN group unless bridged by an external router.
To coexist with a network built on multilayer switches, the subnetworks for
non-IP protocols must follow the same logical boundary as that of the IP
subnetworks. A separate multi-protocol router can then be used to link the
subnetworks by connecting to one port from each available VLAN on the
network.
Basic IP Interface Configuration
To allow routing between different IP subnets, you must enable IP Routing
as described in this section. You also need to you define a VLAN for each
IP subnet that will be connected directly to this switch. Note that you must
first create a VLAN as described under “Creating VLANs” on page 3-188
before configuring the corresponding subnet. Remember that if you need
to manage the switch in-band then you must define the IP subnet address
for at least one VLAN.