SMC Networks 8926EM, Management Manual

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Unicast Routing
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estimating this delay. Set the transmit delay according to link speed, using larger
values for lower-speed links.
If this delay is not added, the time required to transmit an LSA over the link is not
taken into consideration by the routing process. On slow links, the router may send
packets more quickly than devices can receive them. To avoid this problem, you
can use the transmit delay to force the router to wait a specified interval between
transmissions.
• Retransmit Interval – Sets the time between resending link-state advertisements.
(Range: 1-65535 seconds; Default: 5 seconds)
A router will resend an LSA to a neighbor if it receives no acknowledgment after
the specified retransmit interval. The retransmit interval should be set to a
conservative value that provides an adequate flow of routing information, but does
not produce unnecessary protocol traffic. Note that this value should be larger for
virtual links.
Set this interval to a value that is greater than the round-trip delay between any two
routers on the attached network to avoid unnecessary retransmissions.
• Hello Interval – Sets the interval between sending hello packets on an interface.
This interval must be set to the same value for all routers on the network.
(Range: 1-65535 seconds; Default: 10)
Hello packets are used to inform other routers that the sending router is still active.
Setting the hello interval to a smaller value can reduce the delay in detecting
topological changes, but will increase routing traffic.
• Rtr Dead Interval – Sets the interval at which hello packets are not seen before
neighbors declare the router down. This interval must be set to the same value for
all routers on the network. (Range: 1-65535 seconds; Default: 40, or 4 times the
Hello Interval)
The dead-interval is advertised in the router's hello packets. It must be a multiple
of hello-interval and be the same for all routers on a specific network.
• Cost – Sets the cost of sending a protocol packet on an interface, where higher
values indicate slower ports. (Range: 1-65535; Default: 1)
The interface cost indicates the overhead required to send packets across a
certain interface. This is advertised as the link cost in router link state
advertisements.
Routes are assigned a metric equal to the sum of all metrics for each interface link
in the route.
This router uses a default cost of 1 for all ports. Therefore, if you install a 10 Gigabit
module, you need to reset the cost for all of the 1 Gbps ports to a value greater
than 1 to reflect the actual interface bandwidth.
• Authentication Type – Specifies the authentication type used for an interface.
(Options: None, Simple password, MD5; Default: None)
Use authentication to prevent routers from inadvertently joining an unauthorized
area. Configure routers in the same area with the same password (or key). All
neighboring routers on the same network with the same password will exchange
routing data.