Telindus 1031, Руководство пользователя и справочник

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Telindus 1031 Router Chapter 10
Reference manual Configuration attributes
205
telindus1031/router/ripHoldDownTime
Use this attribute to set the time the Telindus 1031 Router has to hold a
route down in case it receives a RIP update message declaring this route
down.
What is the RIP hold-down time?
Suppose you have a situation as depicted in the fig-
ure alongside.
Now suppose the following happens:
1. Route X goes down.
⇒
Router A sends a RIP update message to
router B declaring route X down.
2. Only a few moments later, route X goes up for a
while after which it goes down again. This continues for a certain time. In other words, the route status
toggles between up and down.
⇒
Every time the status of route X changes, Router A sends a RIP update message to router B. Also
router B propagates these RIP update messages. In other words, the toggling of route X causes
that a lot of RIP update messages are sent.
The
ripHoldDownTime
attribute tries to avoid situations as described above. Suppose router B has a
ripHoldDownTime
attribute. In that case, the situation is as follows:
1. Route X goes down.
⇒
Router A sends a RIP update message to router B declaring route X down. Router B starts the RIP
hold-down timer.
2. The status of route X starts toggling between up and down.
⇒
Router A sends several RIP update messages concerning route X to router B. Router B holds the
status of route X down, as longs as the RIP hold-down timer has not expired.
When the RIP hold-down timer expires and the route is …
• down, then the route status stays down.
• up, then the route status changes to up.
Default:00000d 00h 03m 00s
Range: 00000d 00h 00m 00s -
00000d 00h 10m 00s
network
router Z
router A
router B
route X