3Com 4500G Series, Configuration Manual

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of the devices in a specified range, thus avoiding unlimited topology collection.
After the interval for collecting topology information is configured, the device collects the topology
information at this interval.
To avoid network congestion caused by large amounts of topology responses received in short periods:
z
Upon receiving an NTDP topology collection request, a device does not forward it, instead, it waits
for a period of time and then forwards the NTDP topology collection request on its first
NTDP-enabled port.
z
On the same device, except the first port, each NTDP-enabled port waits for a period of time and
then forwards the NTDP topology collection request after the previous port forwards the NTDP
topology collection request.
Follow these steps to configure NTDP parameters:
To do… Use the command… Remarks
Enter system view system-view —
Configure the maximum hops
for topology collection
ntdp hop hop-value
Optional
3 by default.
Configure the interval to collect
topology information
ntdp timer interval-time
Optional
1 minute by default.
Configure the delay to forward
topology-collection request
packets on the first port
ntdp timer hop-delay time
Optional
200 ms by default.
Configure the port delay to
forward topology collection
request on other ports
ntdp timer port-delay time
Optional
20 ms by default.
The two delay values should be configured on the topology collecting device. A topology collection
request sent by the topology collecting device carries the two delay values, and a device that receives
the request forwards the request according to the delays.
Manually Collecting Topology Information
The management device collects topology information periodically after a cluster is created. In addition,
you can configure to manually initiate topology information collection, thus managing and monitoring
the device on real time, regardless of whether a cluster is created.
Follow these steps to configure to manually collect topology information:
To do… Use the command… Remarks
Manually collect topology information ntdp explore Required