From: Peter van Oene (pvo@xxxxxxxxxxxx)
Date: Sun Jul 21 2002 - 13:01:55 GMT-3
The OSPF metric is dimensionless. That is to say its value is not designed
to relate to any physical property. Most implementations, including Cisco,
will automatically derive a value based upon the configured bandwidth of a
link. However, this is the absolute configured bandwidth of the link, not
the current bandwidth available. In other words, OSPF does not use a real
time, utilization based metric. Doing so would most likely yield a lot of
SPF churn as traffic moved around and produce a reasonably unstable network.
Pete
At 11:20 AM 7/17/2002 -0700, Shuyi Li wrote:
>Jason,
>
>Regarding the OSPF metric, I have a question for you that, the cost of
>links is considered to be the current available BW, or just the total BW
>even it's being occupied, say 50%. Please advise.
>
>thanks in advance.
>/shuyi
>
>
>At 05:22 PM 7/17/2002 +1000, Jason Sinclair wrote:
>>Tom,
>>
>>In OSPF the metric is the cost. What I mean here is best clarified as
>>follows:
>>
>>1. In RIP the metric as we know is hop count.
>>2. EIGRP/IGRP use a composite metric based on things such as bandwidth,
>>delay, etc
>>3. In OSPF the metric is based on the cost of links. The lower the cost the
>>more preferred the path
>>
>>Hope this makes sense.
>>
>>Regards,
>>
>>Jason Sinclair CCIE #9100
>>Manager, Network Control Centre
>>POWERTEL
>>55 Clarence Street,
>>SYDNEY NSW 2000
>>AUSTRALIA
>>office: + 61 2 8264 3820
>>mobile: + 61 416 105 858
>>email: sinclairj@powertel.com.au
>>
>>-----Original Message-----
>>From: Tom Young [mailto:gitsyoung@yahoo.co.jp]
>>Sent: Wednesday, 17 July 2002 16:35
>>To: ccielab@groupstudy.com
>>Subject: OSPF 's cost and metric
>>
>>Hi, group.
>>
>> The OSPF's "cost" and "metric" parameters made me
>>confused. Who can clear it for me?
>>
>>
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