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- Newsgroups: comp.dcom.sys.cisco
- Path: sparky!uunet!stanford.edu!agate!spool.mu.edu!cass.ma02.bull.com!jmills
- From: jmills@cass.ma02.bull.com (John Luke Mills)
- Subject: OSPF path costs vs. Bandwidth
- Message-ID: <1993Jan26.200238.16969@cass.ma02.bull.com>
- Organization: Bull World Wide Information Systems Inc.
- Date: Tue, 26 Jan 1993 20:02:38 GMT
- Lines: 38
-
-
- In my mostly OSPF network some of the OSPF interface costs are not
- what I expect. The interface costs of all my serial links are 1562.
- This is the correct value for 64kbps links. I don't have any 64kbps
- serial links. I have lots of 56's, some full t1's, and fraction t1's.
- I did not set any ospf costs and just took the defaults.
-
- The manual states that different physical interfaces have different
- defaults and provides a table of some common link speeds and metrics.
- It also states that the "no ip ospf cost" command resets the path cost
- for an interface to the default value.
-
- I took this to mean that by default ospf would determine the link
- speed of each interface and set the metric accordingly, but this
- didn't happen.
-
- It appears that this is not related to the bandwidth parameter for the
- interfaces. I never use any bandwidth commands and all my serial
- links report a bandwidth of 1544kbs, that for a full t1 link.
-
- Is OSPF supposed to be able to set the interface cost itself?
-
- If so, where does it get its information?
-
- If it is the bandwidth parameter, is this supposed to be set manually?
-
- On DTE interfaces is the bandwidth parameter supposed to be set
- automatically by looking at the provided clock?
-
- Most of my routers run 9.0(1) if it matters. Obviously this isn't a
- big deal since I can manually set any costs I want where it matters.
- I would like to know what is really supposed to be happening.
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