I was asked offline about ospf metrics (please send to the list, not
directly to me).
"But I am a bit confused about setting metrics. Do we have to only
specify the bandwidth comamnd when u tune the metrics or is there some way
of doing it. I mean by playing with cost. If so, how to do this"
You can set the metrics either implicitly, by setting the bandwidth (in
which case the ospf cost will be calculated by the formula
(10**8)/bandwidth), or explicitly by using the 'ip ospf cost xxx' statement
as used in the config below.
If you set the cost explicitly (using the 'ip ospf cost xxx' statement),
the bandwidth statement does not affect the ospf metric.
For example, in the config given in the original post, the two interfaces
have an ospf cost explicitly configured - 'ip ospf cost 100'. The
bandwidth statement is ignored for ospf cost purposes. The two interfaces
have the same ospf cost (100), so traffic will be split between the links.
If the 'ip ospf cost 100' statements were removed from both interfaces,
then the bandwidth statements would be used to calculate the ospf cost.
The cost of the 2 Mbps interface would be 50 (10**8/2000000) and the cost
of the 1 Mbps interface would be 100 (10**8/1000000). The 2 Mbps interface
would be seen as lower cost and all traffic would use that link.
JMcL
----- Forwarded by Jenny Mcleod/NSO/CSDA on 11/12/2001 03:03 pm -----
"jenny.mcleod@centreli
nk.gov.au" To:
[EMAIL PROTECTED]
> Below is the configuration of my router. Serial 1/0 is a 2m link and
serial
> 1/1 is a 1m link . By configuring as given below, will I be able to
acheive
> load balance between these 2 links , I am running OSPF.
>
>
> interface Serial1/0
> description 1st 2M link
> bandwidth 2000
> ip address 172.31.0.60 255.255.255.252
> ip ospf cost 100
>
> !
> interface Serial1/1
> description 2nd 1M link
> bandwidth 1000
> ip address 172.31.0.61 255.255.255.252
> ip ospf cost 100
Message Posted at:
http://www.groupstudy.com/form/read.php?f=7&i=28804&t=28654
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