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OSPF cost value to reflect the actual 64k link berween two routers
- Thread starter metafox
- Start date
Hopefully I understand your question here but OSPF will automatically size up the OSPF cost for your 64k link based on its reference bandwidth parameter it uses to assign costs. The default reference bandwidth is 10^8 or 100mb.
OSPF therefore will automatically assign a cost of 100000000/64000 ~ 1500 to this link.
If you have a network with lots of small links, this reference bandwidth is fine. It becomes more of a problem where your network has lots of large links (Fast and Gig Ethernet). You can change the reference bandwidth using the command: ospf auto-cost reference-bandwidth <ref-bw> but, as I recall, all OSPF routers in your area must be configured with the same reference bandwidth.
Alternatively you can just use the command: ip ospf cost <cost> on the interface that terminates the 64k link and put in a manual figure that you feel is best if you want to do some kind of traffic engineering.
OSPF therefore will automatically assign a cost of 100000000/64000 ~ 1500 to this link.
If you have a network with lots of small links, this reference bandwidth is fine. It becomes more of a problem where your network has lots of large links (Fast and Gig Ethernet). You can change the reference bandwidth using the command: ospf auto-cost reference-bandwidth <ref-bw> but, as I recall, all OSPF routers in your area must be configured with the same reference bandwidth.
Alternatively you can just use the command: ip ospf cost <cost> on the interface that terminates the 64k link and put in a manual figure that you feel is best if you want to do some kind of traffic engineering.
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