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Can't change designated route in OSPF

Posted: Wed Mar 06, 2013 11:14 am
by iDen
In my network i have router with 3 outgoing interfaces.
1 - directly connected to backbone, 14 neighbors, bad wifi link
2 - has 1 hope to backbone, 1 neighbor, good wifi + optics
3 - has 2 hopes before backbone 1 neighbor, # wifi links

I want to pass traffic on the second link coz of its quality which is much better then link #1.

I'm changing costs of ospf interfaces , even tried to rise priority of interface.

But still ether1 has state "DR other", and all traffic passed to it.
Other 2 interfaces have "backup" state

ether1 - cost 20, priority 1
ether2 - cost 10, priority 10
ether3 - cost 30, priority 1

Please help.

Re: Can't change designated route in OSPF

Posted: Wed Mar 06, 2013 11:24 am
by mrz
DR and backup does not mean that the link is pirmary or backup. It is for different purpose.

You need to adjust link costs to make a specific link primary.
Here you can find how link costs are calculated
http://wiki.mikrotik.com/wiki/Manual:OS ... alculation

Re: Can't change designated route in OSPF

Posted: Wed Mar 06, 2013 11:58 am
by iDen
Yeah i know about this article.
This thing looks and should be trivial.
Interface with lower cost should override interface with higher cost but nothing happens.
Desired interface accepts inetrface only while i'm doing some changes to this "primary" interface. After this unwanted interface finishes it's recalculation traffic again passed back to this interface.

Maybe i still not doing something right?
Maybe you have some other small real life example?
DR and backup does not mean that the link is pirmary or backup. It is for different purpose.

You need to adjust link costs to make a specific link primary.
Here you can find how link costs are calculated
http://wiki.mikrotik.com/wiki/Manual:OS ... alculation

Re: Can't change designated route in OSPF

Posted: Sun Mar 10, 2013 7:07 am
by CelticComms
Look in your routing table and check if it is actually the OSPF routes that are not calculating as you expect - or is some other static entry causing confusion.

FYI - when an interface is set to DR, backup or DRother changing the priorities does not immediately cause an election so those statuses do not change immediately in response to priority changes - but they do once an election occurs. In any case those statuses are not related to the route costs.