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OSPF BDR and DR-OTHER relations

Hello,

 

I was wondering if DR have FULL relation with all other routers BDR and DR-OTHER, then what relation is between the BDR and DR-OTHER ? Is it also full or its 2WAY and it is switching to FULL when BDR becomes DR ?

6 REPLIES
Engager

Re: OSPF BDR and DR-OTHER relations

Hi,

all routers form full adjacencies with DR and BDR on broadcast- and NBMA networks.

Link: RFC 2328 Section 7.4: The Backup Designated Router

 

Regards,

Rolf

Re: OSPF BDR and DR-OTHER relations

Hello,

But what is the relation between BDR and DR-OTHER, 2WAY or FULL ?

Engager

Re: OSPF BDR and DR-OTHER relations

Full.

Engager

Re: OSPF BDR and DR-OTHER relations


all routers form full adjacencies with DR and BDR on broadcast- and NBMA Networks.


Perhaps I should have been clearer.

All routers (DR, BDR, DROther) form full adjacencies (only) with neighbor routers which are the DR or the BDR for that network.

Hall of Fame Master

Re: OSPF BDR and DR-OTHER relations

DR always forms full adjacency with all other OSPF routers on that segment (BDR and DR-other).

BDR always forms full adjacency with all other OSPF routers on that segment (DR and DR-other).

DR-other forms full adjacency with DR and BDR and 2 way with other DR-other.

If DR fails then BDR becomes new DR and already has full adjacency with all other OSPF routers on that segment.

A new BDR is selected and the new BDR forms full adjacency with all other OSPF routers on that segment.

 

HTH

 

Rick

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VIP Advisor

Re: OSPF BDR and DR-OTHER relations

Hello

DR/BDR = Full/BDR
BDR/DR = Full/DR
DR/Drother = Full/DROTHER
Drother/DR = Full/DR
Drother/BDR = Full/BDR
Drother/Drother = 2WAY/DROTHER

 

 



kind regards
Paul

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