OSPF BDR and DR-OTHER relations

[AlexandruMinzat7945]

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 ?

[Rolf Fischer]

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

[AlexandruMinzat7945]

Hello,

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

[Rolf Fischer]

Full.

[Rolf Fischer]

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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.

[Richard Burts]

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

[paul driver]

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