What is VLAN partition?

[Steve Zhou]

Hello all,

I saw this statement in some documents said "Certain configurations of bridges may cause partitions of a VLAN on a link. For such configuration, a frame sent by one bridge to a neighbor on that link might not arrive, if tagged with a VLAN that is parittioned due to bridge configuration."

What does VLAN partition mean? Could anyone share your understandings? thanks a lot!

[Peter Paluch · Accepted solution]

Hi Steve,

I have not yet encountered a similar term as VLAN partition. What the statement says, though, appears to me as a bridge misconfiguration where either the VLAN is not created on the bridge at all, hence the bridge will not forward frames in that particular VLAN (a common behavior for VLAN-aware switches), or the VLAN is created but is not configured to be bridged between a particular set of ports, resulting in two or more discontiguous domains.

Apart from this - I do not know

Best regards,

Peter

[Steve Zhou]

Hi Peter,

thanks for your help. I have the following up as below:

(1) The problem is mainly caused by  configuration issue on the bridge. I agree with you that the link bridge might be misconfigured which in turn partitioned a VLAN.

(2) How do you understand the workd "link" in the context? If let you draw a topology, would the "link" actually another bridge interconnecting other bridges.

(3) If we changed the bridges here to switches, would the result the same?

thank you

[Peter Paluch]

Hi Steve,

(2) How do you understand the workd "link" in the context? If let you draw a topology, would the "link" actually another bridge interconnecting other bridges.

I really do not know. Can you perhaps post a bigger section of the document where you read this, or if it is a public document, can you post a URL to it?

(3) If we changed the bridges here to switches, would the result the same?

Yes - in fact, I was talking about switches.

Best regards,

Peter

[Steve Zhou]

Actually, I'm reading RFC 6325 page 17. Anyway, thanks a lot for your help, Peter.

[Peter Paluch]

Hi Steve,

Oh, I see. In that case, the RFC 6325 in Section 1.3 indicates:

   In this document, the term "link", unless otherwise qualified, means
   "bridged LAN", that is to say, the combination of one or more [802.3]
   links with zero or more bridges, hubs, repeaters, or the like.  The
   term "simple link" or the like is used indicate a point-to-point or
   multi-access link with no included bridges or RBridges.

Does this explain your question?

Best regards,

Peter

[mhnedirli]

if you read sentence begining from end it says, if you configure vlan on a switch and a frame sent by one to a neighbor on that link might no arrive.

[Steve Zhou]

Hi mhnedirli,

sorry, I didn't get your points, do you have the same view as Peter?

thank you!