CAT 6500 Bridge Domain

[MUKUL JOSHI]

Hi All,

I was going through CAT 6500 switch documents...I have little doubt on Bridge Domain in SUP2T.How is it possible to reuse VLAN on a per port basis.

Can any one expain on this.

Thnx

BRegards

MJ

[Reza Sharifi]

Hi,

From sup-2T architect white paper:

Layer 2 - Bridge Domains

The bridge domain is a new concept that has been introduced with PFC4. A bridge domain is used to help scale traditional VLANs, as well as to scale internal Layer 2 forwarding within the switch. Bridge domains are mapped to each VLAN that a user configures, as well as other resources such as an EoMPLS/VPLS tunnel, L3 sub-interfaces, and multicast Egress replication-mode. In essence, a bridge domain is equal to a VLAN (which is a 12-bit ID, allowing 4096 unique values). Bridge domains use a 14 bit ID (12 bits are VLAN ID), for a total of 16 K bridge domains supported in hardware by the PFC4.

Layer 2 - Bridge Domains

The bridge domain is a new concept that has been introduced with PFC4. A bridge domain is used to help scale traditional VLANs, as well as to scale internal Layer 2 forwarding within the switch. Bridge domains are mapped to each VLAN that a user configures, as well as other resources such as an EoMPLS/VPLS tunnel, L3 sub-interfaces, and multicast Egress replication-mode. In essence, a bridge domain is equal to a VLAN (which is a 12-bit ID, allowing 4096 unique values). Bridge domains use a 14 bit ID (12 bits are VLAN ID), for a total of 16 K bridge domains supported in hardware by the PFC4.

More info:

http://www.cisco.com/en/US/prod/collateral/switches/ps5718/ps708/white_paper_c11-676346.html

HTH

[MUKUL JOSHI]

Hi Reza,

Thank you for your reply !!

Documents are not so clear..I want to know whether you came across these terms in your daily work, Bridge domain and Logical interfaces .....

What i understand is Bridge domain can be used to map vlan number.Does that mean we can use same vlan again?

have u came across such scenarios where i have to reuse same vlan...otherwise what is the exact use of bridge domain and logical interface.