[rbridge] Existing issues in root bridge selection for LANs.

[Erik Nordmark]

Greg Daley wrote:
> Hi,
> 
> Here's the idea I was thinking about a while ago, which
> looks applicable to rbridge.  More work needs to be done,
> to ensure that the mean path cost is always lower, but
> I'd guess it's a fairly good bet to never be worse if
> most of the traffic exists the LAN.

Given that TRILL will use a use a link-state routing protocol to find 
the pair-wise shortest paths (without any configuration of any device), 
I don't see how this applies to TRILL.

Are your proposing some improvements to the IEEE 802.1 protocols?

> This means that all switches have the same default
> priority, and MAC addresses (as provided in the
> lower order bits of the switch's BridgeID),
> will be used to break ties between switches.
> 
> Therefore unless a manual priority configuration is
> provided, MAC switch vendors with the lowest IEEE OUI
> will win. 

My understanding is that manual configuration is used in enterprise 
Ethernets, which among other things ensure that the root bridge is close 
to the routers.

    Erik