TRILL RBridge Architecture
The RBridge Approach to Solving
the TRILL Problem
Goals in this Iteration
• Nail down terms and definitions,
• Eliminate complex interactions with other
protocols and technologies and make a few
choices,
• Step forward in defining what must be specified
in solution documents (Fill-in Architectural
detail),
• Seek input/guidance for future changes and
• Accept as a working group document
Terms & Definitions
• Broken into 2 sections, the first provides specific
definitions of existing terminology as they apply to
RBridges
– 802, Ethernet and LAN terminology
– Basic Link-State Routing terminology
• The second section defines RBridge specific terminology
– especially those that have seemed controversial in
dicussion on the list
– Relating to RBridge forwarding
• Ingress RBridge Tree – replaces the often confusing references to
RBridge spanning trees
• Forwarding Tunnels
– “Campus” related terminology including various logical tables
– RBridge roles – Edge (Ingress, Egress), DR, Cooperation
Complicated Interactions
• Reduce the amount of specification required for interworking with other technologies by defining an abstract
“co-located functionality” model
– Co-located Bridge (potential STP/RSTP BPDU interactions) –
allows us to use “block STP” mode only for an abstract RBridge
(see section 4.8).
• Define as optional/allowed functionality, those
capabilities relating to optimization
– IRT (Ingress RBridge Tree) Pruning
• VLAN Pruning
• Multicast Pruning
– Flooding Optimization
– ARP/ND Optimization
Architectural Detail
• Logical Tables
– Details on logical content for unicast (CFT) and
flooding/multicast/broadcast (CFT-IRT) logical tables
for various RBridge roles
• Details on:
– topology discovery,
– progression toward operating status –
• Auto-configuration, peer & topology discovery, SPF and IRT
computation, learning and forwarding
– Forwarding
• Population of the CFT and CTT
• Uses of the CFT and CFT-IRT
• Added content to “Conclusions” section.
Future Changes?
• Input on specific sections?
• Further abstraction
– Co-located VLAN (bridging and routing)
• Add More details on VLAN interactions with
CFT-IRT (section 4.6.2).
• Add More details on Optimizations?
• Complete section 5 (How this architecture
addresses the problem statement.
• Standard or Informational?
Finally
• Accept as a working group document?