Showing posts from July, 2013

[TRILL] The keypoint for Appointed VLAN-x Forwarder

If you study a lot of TRILL related documents and still are not able to figure out what Appointed VLAN-x Forwarder is and what purpose it is for, please refer to the following excerpts about it.

Whether they run STP or not, the RBridges have to ensure there’s a single point of contact between a VLAN in the STP domain and the backbone, otherwise all the flooded packets would enter the backbone through multiple entry points, resulting in duplicate packets received by the remote hosts (which might break some odd fainthearted protocols running directly on top of L2). One of the RBridges therefore becomes an appointed forwarder for an edge VLAN. The right-hand part of the figure illustrates the appointed forwarder concept: the RBridges don’t participate in the STP, none of their edge ports are blocked, but only one of the RBridges acts as a forwarder between the edge STP domain and the TRILL backbone (marked with A), all other RBridges ignore packets received through that VLAN …

[OpenFlow] OpenFlow 1.3 Spec Summary

Compared with OF1.0, OF1.3 is more tables and complex design than 1.0. Here I try to summarize the main items in OF1.3 spec included the table, message, and so on for me to review it more quick in the future.

OpenFlow Table

Flow Table
 | Match Fields | Priority | Counters | Instructions | Timeouts | Cookie |

Group Table
 | Group Identifier | Group Type | Counters | Action Buckets |
  Group TypesRequired: all: Execute all buckets in the groupOptional: select: Execute one bucket in the group.Required: indirect: Execute the one defines bucket in this group.Optional: fast failover: Execute the first live bucket.Meter Table

[TRILL] TRILL Summary for TRILL Test Suite

The following item list is about the key points for each test case in the TRILL Interoperability Test Suite Document.
IS-ISFor Neighbor Info in Hello MessageAll RBridges must become adjacent with one another. TRB0 and TRB1 must list each other as neighbors in their TRILL Hellos on link 1. TRB1 and TRB2 must list each other as neighbors in their TRILL Hellos on link 3. TRB0 and TRB2 must list each other as neighbors in their TRILL Hellos on link 2.Designated RBridge Election is based on Priority and MAC Address to solve the tiebreakIncremental Deployment FunctionalityNickname Collision is solved by Priority, IS-IS System IDConfigure TRB1 and TRB2 to have an MTU of 1280 on link 3  The Campus Wide MTU Sz value must be 1280 on all RBridges. The orginatingLSPBufferSize in each RBridge’s LSP must be set to 1280.RBridges perform IP Snooping for multicast data TES3 sends multicast data for IPv4 multicast group on link 3. TES0 sends an IGMPv3 to exclude nothing for multicast group …