For those people using RFC 4761 or LDP based signaling of Pseudowire VCs between ISP PE’s there is an additional method for speeding up establishment and recovery of your tunnels.
Packet loss can occur when the IGP and LDP aren’t synchronized. If the ISIS adjacency is established before the LDP then it will forward packets down a link that’s essentially a black hone. Or in the other case if the LDP session closes the PE could continue to forward packets at a black hole. Read more... (139 words, estimated 33 secs reading time)
Split Horizon is a pretty old concept. The first time I ever saw it applied was in Routing Information Protocol (RFC 1058) RIP.
It defined a way to deal with traffic that created loops in the logic.
There are several things that can be done to prevent problems like this. The ones used by RIP are called “split horizon with poisoned reverse”, and “triggered updates”.
Read more... (325 words, estimated 1:18 mins reading time)
Double taxation!!!! It’s an outrage. Outrageous I tell you. How does it happen? Well it’s sneaky. It’s done for both the consumer and the supplier. By dividing it up among two different groups perhaps it’s just below the threshold of pain that would cause people to cry foul the way they did with the ATM Cell tax. Read more... (670 words, estimated 2:41 mins reading time)
Ring based VPLS? Things that make you go hum? I reviewed this Draft document last week and was partialy perplexed on the intended role or need of this sort of Architecture. Today, in the marketplace we have lots of layer 2 models that will fit the role of this technology in the access layer, not so much in the core layer. In the Access, we’ve used RPR, MRP, REP, RSTP to name just a few. Some proprietary some not. All with very limited intelligence. The nice thing about the little intelligence is the lack of requirements that the device has and ergo the less amount of hardware is required to perform that function. For example the device that is asked to do Read more... (573 words, estimated 2:18 mins reading time)
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Draft IETF: Circular Logic – Ringed VPLS?
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PHAT! I like that word. But, it’s not quite the word I need to use it’s FAT-PW or flow aware transport pesudowire. A draft that was presented back in Mach of 09 and into ietf draft on the 23 of September. I haven’t been to the last few ietfs, so I hadn’t been paying enough attention and this one slipped past me. It hit my radar back in September when the announcement of the IETF draft hit and I reviewed it and sent my comments on to the author and to the vendor in general. Read more... (646 words, estimated 2:35 mins reading time)