Since last few years the forwarding architecture inside the datacenter is changing rapidly and all the vendors are coming up with new technology which is shifting the overall conventional model of forwarding towards the new era… Now the technologies like STP or core resiliency technologies like VPC+,VSS, IST-SMLT (Avaya) aggregation etc are no more the buzz words of business meetings. In few years I have seen things changing and enterprise customers are rapidly adopting the new idea of data forwarding inside and even beyond the data centre.
There are many applications deployed into the datacenter which could not afford the latency of IP forwarding mechanism they need to have some other technology which requires less forwarding table lookups and can give same reliability. These applications can’t afford the high convergence time in case of failures they need to have multiple paths and need to load balance across all the paths unlike STP. For modern datacenter when the load is growing exponentially, we need to have a method which can give us the liberty to extend the layer two boundary to the other sites so that we can keep a check to the IP-based forwarding related latency.
Many vendors came with their own ideas which is being widely adopted by enterprise as well as the ISPs ….!!! Though no idea is new and while I am writing this blog people are already discussing another idea which can replace this one e.g. SDN ….but you may consider this term I am going to discuss is fairly new in market and not many people and aware of the working and configuration of it…The buzz word is SPBM or Shortest path bridging Mac (802.1aq).
You might have heard of the technologies like Fabric Path(Cisco) or Qfabric(Juniper) , there is very similar technology present as an open standard called SPB or shortest path bridging in RFC 6329 . This rfc extends the ISIS routing protocol support for the L2 style forwarding. By using this method we can have a extended LAN network across multiple data centers and can build complex layer 2 design very easily without even going through the brainstorming of STP operations. This STP free, fully connected(meshed) network provide great capabilities in terms of L2, L3 and multicast configurations with minimal configuration. Specially when you talk about multicast forwarding this technology has totally show stealer due to ease of configuration and troubleshooting of multicast enabled technology over the SPBM network.
I worked on Avaya SPBM and got the chance to see the technology working in lab so I have planned few blog posts to introduce you with the basic forwarding and configuration of it in Avaya switches.
This kind of forwarding is also called as Mac-in-Mac forwarding (802.1ah). And basically what it does is to encapsulate the PDU into the SPBM defined tags and forwarding happens on the basis of those labels into the spbm cloud….there are multiple ways we can implement SPBM and each way fits to a specific use case you want to build..for now Avaya has below flavors…
- Inter-VSN routing
- L3 VSN
- IP VPN-lite over SPB
- Multicast over SPBM.
In my next posts I would cover the basic operation and configuration of all of these one by one…so stay tuned and happy learning!!