Making another step towards enabling a world of truly open Ethernet switches, Mellanox recently became the first vendor to release as open source, implementation of Multi Chassis Link Aggregation Group, or as it is more commonly known – MLAG.
Mellanox is involved and contributes to other open source projects, such as OpenStack, ONIE, Puppet and others, and already contributed certain adaptor applications to the open source community. Mellanox is the first and only vendor to open-source its switch SDK API. Mellanox is also a leading member and contributor of the Open Compute Project, where it provides NICs, switches and software.
MLAG is a protocol stack that when run on the associated switches, enables a host to connect to these switches using a simple LAG, or bond, configuration. MLAG is typically used to provide high availability to the network and to reduce down time in events of failure of cables or switches, as shown in Figure 1. Given the network connectivity of active/active bond at the host, MLAG provides an additional benefit of inherent load balancing.
Given the common use of MLAG, almost every Ethernet switch vendor has its implementation of this function, and different vendors chose different names for it. However, while many vendors use the terms “open” and “SDN” frequently, none has opened a protocol like MLAG until now. In this closed situation, it is obvious that the “MLAG” of vendor X is different from vendor Y’s “MLAG”. We already know that many protocols, such as STP, OSPF, BGP and others can interoperate between switches from different vendors, so why should MLAG be different?
Today, it is not expected that MLAG-enabled switches would allow using them as an MLAG group. Essentially, you can change the word “MLAG” with almost every protocol that is vendor-specific and the picture would be the same. This can change, and will continue to change over time. Mellanox MLAG is one of the first steps in this direction and certainly not the last.
Multiple switch vendors, either by their own decision or by their customer demand, will be able to use the same software stack to implement the same function and there will be full interoperability. The benefit to the user is exactly the Open Ethernet vision – the freedom of choice and the ability to mix and match hardware and software – resulting in better utilization of the financial and managerial resources.