MLAG vs vPC: 4 Key Differences
Both MLAG and vPC can create a port group between two switches and enable Layer 2 multipathing. In MLAG or vPC domain, each switch is managed and configured independently and is able to forward/route traffic without passing to a master switch. Despite their similarities, they still differ in some ways.
Difficulty of implementation : Obviously, the biggest difference between them is the difficulty of implementation. MLAG is a public protocol that is supported by almost every vendor using their own custom rolled implementation, while vPC is a Cisco Nexus specific protocol, not all the vendors have this technology. Thus, MLAG setup is a bit easier than vPC.
Compatibility issues : Another issue is compatibility. For vPC pairing, the same type of Cisco Nexus switches must be used. For example, it is not possible to configure vPC on a pair of switches including a Nexus 7000 series and a Nexus 5000 series switch. And the vPC peers must run the same NX-OS version except during the non-disruptive upgrade, that is, In-Service Software Upgrade (ISSU).
Layer multipathing : Besides, the vPC peer link must consist of at least two 10G Ethernet ports in dedicated mode. vPC is more advanced than MLAG. It supports both Layer 2 and Layer 3 multipathing, which allows you to create redundancy by enabling multiple parallel paths between nodes and load-balancing traffic where alternative paths exist. And if you want to enable Layer 3 multipathing, you could also use the Multi-Active Gateway Protocol (MAGP).
Application scenarios : Normally, vPC can only be used on Cisco Nexus data center switches, while MLAG can be applied to a wide range of scenarios. Whether in a traditional 3-tier data center architecture or a 2-tier spine-leaf architecture, switches that support MLAG can form an MLAG pair at different layers. All FS data center switches support MLAG. By using MLAG in data center network design, FS data center switches help deliver system level redundancy and improve network reliability.
| Item |
MLAG |
vPC |
| Simplifies Network Design |
Yes |
Yes |
| Eliminates Spanning Tree Protocol (STP) |
Yes |
Yes |
| Multipathing |
Layer 2 |
Layer 2 & Layer 3 |
| Difficulty of Implementation |
Easier |
Relatively Difficult |
| Switch Type for Pairing |
No requirement |
Strict Requirements |
| Using Scenarios |
Common seen in distribution or data center switches |
Usually in Cisco Nexus data center switches |
