Configuring an ESI
An ESI must be configured on a PE interface connected to a CE. The same ESI must be configured for PE interfaces connecting to the same CE.
Context
The PEs connecting to the same CE must have the same ESI configured. After PEs exchange routes that carry ESIs, a PE can be aware of the other PEs connecting to the same CE, helping implement load balancing or FRR.
The interface has been bound to an EVPN instance using the evpn binding vpn-instance command.
The interface is in the up state. Otherwise, Ethernet segment routes cannot be generated.
An ESI is statically set on the interface.
An ESI is dynamically generated on the interface.
Static configuration is recommended. Compared with dynamic ESI generation, static configuration allows EVPN to implement faster traffic switching during a DF election in a dual-homing scenario with active-active PEs.
In a single-homing scenario, features such as fast convergence, split horizon, and df election required in an EVPN dual-homing scenario do not take effect. Therefore, configuring an ESI on a single-homing PE is optional.
The format of a dynamically generated ESI is xxxx.xxxx.xxxx.xxxx.xxxx.xxxx, where x is a hexadecimal number starting at 01 and consisting of the LACP system MAC address and LACP port key value. The remaining bits are padded with 0.