Fast convergence in singly-homed ethernet virtual private networks

摘要

In general, techniques are described for performing a mass withdrawal of media access control (MAC) addresses using a reduced number of route withdrawal messages within a singly-homed segment of an Ethernet Virtual Private Network (EVPN). The techniques may include determining a segment identifier of the segment and sending a route advertisement to advertise a route for the segment identifier to a provider edge network device. The techniques may include sending a route advertisement to advertise one or more media access control (MAC) routes for the layer two segment. The techniques may also include, responsive to determining a link failure between a first provider edge network device and a customer edge network device, sending a withdrawal message to the second provider edge network device for the route associated with the segment identifier to withdraw all of the plurality of MAC routes at the second provider edge network device.

主权项

1. A method comprising:
determining, by a first provider edge network device to which a customer edge network device is singly-homed in a layer two segment of an Ethernet Virtual Private Network (EVPN), a segment identifier of the layer two segment; sending, by the first provider edge network device and using a layer three (L3) routing protocol, a route advertisement to advertise a route for the segment identifier to a second provider edge network device included in the EVPN; sending, by the first provider edge network device and to the second provider edge network device using the layer three L3 routing protocol, a route advertisement to advertise one or more media access control (MAC) routes for the layer two segment, wherein each of the MAC routes specifies at least one MAC address reachable through the customer edge network that is singly-homed to the first provider edge network device; responsive to determining a link failure between the first provider edge network device and the customer edge network device:
flushing, by the first provider edge network device, one or more MAC routes associated with the segment identifier that were previously learned by the first provider edge network device;sending, by the first provider edge network device and using the L3 routing protocol, a withdrawal message to the second provider edge network device for the route associated with the segment identifier to withdraw all of the plurality of MAC routes at the second provider edge network device, wherein the segment identifier corresponds to the one or more MAC routes maintained by the second provider edge network device that were previously learned by the first provider edge router; and learning, by the first provider edge network device and after flushing the one or more MAC routes, a new MAC route associated with the segment identifier.