TOI Author :: Shamit Kapadia

EVPN VXLAN all-active multihoming (AA-MH) provides redundancy to reduce or eliminate the impact of outages and maintenance. The objective of Maintenance Mode on AA-MH is to gracefully drain away the traffic from the EVPN core flowing through a switch that is part of multihoming while the switch is put into maintenance, and to gracefully add it back into the network and attract traffic again once the switch is out of maintenance. During the maintenance cycle any customer edge Ethernet or Port-Channel interfaces, whether they are participating as ethernet segments or not, can also be put into maintenance mode. Doing so eliminates the northbound traffic from the customer edge from flowing through the switch under maintenance. The traffic will instead take a path through other available multi-homing peers.

BGP Monitoring Protocol (BMP) allows a monitoring station to connect to a router and collect all of the BGP announcements received from the router’s BGP peers. The announcements are sent to the station in the form of BMP Route Monitoring messages generated from path information in the router’s BGP Adj-Rib-In tables.

Routing Control Functions (RCF) is a language that can be used to express route filtering and attribute modification logic in a powerful and programmatic fashion. The document covers:

Routing Control Functions (RCF) is a language that can be used to express route filtering and attribute modification logic in a powerful and programmatic fashion.

To understand why BGP-LU tunnels are required to be redistributed into LDP and vice versa, let’s consider the following basic topology for InterAS Option C. It uses IS-IS as IGP where indicated along with LDP:

In EVPN deployment with VXLAN underlay when an EVPN type 5 prefix is imported into an IP VRF, the IGP cost of the underlay

In an MLAG setup, routing on a switch (MLAG peer) is possible using its own bridge/system MAC, VARP MAC or VRRP MAC. When a peer receives an IP packet with destination MAC set to one of the aforementioned MACs, the packet gets routed if the hardware has enough information to route the packet. Before introducing this feature, if the destination MAC is peer’s bridge MAC, the packet is L2 bridged on the peer-link and the routing takes place on the peer. This behavior to use the peer-link to bridge the L3 traffic to the peer is undesirable especially when the MLAG peers can route the packets themselves.