With reference to Cisco SD-WAN, how do you prevent routing loops in iBGP? Refer to the scenerio in the topology below:
For the case where two routers at the same site are iBGP neighbors, SD-WAN has a built-in loop-prevention mechanism in order to prevent a routing loop from OMP to BGP and back from BGP to OMP.
BGP is a protocol that allows routers to exchange routing information and determine the best path for packets to take through a network. However, BGP can sometimes create routing loops, where packets get stuck in an endless loop between routers. This can lead to poor network performance and even network downtime.
Site of Origin (SoO) loop prevention is a mechanism that prevents routing loops by using a unique Site ID (SID) to mark the routes that are advertised by a particular site. The SID is attached to the BGP update as a BGP attribute. When a router receives a BGP update, it checks the SoO attribute to see if the SID matches its own. If the SID matches, the router discards the update to prevent a loop from occurring.
The send-community <both|extended> command must be configured on the neighbor statement in all devices.
SoO loop prevention is important in Cisco SD-WAN because it helps to ensure that packets are routed efficiently and effectively across the network. Without SoO loop prevention, routing loops could occur and cause network performance issues or even network downtime.
Overall, BGP loop prevention and SoO loop prevention are critical features of Cisco SD-WAN that help to ensure efficient and effective network performance, while simplifying network management and reducing the risk of network downtime.