DVSR

Dynamically Verified Static Routing

Dynamically Verified Static Routing (DVSR) is a proprietary routing protocol of the former Redback (now Ericsson) available on SmartEdge and Smart Services Router products.

DVSR can be defined as a semi-dynamic and semi-static routing protocol.

A DVSR route is based on static routing principle, but the router regularly checks for the next hop availability before the prefix can be injected into the local routing table and redistributed towards other routing tables. The DVSR route configuration allows the setup of success and failure counters used to declare the route as active or not. It could be described as a number of DVSR router attempts to ping the next hop; in case of a given number of successful replies the route is added to the local routing table or, after a set number of consecutive failures, the route is withdrawn.

SmartEdge routers support DVSR as a unique edge routing feature in addition to static routing and regular IGPs, such as IS-IS, OSPF, and RIP. DVSR is similar to normal static routing. The main difference is that the DVSR's next hop, or some other relevant host IP address, is dynamically verified by this protocol before the prefix can be injected into the local routing table. In many ISP networks, using static routing without proper next-hop checks results in black holing of network traffic.