What is the default sending interval of BFD packets?

The default sending interval of Bidirectional Forwarding Detection (BFD) packets is indeed 1000 ms. BFD is designed to rapidly detect faults in the path between adjacent forwarding engines, which effectively improves the overall network reliability. By sending control packets at a regular interval, BFD can quickly inform routers of any connectivity issues that might arise, which helps in maintaining an efficient routing protocol.

In typical network configurations, the initial interval is set to a default of 1000 milliseconds (or 1 second) to strike a balance between timely fault detection and minimizing unnecessary traffic overhead. Reducing the interval further, like to 100 ms, would lead to increased processing load and higher bandwidth consumption, while longer intervals may lead to slower detection of link failures.

The other options, such as 5 seconds or 100 ms, do not represent the standard intervals for BFD packet transmission. While 'ios' appears to be an unrecognizable option in this context, the correct choice aligns with the established norms for BFD operation. Understanding the mechanics and default settings of protocols like BFD is essential for effective network management and troubleshooting.