This is the 64-bit version of cefAdjPkts, avoiding counter wraparound for adjacencies carrying enough traffic to overflow a 32-bit packet counter within a normal polling interval. On a busy core adjacency forwarding tens of millions of packets per minute, this 64-bit counter is the one that should actually be polled to get an accurate per-neighbor traffic reading rather than a wrapped, misleadingly low value. A core-facing adjacency moving 20 million packets per minute would wrap the 32-bit cefAdjPkts counter in just a few minutes, making this 64-bit version necessary for any meaningful polling interval.