On Mon, Dec 1, 2025 at 11:09 PM Vasilenko Eduard via NANOG <[email protected]> wrote: > Fundamentally, IPv6 should be slower because of the bigger headers/overhead.
Hi Vasilenko, Everything else being equal, IPv6 would have roughly 1.3% less throughput. The math is straightforward: 20 bytes larger header on 1500 byte packets, 20/1500 = 0.013 for throughput. The latency difference is determined by the total packet size including header and data which is the same or smaller with IPv6 -- both are limited by the 1500 byte Ethernet frame size. Even on the initial packets smaller than the frame size, the difference in transmission time over gigabit or better links is so small it disappears into the noise. So, no impact at all. That's it. If you're experiencing slower IPv6 or slower IPv4, it's all about the network engineering. Your network path to a server which satisfies one address is longer or transits a slower link in the path than the one which satisfies the other. Regards, Bill Herrin -- For hire. https://bill.herrin.us/resume/ _______________________________________________ NANOG mailing list https://lists.nanog.org/archives/list/[email protected]/message/PFRZ6MIJJJQ7FWI5BL4V5WOCOH6WK3ZY/
