Subj : FidoNews submission To : Michiel van der Vlist From : Alex Galiyev Date : Fri May 30 2025 10:25 am Hello Michiel! Friday May 30 2025 11:32, you wrote to me: AG>> Tell this to our Comcast ISP users in Pennsylvania, in order to AG>> get better speeds, they have to disable ipv6. MV> Then Comcast and/or their users are doing something wrong. Native IPv6 MV> is definitely not slower than IPv4. It's definitely slower by design: - Bigger headers (40 B vs. 20 B) add per-packet overhead. - Path MTU Discovery failures (blocked ICMPv6 "Too Big") lead to drops/retries. - Transitional tunnels (e.g. 6in4, Teredo) introduce extra hops and encapsulation cost. - Less hardware offload and OS-stack tuning for IPv6 vs. decades of IPv4 optimizations. Alex --- GoldED+/W64-MSVC 1.1.5-b20250409 * Origin: Glory to Ukraine! Glory to Heroes! Dump Trump! (1:129/14.1) .