Blog
Notes from the network.
Whatever comes up in production or in the lab and seems worth explaining — troubleshooting, design decisions, and the things you only grasp on second look.
-
21 July 2026
MTU and MSS: when large packets disappear
The connection is up, but as soon as real data flows everything stalls. On path MTU discovery, blocked ICMP, and why MSS clamping at the tunnel is the practical fix.