Hello, On Fri, 17 Jan 2025 at 19:13, Brandon Martin <lists.nanog@monmotha.net> wrote:
Does anyone know of a good way to simulate oddball TCP happenings like:
* Out of order delivery * Variable delivery delays
I would suggest to take a look at linux tc-netem
* (Especially) Unusual segmentation e.g. splitting part of a stream that would and should normally be sent in a single segment into several smaller segments sent back-to-back
And especially doing so with traffic from an existing TCP-speaking application i.e. something like a TCP proxy that lets you deliberately mess with the segmentation and delivery order.
This is more difficult because a TCP proxy (as in a userspace application) does not do the TCP segmenting, the kernel does. Sure the application may set flags like TCP_NODELAY to toggle Nagle, but beyond that the application has not really control over TCP segmentation. So a tool like this would basically need to reimplement TCP in userspace. Not sure something like this is out there. Lukas