Ubuntu increase UDP buffer size to 25MB 2021 and 2022 (multicast network card sysctl)

https://medium.com/@CameronSparr/increase-os-udp-buffers-to-improve-performance-51d167bb1360

Check:

$ sysctl net.core.rmem_max

net.core.rmem_max = 212992

$ sysctl net.core.rmem_default

net.core.rmem_default = 212992

Set:

$ sudo sysctl -w net.core.rmem_max=26214400

net.core.rmem_max = 26214400

$ sudo sysctl -w net.core.rmem_default=26214400

net.core.rmem_default = 26214400