Linux UDP max size of receive buffer

Question

What\'s the maximum size of Linux UDP receive buffer? I thought it\'s limited only by available RAM, but when I set

5GB for rmem_max:

echo 5000000000 >         


        

Answer 1

2^32-1 (2147483647, maximum 32bit signed integer)

root@root@localhost:~# sysctl -w net.core.rmem_max=2147483647
net.core.rmem_max = 2147483647

root@localhost:~# sysctl -w net.core.rmem_max=2147483648
sysctl: setting key "net.core.rmem_max": Invalid argument
net.core.rmem_max = 2147483648

Echoing into the /proc filesystem appears to overflow when attempting to set larger values.