I've been trying to modernise my way with Linux by, for one thing, ditching netstat for ss. I looked up my favourite command line flag for netstat in the ss man pages, and was very glad to find that netstat -lnp is more or less the same command as ss -lnp. Or so I thought...# ss -lnp | grep 1812Turns up nothing, but# netstat -lnp | grep 1812udp        0      0 0.0.0.0:1812            0.0.0.0:*                           11103/radiusddoes. A fact that made that particular troubleshooting unnecessarily harder.Now I'm trying to understand how I should have used ss to verify that the daemon was listening.Can someone please explain?EDIT:# ss --versionss utility, iproute2-ss090324# ss -aunp | grep radiUNCONN     0      0                         *:50482                    *:*      users:((radiusd,11103,11))UNCONN     0      0                 127.0.0.1:18120                    *:*      users:((radiusd,11103,9))UNCONN     0      0                         *:1812                     *:*      users:((radiusd,11103,6))UNCONN     0      0                         *:1813                     *:*      users:((radiusd,11103,7))UNCONN     0      0                         *:1814                     *:*      users:((radiusd,11103,10))# ss -lnp | grep radi#
ss is replacing netstat, how can I get it to list ports similarly to what I am used to?
linux;networking;command line;socket;netstat
A recent version of ss should also display UDP listeners in that way. You can limit to UDP with ss -unlp.I have tried a recent Debian version where ss --version reports ss utility, iproute2-ss140804 and that does work.On A Red Hat 5 system with ss utility, iproute2-ss061002 it doesn't. You do get more info there using ss -aunp although that also shows connected ports.You can also try:ss -apu state unconnected 'sport = :1812'