The “ip” command, aka the “iproute2” suite, offers a huge amount of functionality for managing the Linux network stack. The initial man page, “man ip”, gives an overview, and (at least on my current system) ends with references to more: SEE ALSO ip-address(8), ip-addrlabel(8), ip-ioam(8), ip-l2tp(8), ip-link(8), ip-maddress(8), ip-monitor(8), ip-mptcp(8), ip-mroute(8), ip-neighbour(8), ip-netns(8), ip-ntable(8), ip-route(8), ip-rule(8), ip-stats(8) ip-tcp_metrics(8), ip-token(8), ip-tunnel(8), ip-vrf(8), ip-xfrm(8) IP Command reference ip-cref.ps That “ip-cref.ps” file doesn’t seem to be included in any Debian packages I can see. However, when I look in the /usr/share/man/man8 directory, I find a few more man pages not mentioned in the above list: ip-nexthop.8.gz ip-fou.8.gz ip-macsec.8.gz ip-gue.8.gz (symlink to ip-fou.8.gz) ip-netconf.8.gz ip-sr.8.gz That “ip fou”/“ip gue” command lets you tunnel arbitrary IP protocols over a pair of UDP ports. The home page for online docs is at <https://wiki.linuxfoundation.org/networking/iproute2>. Among the links is this nice step-by-step intro to doing some useful things with it <https://lartc.org/howto/lartc.iproute2.html>.