Hi Tomáš, On 19 October 2017 at 12:17, Tomas Pospisek <tpo@xxxxxxxxxxxxx> wrote: > Hello all, > > On Wed, 18 Oct 2017, Michael Kerrisk (man-pages) wrote: > >> Hello all, >> >> Long ago (http://www.spinics.net/lists/linux-man/msg03193.html), Tomáš >> started work on a veth.4 page, and Eric through in some comments as >> well, but the effort to complete the page petered out. I decided to >> take a shot at picking up what was said so far completing it. > > Very nice, thanks! > >> Are there any comments on the page below? > > Based on the principle that I prefer useful to mathematically orthogonal man > pages, I'd suggest to document how you actually do create a veth in a > different network namespace: Agreed. >> Cheers, >> >> Michael >> >> veth(4) Linux Programmer's Manual veth(4) >> >> NAME >> veth - Virtual Ethernet Device >> >> DESCRIPTION >> The veth devices are virtual Ethernet devices. They can act as >> tunnels between network namespaces to create a bridge to a physi‐ >> cal network device in another namespace, but can also be used as >> standalone network devices. >> >> veth devices are always created in interconnected pairs. A pair >> can be created using the command: >> >> # ip link add <p1-name> type veth peer name <p2-name> >> >> In the above, p1-name and p2-name are the names assigned to the >> two connected end points. >> >> Packets transmitted on one device in the pair are immediately >> received on the other device. When either devices is down the >> link state of the pair is down. >> >> veth device pairs are useful for combining the network facilities >> of the kernel together in interesting ways. A particularly inter‐ >> esting use case is to place one end of a veth pair in one network >> namespace and the other end in another network namespace, thus >> allowing communication between network namespaces: > > > First you create the veth as above and then you move one side of > the pair to the other namespace: > > # ip link set <p2-name> netns <p2-namespace> Thanks. I added that. >> ethtool(8) can be used to find the peer of a veth network inter‐ >> face, using commands something like: >> >> # ip link add ve_A type veth peer name ve_B # Create veth pair >> # ethtool -S ve_A # Discover interface index of peer >> NIC statistics: >> peer_ifindex: 16 >> # ip link | grep '^16:' # Look up interface >> 16: ve_B@ve_A: <BROADCAST,MULTICAST,M-DOWN> mtu 1500 qdisc ... >> >> SEE ALSO >> clone(2), ip(8), ip-link(8), ip-netns(8) > > > Thanks a lot Michael & best greetings! Cheers, Michael PS Maybe catch up with you someday again in Bern? I'm there now and then. -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/ -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
