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Diffstat (limited to 'man4/veth.4')
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diff --git a/man4/veth.4 b/man4/veth.4 new file mode 100644 index 0000000..cbb2456 --- /dev/null +++ b/man4/veth.4 @@ -0,0 +1,86 @@ +.\" Copyright (c) 2012 Tomáš Pospíšek (tpo_deb@sourcepole.ch), +.\" Fri, 03 Nov 2012 22:35:33 +0100 +.\" and Copyright (c) 2012 Eric W. Biederman <ebiederm@xmission.com> +.\" +.\" SPDX-License-Identifier: GPL-2.0-or-later +.\" +.\" +.TH veth 4 2023-02-05 "Linux man-pages 6.05.01" +.SH NAME +veth \- Virtual Ethernet Device +.SH DESCRIPTION +The +.B veth +devices are virtual Ethernet devices. +They can act as tunnels between network namespaces to create +a bridge to a physical network device in another namespace, +but can also be used as standalone network devices. +.PP +.B veth +devices are always created in interconnected pairs. +A pair can be created using the command: +.PP +.in +4n +.EX +# ip link add <p1-name> type veth peer name <p2-name> +.EE +.in +.PP +In the above, +.I p1-name +and +.I p2-name +are the names assigned to the two connected end points. +.PP +Packets transmitted on one device in the pair are immediately received on +the other device. +When either device is down, the link state of the pair is down. +.PP +.B veth +device pairs are useful for combining the network +facilities of the kernel together in interesting ways. +A particularly interesting use case is to place one end of a +.B veth +pair in one network namespace and the other end in another network namespace, +thus allowing communication between network namespaces. +To do this, one can provide the +.B netns +parameter when creating the interfaces: +.PP +.in +4n +.EX +# ip link add <p1\-name> netns <p1\-ns> type veth peer <p2\-name> netns <p2\-ns> +.EE +.in +.PP +or, for an existing +.B veth +pair, move one side to the other namespace: +.PP +.in +4n +.EX +# ip link set <p2\-name> netns <p2\-ns> +.EE +.in +.PP +.BR ethtool (8) +can be used to find the peer of a +.B veth +network interface, using commands something like: +.PP +.in +4n +.EX +# \fBip link add ve_A type veth peer name ve_B\fP # Create veth pair +# \fBethtool \-S ve_A\fP # Discover interface index of peer +NIC statistics: + peer_ifindex: 16 +# \fBip link | grep \[aq]\[ha]16:\[aq]\fP # Look up interface +16: ve_B@ve_A: <BROADCAST,MULTICAST,M\-DOWN> mtu 1500 qdisc ... +.EE +.in +.SH "SEE ALSO" +.BR clone (2), +.BR network_namespaces (7), +.BR ip (8), +.BR ip\-link (8), +.BR ip\-netns (8) |