/veth-example

veth-example

Environment

  • lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 18.04.5 LTS
Release:    18.04
Codename:   bionic

Example

  • ip netns add test
  • ip netns
test
  • ip link add veth0 type veth peer name veth1 netns test: create a pair and then assign veth1 into namespace test
  • ip addr show veth0: show it in the global namespace
130: veth0@if2: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether 8e:4c:e4:f8:df:aa brd ff:ff:ff:ff:ff:ff link-netnsid 15
  • ip netns exec test ip addr: run ip addr under the test network namespace.
1: lo: <LOOPBACK> mtu 65536 qdisc noop state DOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: veth1@if130: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether ca:83:85:f5:36:fe brd ff:ff:ff:ff:ff:ff link-netnsid 0
  • ip addr add 10.1.1.1/24 dev veth0 && ip addr show veth0
130: veth0@if2: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether 8e:4c:e4:f8:df:aa brd ff:ff:ff:ff:ff:ff link-netnsid 15
    inet 10.1.1.1/24 scope global veth0
       valid_lft forever preferred_lft forever
  • ip netns exec test ip addr add 10.1.1.2/24 dev veth1 && ip netns exec test ip addr show veth1
2: veth1@if130: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether ca:83:85:f5:36:fe brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 10.1.1.2/24 scope global veth1
       valid_lft forever preferred_lft forever
  • ip link set veth0 up
  • ip netns exec test ip link set veth1 up
  • ping -I 10.1.1.1 10.1.1.2
PING 10.1.1.2 (10.1.1.2) from 10.1.1.1 : 56(84) bytes of data.
64 bytes from 10.1.1.2: icmp_seq=1 ttl=64 time=0.060 ms
64 bytes from 10.1.1.2: icmp_seq=2 ttl=64 time=0.033 ms
64 bytes from 10.1.1.2: icmp_seq=3 ttl=64 time=0.033 ms

Troubleshooting

  • ip netns del test: delete the namespace test
  • ip link delete veth0: delete the interface veth0

References