3 Flannel is a network fabric for containers, designed for Kubernetes
5 **Warning:** You may encounter this [bug](https://github.com/coreos/flannel/pull/1282) with `VXLAN` backend, while waiting on a newer Flannel version the current workaround (`ethtool --offload flannel.1 rx off tx off`) is showcase in kubespray [networking test](tests/testcases/040_check-network-adv.yml:31).
7 ## Verifying flannel install
9 * Flannel configuration file should have been created there
12 cat /run/flannel/subnet.env
13 FLANNEL_NETWORK=10.233.0.0/18
14 FLANNEL_SUBNET=10.233.16.1/24
19 * Check if the network interface has been created
22 ip a show dev flannel.1
23 4: flannel.1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1450 qdisc noqueue state UNKNOWN group default
24 link/ether e2:f3:a7:0f:bf:cb brd ff:ff:ff:ff:ff:ff
25 inet 10.233.16.0/18 scope global flannel.1
26 valid_lft forever preferred_lft forever
27 inet6 fe80::e0f3:a7ff:fe0f:bfcb/64 scope link
28 valid_lft forever preferred_lft forever
31 * Try to run a container and check its ip address
34 kubectl run test --image=busybox --command -- tail -f /dev/null
35 replicationcontroller "test" created
37 kubectl describe po test-34ozs | grep ^IP
42 kubectl exec test-34ozs -- ip a show dev eth0
43 8: eth0@if9: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1450 qdisc noqueue
44 link/ether 02:42:0a:e9:2b:03 brd ff:ff:ff:ff:ff:ff
45 inet 10.233.16.2/24 scope global eth0
46 valid_lft forever preferred_lft forever
47 inet6 fe80::42:aff:fee9:2b03/64 scope link tentative flags 08
48 valid_lft forever preferred_lft forever