{"action":"opened","issue":{"url":"https://api.github.com/repos/kubernetes/kubernetes/issues/17788","labels_url":"https://api.github.com/repos/kubernetes/kubernetes/issues/17788/labels{/name}","comments_url":"https://api.github.com/repos/kubernetes/kubernetes/issues/17788/comments","events_url":"https://api.github.com/repos/kubernetes/kubernetes/issues/17788/events","html_url":"https://github.com/kubernetes/kubernetes/issues/17788","id":118887943,"number":17788,"title":"Start ubuntu cluster in vagrant cannot customise flannel default interface in config-default.sh.","user":{"login":"tongda","id":653425,"avatar_url":"https://avatars.githubusercontent.com/u/653425?v=3","gravatar_id":"","url":"https://api.github.com/users/tongda","html_url":"https://github.com/tongda","followers_url":"https://api.github.com/users/tongda/followers","following_url":"https://api.github.com/users/tongda/following{/other_user}","gists_url":"https://api.github.com/users/tongda/gists{/gist_id}","starred_url":"https://api.github.com/users/tongda/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/tongda/subscriptions","organizations_url":"https://api.github.com/users/tongda/orgs","repos_url":"https://api.github.com/users/tongda/repos","events_url":"https://api.github.com/users/tongda/events{/privacy}","received_events_url":"https://api.github.com/users/tongda/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":0,"created_at":"2015-11-25T17:36:09Z","updated_at":"2015-11-25T17:36:09Z","closed_at":null,"body":"When running k8s cluster in vagrant and bootstrap it using cluster/ubuntu scripts, I found that pods cannot access each other using flannel ip. After digging into this problem, I found that it is because flannel would look for default interface after start up. Since the default interface (`eth0`, ip is `10.0.2.15` in my case) is a *nat* interface in vagrant VM, flannel will use `10.0.2.15` as external interface. However, the correct binding should be `eth1`, which is the hostonly network interface, so that I have to modify the `/etc/default/flanneld` like this:\r\n\r\n```\r\nFLANNEL_OPTS=\"-iface=eth1 --etcd-endpoints=http://172.28.128.12:4001\"\r\n```\r\n\r\nI think the `-iface` option should be configurable in config-default.sh."}}