{"action":"opened","issue":{"url":"https://api.github.com/repos/rancher/rancher/issues/3528","repository_url":"https://api.github.com/repos/rancher/rancher","labels_url":"https://api.github.com/repos/rancher/rancher/issues/3528/labels{/name}","comments_url":"https://api.github.com/repos/rancher/rancher/issues/3528/comments","events_url":"https://api.github.com/repos/rancher/rancher/issues/3528/events","html_url":"https://github.com/rancher/rancher/issues/3528","id":131473673,"number":3528,"title":"Network agent keeps flipping from gcm=false to gcm=true","user":{"login":"bhinkle-work","id":16246389,"avatar_url":"https://avatars.githubusercontent.com/u/16246389?v=3","gravatar_id":"","url":"https://api.github.com/users/bhinkle-work","html_url":"https://github.com/bhinkle-work","followers_url":"https://api.github.com/users/bhinkle-work/followers","following_url":"https://api.github.com/users/bhinkle-work/following{/other_user}","gists_url":"https://api.github.com/users/bhinkle-work/gists{/gist_id}","starred_url":"https://api.github.com/users/bhinkle-work/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/bhinkle-work/subscriptions","organizations_url":"https://api.github.com/users/bhinkle-work/orgs","repos_url":"https://api.github.com/users/bhinkle-work/repos","events_url":"https://api.github.com/users/bhinkle-work/events{/privacy}","received_events_url":"https://api.github.com/users/bhinkle-work/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":0,"created_at":"2016-02-04T21:06:09Z","updated_at":"2016-02-04T21:06:09Z","closed_at":null,"body":"We upgraded from Rancher v0.51.0 to v0.56.1 and are experiencing a problem with managed networking. We have multiple environments with CentOS 7.0 hosts and are using the managed network for our application stacks.\r\n\r\nThe behavior we are observing is that, unpredictably, a network agent on one of the hosts will start rancher-net with **gcm=true** instead of **gcm=false** or vice versa (i.e. there is a mismatch on one host versus the others). This prevents managed networking communication between hosts. Generally a restart of the network agent will cause it to pick up the same setting as the rest of the environment - sometimes we have to restart it on the one-off host, sometimes we have to restart it on all the others.\r\n\r\nI'm concerned, because:\r\n- this is happening unpredictably\r\n- gcm=false seems more common and yet  @deniseschannon believes (per #3479) that gcm=true is the ideal case for centos and ubuntu\r\n- the network agent gets recreated every time we deploy a stack with load balancers, so it hurts us frequently\r\n- host reboots and container deletions have not solved this problem\r\n\r\nWhat else should I be looking into?"}}