{"id":909,"date":"2014-10-28T09:33:50","date_gmt":"2014-10-28T08:33:50","guid":{"rendered":"http:\/\/elkano.org\/blog\/?p=909"},"modified":"2014-10-28T09:33:50","modified_gmt":"2014-10-28T08:33:50","slug":"openstack-ssh-timeout-gre-tunnels","status":"publish","type":"post","link":"https:\/\/elkano.org\/blog\/openstack-ssh-timeout-gre-tunnels\/","title":{"rendered":"OpenStack: ssh timeout with GRE tunnels"},"content":{"rendered":"<p>I configured my OpenStack installation and all went Ok. I used the Open vSwitch plugin with GRE tunnels and although I had ping connectivity, when I try to connect to instances through ssh I got a time out. The problem seemed to be in the tunnel MTU size. I had to lower the mtu size on instances to prevent packet fragmentation over GRE tunnel.<\/p>\n<p>Edit <strong> \/etc\/neutron\/dhcp_agent.ini<\/strong> file, add this line:<\/p>\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"raw\" data-enlighter-linenumbers=\"false\"># Override the default dnsmasq settings with this file\r\ndnsmasq_config_file = \/etc\/neutron\/dnsmasq\/dnsmasq-neutron.conf\r\n<\/pre>\n<p>&nbsp;<\/p>\n<p>Create file\u00a0\u00a0<strong>\/etc\/neutron\/dnsmasq\/dnsmasq-neutron.conf<\/strong> and add these values:<\/p>\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"raw\" data-enlighter-linenumbers=\"false\">dhcp-option-force=26,1400<\/pre>\n<p>&nbsp;<\/p>\n<p>Finally restart neutron server<\/p>\n<pre class=\"EnlighterJSRAW\" data-enlighter-language=\"raw\" data-enlighter-linenumbers=\"false\"># service neutron-server restart<\/pre>\n<p>&nbsp;<\/p>\n<p>References:<\/p>\n<p>http:\/\/docs.openstack.org\/admin-guide-cloud\/content\/openvswitch_plugin.html<\/p>\n","protected":false},"excerpt":{"rendered":"<p>I configured my OpenStack installation and all went Ok. I used the Open vSwitch plugin with GRE tunnels and although I had ping connectivity, when I try to connect to instances through ssh I got a time out. The problem seemed to be in the tunnel MTU size. I had to lower the mtu size [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[128,7],"tags":[129,130,149,96],"_links":{"self":[{"href":"https:\/\/elkano.org\/blog\/wp-json\/wp\/v2\/posts\/909"}],"collection":[{"href":"https:\/\/elkano.org\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/elkano.org\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/elkano.org\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/elkano.org\/blog\/wp-json\/wp\/v2\/comments?post=909"}],"version-history":[{"count":6,"href":"https:\/\/elkano.org\/blog\/wp-json\/wp\/v2\/posts\/909\/revisions"}],"predecessor-version":[{"id":915,"href":"https:\/\/elkano.org\/blog\/wp-json\/wp\/v2\/posts\/909\/revisions\/915"}],"wp:attachment":[{"href":"https:\/\/elkano.org\/blog\/wp-json\/wp\/v2\/media?parent=909"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/elkano.org\/blog\/wp-json\/wp\/v2\/categories?post=909"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/elkano.org\/blog\/wp-json\/wp\/v2\/tags?post=909"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}