{"id":2533,"date":"2011-09-06T09:14:46","date_gmt":"2011-09-06T01:14:46","guid":{"rendered":"http:\/\/staff.ie.cuhk.edu.hk\/~sfluk\/wordpress\/?p=2533"},"modified":"2011-09-13T00:43:50","modified_gmt":"2011-09-12T16:43:50","slug":"l2tp-over-ipsec-on-linux-and-ubuntu","status":"publish","type":"post","link":"https:\/\/staff.ie.cuhk.edu.hk\/~sfluk\/wordpress\/?p=2533","title":{"rendered":"L2TP over IPsec client on Linux and Ubuntu"},"content":{"rendered":"<p>Finally, a tool which can provide the required UI and generate the suitable configuration for xl2tp, ppp and openswan to provide the L2TP over IPsec on Linux with only a few clicks. I have tested it, it works without problem with my dept ASA applicance and CUHK&#8217;s VPN. The only minor problem is that you better to do a reboot after adding VPN connection, otherwise it will never works!! Moreover, after the disconnection, the assigned DNS servers cannot be resumed to the original one.<\/p>\n<p><a href=\"https:\/\/launchpad.net\/l2tp-ipsec-vpn\">https:\/\/launchpad.net\/l2tp-ipsec-vpn<\/a><\/p>\n<p>Ubuntu 11.04 installation procedures :<\/p>\n<p><code>sudo apt-add-repository ppa:werner-jaeger\/ppa-werner-vpn<br \/>\nsudo apt-get update<br \/>\nsudo apt-get install l2tp-ipsec-vpn<br \/>\ngsettings set com.canonical.Unity.Panel systray-whitelist \"['all']\"<br \/>\nsudo shutdown -r now <\/code><\/p>\n<p><a href=\"http:\/\/staff.ie.cuhk.edu.hk\/~sfluk\/wordpress\/wp-content\/uploads\/2011\/09\/l2tp1.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-2539\" title=\"l2tp1\" src=\"http:\/\/staff.ie.cuhk.edu.hk\/~sfluk\/wordpress\/wp-content\/uploads\/2011\/09\/l2tp1.png\" alt=\"\" width=\"450\" height=\"479\" srcset=\"https:\/\/staff.ie.cuhk.edu.hk\/~sfluk\/wordpress\/wp-content\/uploads\/2011\/09\/l2tp1.png 450w, https:\/\/staff.ie.cuhk.edu.hk\/~sfluk\/wordpress\/wp-content\/uploads\/2011\/09\/l2tp1-281x300.png 281w, https:\/\/staff.ie.cuhk.edu.hk\/~sfluk\/wordpress\/wp-content\/uploads\/2011\/09\/l2tp1-140x150.png 140w, https:\/\/staff.ie.cuhk.edu.hk\/~sfluk\/wordpress\/wp-content\/uploads\/2011\/09\/l2tp1-400x425.png 400w\" sizes=\"auto, (max-width: 450px) 100vw, 450px\" \/><\/a><\/p>\n<p><a href=\"http:\/\/staff.ie.cuhk.edu.hk\/~sfluk\/wordpress\/wp-content\/uploads\/2011\/09\/l2tp2.png\"><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-2540\" title=\"l2tp2\" src=\"http:\/\/staff.ie.cuhk.edu.hk\/~sfluk\/wordpress\/wp-content\/uploads\/2011\/09\/l2tp2.png\" alt=\"\" width=\"443\" height=\"480\" srcset=\"https:\/\/staff.ie.cuhk.edu.hk\/~sfluk\/wordpress\/wp-content\/uploads\/2011\/09\/l2tp2.png 443w, https:\/\/staff.ie.cuhk.edu.hk\/~sfluk\/wordpress\/wp-content\/uploads\/2011\/09\/l2tp2-276x300.png 276w, https:\/\/staff.ie.cuhk.edu.hk\/~sfluk\/wordpress\/wp-content\/uploads\/2011\/09\/l2tp2-138x150.png 138w, https:\/\/staff.ie.cuhk.edu.hk\/~sfluk\/wordpress\/wp-content\/uploads\/2011\/09\/l2tp2-400x433.png 400w\" sizes=\"auto, (max-width: 443px) 100vw, 443px\" \/><\/a><\/p>\n<p><a href=\"http:\/\/wiki.l2tpipsecvpn.tuxfamily.org\/wiki\/index.php?title=Main_Page#L2TP_over_IPsec_VPN_Manager_User_Guide\">http:\/\/wiki.l2tpipsecvpn.tuxfamily.org\/wiki\/index.php?title=Main_Page#L2TP_over_IPsec_VPN_Manager_User_Guide<\/a><\/p>\n<p><a href=\"http:\/\/www.tuvpn.com\/en\/tutorials\/l2tp-ipsec-ubuntu-11-04-natty-narwhal#step-0\">http:\/\/www.tuvpn.com\/en\/tutorials\/l2tp-ipsec-ubuntu-11-04-natty-narwhal#step-0<\/a><\/p>\n<p>PS: After testing\u00a0 the VPN connections to my dept. VPN for a while, I found a strange problem : All the connection worked without problem at the very beginning, say ssh, http, etc. However, whenever I needed to submit a form via one of my testing web server. The connection hanged and the form could never been saved. I have puzzled for this problem for weeks. At last, baesd on my past experience of configuration of modem dialup, I changed the mtu of the ppp connection from default 1500 to 1000 since sometimes you may need to adjust the mtu during dialup over WAN and everything worked like a magic!!<\/p>\n<p>For my conflagration at home, I need to add <strong>mtu 1000<\/strong> at the end of the file \/etc\/ppp\/IEVPN.options.xl2tpd and at my office LAN, I don&#8217;t need to add this to make the stuff works.<\/p>\n<p>Extra:<\/p>\n<p><a href=\"http:\/\/riobard.com\/blog\/2010-04-30-l2tp-over-ipsec-ubuntu\/\">http:\/\/riobard.com\/blog\/2010-04-30-l2tp-over-ipsec-ubuntu\/<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Finally, a tool which can provide the required UI and generate the suitable configuration for xl2tp, ppp and openswan to provide the L2TP over IPsec on Linux with only a few clicks. I have tested it, it works without problem with my dept ASA applicance and CUHK&#8217;s VPN. The only minor problem is that you [&#8230;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"ngg_post_thumbnail":0,"footnotes":""},"categories":[3],"tags":[56],"class_list":["post-2533","post","type-post","status-publish","format-standard","hentry","category-computer","tag-ubuntu","odd"],"_links":{"self":[{"href":"https:\/\/staff.ie.cuhk.edu.hk\/~sfluk\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/2533","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/staff.ie.cuhk.edu.hk\/~sfluk\/wordpress\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/staff.ie.cuhk.edu.hk\/~sfluk\/wordpress\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/staff.ie.cuhk.edu.hk\/~sfluk\/wordpress\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/staff.ie.cuhk.edu.hk\/~sfluk\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=2533"}],"version-history":[{"count":13,"href":"https:\/\/staff.ie.cuhk.edu.hk\/~sfluk\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/2533\/revisions"}],"predecessor-version":[{"id":2550,"href":"https:\/\/staff.ie.cuhk.edu.hk\/~sfluk\/wordpress\/index.php?rest_route=\/wp\/v2\/posts\/2533\/revisions\/2550"}],"wp:attachment":[{"href":"https:\/\/staff.ie.cuhk.edu.hk\/~sfluk\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=2533"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/staff.ie.cuhk.edu.hk\/~sfluk\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=2533"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/staff.ie.cuhk.edu.hk\/~sfluk\/wordpress\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=2533"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}