{"id":414,"date":"2022-05-30T17:22:18","date_gmt":"2022-05-30T15:22:18","guid":{"rendered":"https:\/\/vpn.univ-fcomte.fr\/?p=414"},"modified":"2026-01-16T11:36:32","modified_gmt":"2026-01-16T09:36:32","slug":"ubuntu-20-04-et-non-resolution-de-nom-externe-une-fois-connecte-en-vpn","status":"publish","type":"post","link":"https:\/\/vpn.univ-fcomte.fr\/?p=414","title":{"rendered":"Ubuntu 22.04 et non r\u00e9solution de nom externe une fois connect\u00e9 en VPN"},"content":{"rendered":"\n<p>Avec la version 22.04, le fonctionnement de dnsmasq a chang\u00e9. Un client Ubuntu 20.04 connect\u00e9 au VPN de l&rsquo;UFC et voulant aller sur un site externe \u00e0 l&rsquo;UFC se retrouve bloqu\u00e9 car la r\u00e9solution de nom \u00e9choue.<\/p>\n\n\n\n<p><strong>Explication<\/strong><\/p>\n\n\n\n<p>Nous avons pu identifier le probl\u00e8me au niveau de dnsmasq, sans pour autant retrouver l&rsquo;explication de la diff\u00e9rence de fonctionnement.<\/p>\n\n\n\n<p>Sur les versions 18.04 et 20.04, le dnsmasq \u00e9tait interrog\u00e9 et lorsque celui-ci n&rsquo;avait pas de r\u00e9ponse (aucun cas n&rsquo;\u00e9tant trouv\u00e9 dans la configuration), il passait la main au DNS de base (le DNS de la Box ou de la connexion 4G).<\/p>\n\n\n\n<p>Avec la derni\u00e8re version (22.04), si dnsmasq est activ\u00e9, celui-ci ne passe plus la main au serveur de base. De fait, une r\u00e9solution sur un site non inclus dans la configuration \u00e9choue.<\/p>\n\n\n\n<p><strong>Correction<\/strong><\/p>\n\n\n\n<p>Pour corriger le probl\u00e8me, Jean-Michel Caricand \u00e0 eu l&rsquo;id\u00e9e d&rsquo;inclure de force un DNS de base toujours accessible.<\/p>\n\n\n\n<p>Il faut cr\u00e9er un nouveau fichier <code>\/etc\/NetworkManager\/dnsmasq.d\/00-use-dns-google.conf<\/code> :<\/p>\n\n\n\n<p><code>server=8.8.8.8<br>server=8.8.4.4<\/code><\/p>\n\n\n\n<p>La documentation en ligne pour Ubuntu contient cette correction.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Avec la version 22.04, le fonctionnement de dnsmasq a chang\u00e9. Un client Ubuntu 20.04 connect\u00e9 au VPN de l&rsquo;UFC et voulant aller sur un site externe \u00e0 l&rsquo;UFC se retrouve bloqu\u00e9 car la r\u00e9solution de nom \u00e9choue. Explication Nous avons pu identifier le probl\u00e8me au niveau de dnsmasq, sans pour autant retrouver l&rsquo;explication de la [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4,1],"tags":[182,183,172],"class_list":["post-414","post","type-post","status-publish","format-standard","hentry","category-informations-techniques","category-informations-utilisateurs","tag-22-04","tag-dnsmasq","tag-ubuntu"],"_links":{"self":[{"href":"https:\/\/vpn.univ-fcomte.fr\/index.php?rest_route=\/wp\/v2\/posts\/414","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/vpn.univ-fcomte.fr\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/vpn.univ-fcomte.fr\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/vpn.univ-fcomte.fr\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/vpn.univ-fcomte.fr\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=414"}],"version-history":[{"count":2,"href":"https:\/\/vpn.univ-fcomte.fr\/index.php?rest_route=\/wp\/v2\/posts\/414\/revisions"}],"predecessor-version":[{"id":530,"href":"https:\/\/vpn.univ-fcomte.fr\/index.php?rest_route=\/wp\/v2\/posts\/414\/revisions\/530"}],"wp:attachment":[{"href":"https:\/\/vpn.univ-fcomte.fr\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=414"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/vpn.univ-fcomte.fr\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=414"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vpn.univ-fcomte.fr\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=414"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}