{"id":8023,"date":"2025-12-29T23:59:29","date_gmt":"2025-12-29T18:29:29","guid":{"rendered":"https:\/\/www.suramya.com\/blog\/?p=8023"},"modified":"2025-12-30T00:23:20","modified_gmt":"2025-12-29T18:53:20","slug":"openvpn-not-working-for-websites-when-connected-over-airtel-xtreme-fibernet","status":"publish","type":"post","link":"https:\/\/www.suramya.com\/blog\/2025\/12\/openvpn-not-working-for-websites-when-connected-over-airtel-xtreme-fibernet\/","title":{"rendered":"OpenVPN Not working for websites when connected over Airtel Xtreme Fibernet"},"content":{"rendered":"<p>Over the past few weeks I have been having issues browsing websites when connected to OpenVPN connection on my Airtel Fibernet connection. The interesting thing was that the same settings\/vpn worked fine when I connected to my ACT connection instead of Airtel. So I knew it wasn&#8217;t an issue on the VPN side, it was something to do with how Airtel was configured and it was really annoying me. So, over the weekend I decided to spend some focused time to fix this issue and finally managed to fix the issue. <\/p>\n<p><strong>Symptoms:<\/strong><\/p>\n<ul>\n<li>The VPN Connection would connect without errors. <\/li>\n<li>No error messages in logs<\/li>\n<li>When trying to access websites, it would just wait for the website to respond. (Initially thought it was a SSL issue but hit the same issue with http)<\/li>\n<li>Putting the system in the DMZ didn&#8217;t work<\/li>\n<li>Manually configuring the Routes to match the Route when connected to ACT didn&#8217;t work either<\/li>\n<li>Traceroute worked fine though<\/li>\n<\/ul>\n<p>Curl in verbose mode would giving me the following and then it would just sit there waiting for a response:<\/p>\n<blockquote><p>suramya@StarKnight:~\/Media\/Downloads$ curl -vvv www.google.com<br \/>\n02:43:17.786482 [0-x] == Info: [READ] client_reset, clear readers<br \/>\n02:43:18.370318 [0-0] == Info: Host www.google.com:80 was resolved.<br \/>\n02:43:18.370467 [0-0] == Info: IPv6: 2607:f8b0:4005:80d::2004<br \/>\n02:43:18.370566 [0-0] == Info: IPv4: 142.250.189.164<br \/>\n02:43:18.370624 [0-0] == Info: [SETUP] added<br \/>\n02:43:18.370723 [0-0] == Info:   Trying [2607:f8b0:4005:80d::2004]:80&#8230;<br \/>\n02:43:18.370951 [0-0] == Info: Immediate connect fail for 2607:f8b0:4005:80d::2004: Network is unreachable<br \/>\n02:43:18.371175 [0-0] == Info:   Trying 142.250.189.164:80&#8230;<br \/>\n02:43:18.371332 [0-0] == Info: [SETUP] Curl_conn_connect(block=0) -> 0, done=0<br \/>\n02:43:18.544635 [0-0] == Info: [SETUP] Curl_conn_connect(block=0) -> 0, done=0<br \/>\n02:43:18.570870 [0-0] == Info: [SETUP] Curl_conn_connect(block=0) -> 0, done=0<br \/>\n02:43:18.699887 [0-0] == Info: [SETUP] Curl_conn_connect(block=0) -> 0, done=1<br \/>\n02:43:18.700062 [0-0] == Info: Connected to www.google.com (142.250.189.164) port 80<br \/>\n02:43:18.700228 [0-0] == Info: using HTTP\/1.x<br \/>\n02:43:18.700338 [0-0] => Send header, 82 bytes (0x52)<br \/>\n0000: GET \/ HTTP\/1.1<br \/>\n0010: Host: www.google.com<br \/>\n0026: User-Agent: curl\/8.13.0-rc2<br \/>\n0043: Accept: *\/*<br \/>\n0050:<br \/>\n02:43:18.700663 [0-0] == Info: Request completely sent off<\/p><\/blockquote>\n<p>Then suddenly just to try something different I tried accessing one of my servers over SSH and surprisingly that worked without issues (The connection was a bit slow, but it worked). That showed me that the issue was only for sites over http\/https. <\/p>\n<p>I searched the web for solutions and found the following site <a href='https:\/\/forums.openvpn.net\/viewtopic.php?t=25039'>Setting correct MTU<\/a> where they were troubleshooting a similar issue. The site suggested adding the following lines to the Client Configuration and I thought I might as well give it a try since nothing else had worked. <\/p>\n<pre class='code'> tun-mtu 1492\r\nmssfix 1400<\/pre>\n<p>I added the lines, restarted the connection and viola all sites started loading even when connected over the VPN. (Yay!) Turns out Airtel needs a higher MTU value than the default for the VPN to work. <\/p>\n<p>&#8211; Suramya<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Over the past few weeks I have been having issues browsing websites when connected to OpenVPN connection on my Airtel Fibernet connection. The interesting thing was that the same settings\/vpn worked fine when I connected to my ACT connection instead of Airtel. So I knew it wasn&#8217;t an issue on the VPN side, it was [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"activitypub_content_warning":"","activitypub_content_visibility":"","activitypub_max_image_attachments":3,"activitypub_interaction_policy_quote":"","activitypub_status":"federated","footnotes":""},"categories":[18,9,24,13,2],"tags":[],"class_list":["post-8023","post","type-post","status-publish","format-standard","hentry","category-computer-software","category-computer-hintstips","category-knowledgebase","category-linuxunix-related","category-techie-stuff"],"_links":{"self":[{"href":"https:\/\/www.suramya.com\/blog\/wp-json\/wp\/v2\/posts\/8023","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.suramya.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.suramya.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.suramya.com\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.suramya.com\/blog\/wp-json\/wp\/v2\/comments?post=8023"}],"version-history":[{"count":4,"href":"https:\/\/www.suramya.com\/blog\/wp-json\/wp\/v2\/posts\/8023\/revisions"}],"predecessor-version":[{"id":8053,"href":"https:\/\/www.suramya.com\/blog\/wp-json\/wp\/v2\/posts\/8023\/revisions\/8053"}],"wp:attachment":[{"href":"https:\/\/www.suramya.com\/blog\/wp-json\/wp\/v2\/media?parent=8023"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.suramya.com\/blog\/wp-json\/wp\/v2\/categories?post=8023"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.suramya.com\/blog\/wp-json\/wp\/v2\/tags?post=8023"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}