{"id":52508,"date":"2025-09-30T12:09:53","date_gmt":"2025-09-30T09:09:53","guid":{"rendered":"https:\/\/infinitydomainhosting.com\/kb\/common-proxy-issues-in-networking-and-fixes\/"},"modified":"2025-09-30T12:09:53","modified_gmt":"2025-09-30T09:09:53","slug":"common-proxy-issues-in-networking-and-fixes","status":"publish","type":"post","link":"https:\/\/infinitydomainhosting.com\/kb\/common-proxy-issues-in-networking-and-fixes\/","title":{"rendered":"Common Proxy Issues in Networking and Fixes"},"content":{"rendered":"<p><\/p>\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_80 counter-hierarchy ez-toc-counter ez-toc-grey ez-toc-container-direction\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\" style=\"cursor:inherit\">Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a href=\"#\" class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" aria-label=\"Toggle Table of Content\"><span class=\"ez-toc-js-icon-con\"><span class=\"\"><span class=\"eztoc-hide\" style=\"display:none;\">Toggle<\/span><span class=\"ez-toc-icon-toggle-span\"><svg style=\"fill: #999;color:#999\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" class=\"list-377408\" width=\"20px\" height=\"20px\" viewBox=\"0 0 24 24\" fill=\"none\"><path d=\"M6 6H4v2h2V6zm14 0H8v2h12V6zM4 11h2v2H4v-2zm16 0H8v2h12v-2zM4 16h2v2H4v-2zm16 0H8v2h12v-2z\" fill=\"currentColor\"><\/path><\/svg><svg style=\"fill: #999;color:#999\" class=\"arrow-unsorted-368013\" xmlns=\"http:\/\/www.w3.org\/2000\/svg\" width=\"10px\" height=\"10px\" viewBox=\"0 0 24 24\" version=\"1.2\" baseProfile=\"tiny\"><path d=\"M18.2 9.3l-6.2-6.3-6.2 6.3c-.2.2-.3.4-.3.7s.1.5.3.7c.2.2.4.3.7.3h11c.3 0 .5-.1.7-.3.2-.2.3-.5.3-.7s-.1-.5-.3-.7zM5.8 14.7l6.2 6.3 6.2-6.3c.2-.2.3-.5.3-.7s-.1-.5-.3-.7c-.2-.2-.4-.3-.7-.3h-11c-.3 0-.5.1-.7.3-.2.2-.3.5-.3.7s.1.5.3.7z\"\/><\/svg><\/span><\/span><\/span><\/a><\/span><\/div>\n<nav><ul class='ez-toc-list ez-toc-list-level-1 ' ><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/infinitydomainhosting.com\/kb\/common-proxy-issues-in-networking-and-fixes\/#Quick_orientation\" >Quick orientation<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/infinitydomainhosting.com\/kb\/common-proxy-issues-in-networking-and-fixes\/#How_to_approach_a_proxy_problem\" >How to approach a proxy problem<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-3\" href=\"https:\/\/infinitydomainhosting.com\/kb\/common-proxy-issues-in-networking-and-fixes\/#Common_issues_and_fixes\" >Common issues and fixes<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-4\" href=\"https:\/\/infinitydomainhosting.com\/kb\/common-proxy-issues-in-networking-and-fixes\/#1_No_connection_%E2%80%9CProxy_server_not_responding%E2%80%9D\" >1) No connection \/ \u201cProxy server not responding\u201d<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-5\" href=\"https:\/\/infinitydomainhosting.com\/kb\/common-proxy-issues-in-networking-and-fixes\/#2_Authentication_problems_HTTP_407\" >2) Authentication problems (HTTP 407)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-6\" href=\"https:\/\/infinitydomainhosting.com\/kb\/common-proxy-issues-in-networking-and-fixes\/#3_ssltls_and_certificate_warnings\" >3) ssl\/tls and certificate warnings<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-7\" href=\"https:\/\/infinitydomainhosting.com\/kb\/common-proxy-issues-in-networking-and-fixes\/#4_Slow_browsing_or_high_latency\" >4) Slow browsing or high latency<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-8\" href=\"https:\/\/infinitydomainhosting.com\/kb\/common-proxy-issues-in-networking-and-fixes\/#5_HTTP_errors_from_the_proxy_502_503_504\" >5) HTTP errors from the proxy (502, 503, 504)<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-9\" href=\"https:\/\/infinitydomainhosting.com\/kb\/common-proxy-issues-in-networking-and-fixes\/#6_PACWPAD_script_problems\" >6) PAC\/WPAD script problems<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-10\" href=\"https:\/\/infinitydomainhosting.com\/kb\/common-proxy-issues-in-networking-and-fixes\/#7_Transparent_proxy_and_SSL_interception_friction\" >7) Transparent proxy and SSL interception friction<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-11\" href=\"https:\/\/infinitydomainhosting.com\/kb\/common-proxy-issues-in-networking-and-fixes\/#8_DNS_problems_and_leaks\" >8) DNS problems and leaks<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-12\" href=\"https:\/\/infinitydomainhosting.com\/kb\/common-proxy-issues-in-networking-and-fixes\/#9_Application-specific_proxy_issues\" >9) Application-specific proxy issues<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-13\" href=\"https:\/\/infinitydomainhosting.com\/kb\/common-proxy-issues-in-networking-and-fixes\/#Useful_commands_and_checks\" >Useful commands and checks<\/a><ul class='ez-toc-list-level-3' ><li class='ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-14\" href=\"https:\/\/infinitydomainhosting.com\/kb\/common-proxy-issues-in-networking-and-fixes\/#Linux_macOS\" >Linux \/ macOS<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-15\" href=\"https:\/\/infinitydomainhosting.com\/kb\/common-proxy-issues-in-networking-and-fixes\/#Windows\" >Windows<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-3'><a class=\"ez-toc-link ez-toc-heading-16\" href=\"https:\/\/infinitydomainhosting.com\/kb\/common-proxy-issues-in-networking-and-fixes\/#Proxy_server_checks\" >Proxy server checks<\/a><\/li><\/ul><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-17\" href=\"https:\/\/infinitydomainhosting.com\/kb\/common-proxy-issues-in-networking-and-fixes\/#Logging_and_monitoring\" >Logging and monitoring<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-18\" href=\"https:\/\/infinitydomainhosting.com\/kb\/common-proxy-issues-in-networking-and-fixes\/#Checklist_quick_fixes_to_try_now\" >Checklist: quick fixes to try now<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-19\" href=\"https:\/\/infinitydomainhosting.com\/kb\/common-proxy-issues-in-networking-and-fixes\/#When_to_escalate\" >When to escalate<\/a><\/li><li class='ez-toc-page-1 ez-toc-heading-level-2'><a class=\"ez-toc-link ez-toc-heading-20\" href=\"https:\/\/infinitydomainhosting.com\/kb\/common-proxy-issues-in-networking-and-fixes\/#Summary\" >Summary<\/a><\/li><\/ul><\/nav><\/div>\n<h2><span class=\"ez-toc-section\" id=\"Quick_orientation\"><\/span>Quick orientation<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><\/p>\n<p>If <a href=\"https:\/\/infinitydomainhosting.com\/kb\/how-to-configure-2fa-step-by-step\/\">a<\/a> proxy is between your client and the internet, any hiccup can look like a network outage. Below are common proxy issues you&#8217;ll see and straightforward ways to diagnose and fix them. Read the short troubleshooting steps first, then use the command examples and tips for deeper investigation.<\/p>\n<p><\/p>\n<h2><span class=\"ez-toc-section\" id=\"How_to_approach_a_proxy_problem\"><\/span>How to approach a proxy problem<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><\/p>\n<ul><\/p>\n<li>Check whether the problem is client-specific, network-wide, or server-side.<\/li>\n<p><\/p>\n<li>Gather symptoms: browser errors, <a href=\"https:\/\/www.hostinger.com\/tutorials\/http-status-codes\" target=\"_blank\" rel=\"noopener\">http status codes<\/a>, app logs, timestamps.<\/li>\n<p><\/p>\n<li>Confirm simple things first: correct proxy address\/port, <a href=\"https:\/\/infinitydomainhosting.com\/index.php?rp=\/knowledgebase\/128\/How-to-manage-your-DNS-settings-for-your-domain.html\">DNS<\/a> resolution, credentials.<\/li>\n<p><\/p>\n<li><a href=\"https:\/\/support.hostinger.com\/en\/articles\/2152545-how-to-inspect-website-elements-in-your-browser\" target=\"_blank\" rel=\"noopener\">inspect<\/a> proxy logs and run connectivity checks from both client and proxy <a href=\"https:\/\/www.a2hosting.com\/\" target=\"_blank\" rel=\"noopener\">host<\/a>.<\/li>\n<p>\n<\/ul>\n<p><\/p>\n<h2><span class=\"ez-toc-section\" id=\"Common_issues_and_fixes\"><\/span>Common issues and fixes<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><\/p>\n<h3><span class=\"ez-toc-section\" id=\"1_No_connection_%E2%80%9CProxy_server_not_responding%E2%80%9D\"><\/span>1) No connection \/ \u201cProxy server not responding\u201d<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><\/p>\n<p>Symptoms: browser times out, no response, connection refused.<\/p>\n<p><\/p>\n<ul><\/p>\n<li>Causes: wrong <a href=\"https:\/\/www.a2hosting.com\/\" target=\"_blank\" rel=\"noopener\">host<\/a> or port, proxy process down, firewall blocking, <a href=\"https:\/\/www.hostinger.com\/tutorials\/what-is-dns\" target=\"_blank\" rel=\"noopener\">dns<\/a> problem.<\/li>\n<p><\/p>\n<li>Fixes:\n<ul><\/p>\n<li>Ping and <a href=\"https:\/\/www.hostinger.com\/tutorials\/traceroute-command\" target=\"_blank\" rel=\"noopener\">traceroute<\/a> to the proxy host to confirm network path.<\/li>\n<p><\/p>\n<li>Check port with telnet, nc or <a href=\"https:\/\/www.hostinger.com\/tutorials\/curl-command-with-examples-linux\/\" target=\"_blank\" rel=\"noopener\">curl<\/a>:\n<pre><code>telnet proxy.example.com 3128<br \/>\n# or<br \/>\nnc -vz proxy.example.com 3128<br \/>\n# or try a proxied request<br \/>\ncurl -x  <\/code><\/pre>\n<p>\n      <\/li>\n<p><\/p>\n<li>Confirm proxy service is running on the server (systemctl, process list) and check firewall rules (iptables, nftables, <a href=\"https:\/\/hostadvice.com\/how-to\/web-hosting\/ubuntu\/how-to-configure-firewall-with-ufw-on-ubuntu-18\/\" target=\"_blank\" rel=\"noopener\">ufw<\/a>, security groups).<\/li>\n<p><\/p>\n<li>If DNS fails, use the proxy\u2019s IP instead of <a href=\"https:\/\/hostadvice.com\/blog\/domains\/difference-between-hostname-and-domain-name\/\" target=\"_blank\" rel=\"noopener\">hostname<\/a> or fix the DNS server entries.<\/li>\n<p>\n    <\/ul>\n<p>\n  <\/li>\n<p>\n<\/ul>\n<p><\/p>\n<h3><span class=\"ez-toc-section\" id=\"2_Authentication_problems_HTTP_407\"><\/span>2) Authentication problems (HTTP 407)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><\/p>\n<p>Symptoms: browser repeatedly prompts for credentials, 407 errors in logs.<\/p>\n<p><\/p>\n<ul><\/p>\n<li>Causes: bad username\/password, unsupported auth type (NTLM\/Kerberos mismatch), stale cache of credentials.<\/li>\n<p><\/p>\n<li>Fixes:\n<ul><\/p>\n<li>Clear saved credentials in the browser and re-enter them.<\/li>\n<p><\/p>\n<li>Verify server and client agree on auth mechanisms (basic, digest, NTLM, Kerberos). If NTLM is required, standard basic auth won\u2019t work.<\/li>\n<p><\/p>\n<li>On <a href=\"https:\/\/www.hostinger.com\/tutorials\/linux-commands\" target=\"_blank\" rel=\"noopener\">linux<\/a>\/<a href=\"https:\/\/www.hostinger.com\/tutorials\/what-is-cli\" target=\"_blank\" rel=\"noopener\">cli<\/a> apps, set credentials in the proxy <a href=\"https:\/\/www.hostinger.com\/tutorials\/what-is-a-url\" target=\"_blank\" rel=\"noopener\">url<\/a> or use a helper (for NTLM: cntlm or ntlm_auth). Example:\n<pre><code>export http_proxy=\"<\/code><\/pre>\n<p>\n      <\/li>\n<p><\/p>\n<li>Check the proxy audit\/logs to see why it rejects authentication and adjust <a href=\"https:\/\/support.hostinger.com\/en\/articles\/1583424-what-are-the-differences-between-subdomain-parked-domain-and-add-on-domain\" target=\"_blank\" rel=\"noopener\">domain and<\/a> SPN settings for Kerberos.<\/li>\n<p>\n    <\/ul>\n<p>\n  <\/li>\n<p>\n<\/ul>\n<p><\/p>\n<h3><span class=\"ez-toc-section\" id=\"3_ssltls_and_certificate_warnings\"><\/span>3) <a href=\"https:\/\/www.hostinger.com\/tutorials\/what-is-ssl\" target=\"_blank\" rel=\"noopener\">ssl<\/a>\/<a href=\"https:\/\/www.hostinger.com\/tutorials\/what-is-tls\" target=\"_blank\" rel=\"noopener\">tls<\/a> and certificate warnings<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><\/p>\n<p>Symptoms: certificate errors in browsers, TLS handshake failures, mixed content warnings.<\/p>\n<p><\/p>\n<ul><\/p>\n<li>Causes: corporate SSL interception (TLS bump), expired or missing CA certificate, wrong hostname in certificate.<\/li>\n<p><\/p>\n<li>Fixes:\n<ul><\/p>\n<li>Determine whether the proxy performs SSL inspection. If it does, install the proxy&#8217;s CA certificate into the client\u2019s trusted store (OS, browser, Java keystore as needed).<\/li>\n<p><\/p>\n<li>Check certificate dates and hostnames. Replace or reissue certificates if expired or misconfigured.<\/li>\n<p><\/p>\n<li>For apps that do certificate pinning, configure them to trust the inspecting CA or bypass inspection for those <a href=\"https:\/\/www.hostinger.com\/domain-name-search\" target=\"_blank\" rel=\"noopener\">domains<\/a>.<\/li>\n<p>\n    <\/ul>\n<p>\n  <\/li>\n<p>\n<\/ul>\n<p><\/p>\n<h3><span class=\"ez-toc-section\" id=\"4_Slow_browsing_or_high_latency\"><\/span>4) Slow browsing or high <a href=\"https:\/\/www.hostinger.com\/tutorials\/what-is-network-latency\" target=\"_blank\" rel=\"noopener\">latency<\/a><span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><\/p>\n<p>Symptoms: pages load slowly, timeouts under load, proxy CPU or memory high.<\/p>\n<p><\/p>\n<ul><\/p>\n<li>Causes: overloaded proxy, suboptimal <a href=\"https:\/\/infinitydomainhosting.com\/kb\/understanding-website-caching-and-website-performance-optimization\/\">caching<\/a>, network congestion, DNS delays.<\/li>\n<p><\/p>\n<li>Fixes:\n<ul><\/p>\n<li>Check proxy resource usage and logs. Scale the proxy or tune worker threads and connection limits.<\/li>\n<p><\/p>\n<li>Inspect cache hit ratio and TTLs; tune cache policies or clear stale objects.<\/li>\n<p><\/p>\n<li>Measure DNS resolution times and consider local <a href=\"https:\/\/www.a2hosting.com\/kb\/getting-started-guide\/internet-and-networking\/clearing-the-dns-cache-on-your-computer\/\" target=\"_blank\" rel=\"noopener\">dns caching<\/a> or faster resolvers.<\/li>\n<p><\/p>\n<li>Temporarily bypass the proxy to see if the problem is with the proxy or the network beyond it.<\/li>\n<p>\n    <\/ul>\n<p>\n  <\/li>\n<p>\n<\/ul>\n<p><\/p>\n<h3><span class=\"ez-toc-section\" id=\"5_HTTP_errors_from_the_proxy_502_503_504\"><\/span>5) HTTP errors from the proxy (502, 503, 504)<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><\/p>\n<p>Symptoms: gateway errors returned by the proxy for certain requests.<\/p>\n<p><\/p>\n<ul><\/p>\n<li>Causes: upstream server unavailable, proxy timeout, misconfigured backend, misrouted requests.<\/li>\n<p><\/p>\n<li>Fixes:\n<ul><\/p>\n<li>Confirm upstream servers are reachable and healthy.<\/li>\n<p><\/p>\n<li>Adjust proxy timeout and retry settings if legitimate upstream latency exists.<\/li>\n<p><\/p>\n<li>Check proxy routing rules and any load-balancer settings that might direct traffic incorrectly.<\/li>\n<p>\n    <\/ul>\n<p>\n  <\/li>\n<p>\n<\/ul>\n<p><\/p>\n<h3><span class=\"ez-toc-section\" id=\"6_PACWPAD_script_problems\"><\/span>6) PAC\/WPAD script problems<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><\/p>\n<p>Symptoms: some clients use wrong proxy, automatic configuration fails, inconsistent behavior across devices.<\/p>\n<p><\/p>\n<ul><\/p>\n<li>Causes: syntax errors in PAC file, incorrect MIME type, caching of old PAC files, wrong WPAD DNS\/DHCP records.<\/li>\n<p><\/p>\n<li>Fixes:\n<ul><\/p>\n<li>Validate the PAC file with a linter or by running it through test inputs.<\/li>\n<p><\/p>\n<li>Serve the PAC file with the correct MIME type (application\/x-ns-proxy-autoconfig).<\/li>\n<p><\/p>\n<li><a href=\"https:\/\/www.hostinger.com\/tutorials\/clear-browser-cache\" target=\"_blank\" rel=\"noopener\">clear browser cache<\/a> and DHCP\/DNS entries used for WPAD. Confirm WPAD host names are correct and reachable.<\/li>\n<p>\n    <\/ul>\n<p>\n  <\/li>\n<p>\n<\/ul>\n<p><\/p>\n<h3><span class=\"ez-toc-section\" id=\"7_Transparent_proxy_and_SSL_interception_friction\"><\/span>7) Transparent proxy and SSL interception friction<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><\/p>\n<p>Symptoms: local services fail, TLS handshake errors, double interception.<\/p>\n<p><\/p>\n<ul><\/p>\n<li>Causes: interception applied transparently without client awareness, incorrect routing, conflicts with NAT.<\/li>\n<p><\/p>\n<li>Fixes:\n<ul><\/p>\n<li>Ensure transparent interception rules are precise and bypass local addresses and services that must not be intercepted.<\/li>\n<p><\/p>\n<li>For TLS, prefer explicit proxying for sites requiring end-to-end certificates or configure split-tunnel policies.<\/li>\n<p><\/p>\n<li>Check iptables\/TProxy or firewall rules and remove unintended redirections.<\/li>\n<p>\n    <\/ul>\n<p>\n  <\/li>\n<p>\n<\/ul>\n<p><\/p>\n<h3><span class=\"ez-toc-section\" id=\"8_DNS_problems_and_leaks\"><\/span>8) DNS problems and leaks<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><\/p>\n<p>Symptoms: wrong site resolution, requests going directly to internet DNS, location-based restrictions leak.<\/p>\n<p><!--KB_CAT_BLOCK--><\/p>\n<figure class=\"kb-cat-placeholder\" style=\"margin:1.75rem 0;display:block;\">\n<div class=\"kb-cat-wrap\" style=\"position:relative; overflow:hidden; border-radius:12px; box-shadow:0 10px 36px rgba(0,0,0,0.14);\"><img src=\"https:\/\/infinitydomainhosting.com\/kb\/assets\/img\/cat-default.webp\" alt=\"Common Proxy Issues in Networking and Fixes\" loading=\"lazy\" decoding=\"async\" style=\"max-width:100%;height:auto;display:block;border-radius:12px;box-shadow:0 8px 28px rgba(0,0,0,0.12);\" \/><\/p>\n<div class=\"kb-cat-gradient\" style=\"position:absolute; inset:0; background:linear-gradient(180deg, rgba(9,23,60,0.66) 0%, rgba(11,30,70,0.45) 40%, rgba(11,30,70,0.15) 100%);\"><\/div>\n<div class=\"kb-cat-textbox\" style=\"position:absolute; inset:auto 5% 7% 5%; color:#fff; text-align:center; display:flex; flex-direction:column; gap:.4rem; align-items:center; justify-content:flex-end;\">\n<div class=\"kb-cat-title\" style=\"font-weight:800; font-size:clamp(20px,3.6vw,34px); line-height:1.2; letter-spacing:.2px; text-shadow:0 1px 2px rgba(0,0,0,.35);\">Common Proxy Issues in Networking and Fixes<\/div>\n<div class=\"kb-cat-meta\" style=\"opacity:1; font-weight:600; font-size:clamp(13px,2.6vw,16px); line-height:1.45; text-shadow:0 1px 2px rgba(0,0,0,.28);\">Quick orientation If a proxy is between your client and the internet, any hiccup can look like a network outage. Below are common proxy issues you&#039;ll see and straightforward ways\u2026<\/div>\n<div class=\"kb-cat-desc\" style=\"opacity:1; font-weight:500; font-size:clamp(12px,2.4vw,15px); line-height:1.5; max-width:900px; text-wrap:balance; text-shadow:0 1px 2px rgba(0,0,0,.25);\">AI<\/div>\n<\/div>\n<\/div>\n<\/figure>\n<p><\/p>\n<ul><\/p>\n<li>Causes: client resolving DNS locally instead of using proxy, browser DNS prefetch, misconfigured proxy DNS settings.<\/li>\n<p><\/p>\n<li>Fixes:\n<ul><\/p>\n<li>Configure the proxy to perform <a href=\"https:\/\/www.hostinger.com\/tutorials\/reduce-dns-lookups\" target=\"_blank\" rel=\"noopener\">dns lookups<\/a> or ensure clients use internal DNS as required.<\/li>\n<p><\/p>\n<li>Disable DNS prefetch in browsers in privacy-sensitive deployments.<\/li>\n<p><\/p>\n<li>Verify resolver settings on the proxy and clients and check \/etc\/resolv.conf, systemd-resolved or equivalent.<\/li>\n<p>\n    <\/ul>\n<p>\n  <\/li>\n<p>\n<\/ul>\n<p><\/p>\n<h3><span class=\"ez-toc-section\" id=\"9_Application-specific_proxy_issues\"><\/span>9) Application-specific proxy issues<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><\/p>\n<p>Symptoms: browsers work but <a href=\"https:\/\/support.hostinger.com\/en\/articles\/1583302-how-to-deploy-a-git-repository\" target=\"_blank\" rel=\"noopener\">git<\/a>, Java, or other command-line tools fail.<\/p>\n<p><\/p>\n<ul><\/p>\n<li>Causes: apps ignore system proxy settings or need explicit configuration.<\/li>\n<p><\/p>\n<li>Fixes:\n<ul><\/p>\n<li>Set environment variables for CLI tools:\n<pre><code>export http_proxy=\"\"<br \/>\nexport https_proxy=\"\"<\/code><\/pre>\n<p>\n      <\/li>\n<p><\/p>\n<li>For Java apps, use JVM flags:\n<pre><code>-Dhttp.proxyHost=proxy.example.com -Dhttp.proxyPort=3128<\/code><\/pre>\n<p>\n      <\/li>\n<p><\/p>\n<li>Check app documentation,some clients require username\/password fields in a separate config or lack NTLM support.<\/li>\n<p>\n    <\/ul>\n<p>\n  <\/li>\n<p>\n<\/ul>\n<p><\/p>\n<h2><span class=\"ez-toc-section\" id=\"Useful_commands_and_checks\"><\/span>Useful <a href=\"https:\/\/www.hostinger.com\/tutorials\/linux-commands\" target=\"_blank\" rel=\"noopener\">commands<\/a> and checks<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><\/p>\n<p>Quick commands by platform to inspect proxy configuration and connectivity.<\/p>\n<p><\/p>\n<h3><span class=\"ez-toc-section\" id=\"Linux_macOS\"><\/span>Linux \/ macOS<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><\/p>\n<pre><code># Check environment variables<br \/>\necho $http_proxy $https_proxy<br># Test connection to proxy port<br \/>\nnc -vz proxy.example.com 3128<br># Test a proxied HTTP request<br \/>\ncurl -v -x  <\/code><\/pre>\n<p><\/p>\n<h3><span class=\"ez-toc-section\" id=\"Windows\"><\/span>Windows<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><\/p>\n<pre><code>REM Show WinHTTP proxy (often used by system services)<br \/>\nnetsh winhttp show proxy<br>REM Check Internet Options (GUI): Internet Options \u2192 Connections \u2192 LAN settings<\/code><\/pre>\n<p><\/p>\n<h3><span class=\"ez-toc-section\" id=\"Proxy_server_checks\"><\/span>Proxy server checks<span class=\"ez-toc-section-end\"><\/span><\/h3>\n<p><\/p>\n<pre><code># On the proxy host (Linux)<br \/>\n<a href=\"https:\/\/www.hostinger.com\/tutorials\/sudo-and-the-sudoers-file\/\" target=\"_blank\" rel=\"noopener\">sudo<\/a> systemctl status squid<br \/>\n<a href=\"https:\/\/www.hostinger.com\/tutorials\/how-to-use-tail-command\/\" target=\"_blank\" rel=\"noopener\">tail<\/a> -n 200 \/var\/log\/squid\/access.log<br \/>\ntail -n 200 \/var\/log\/squid\/cache.log<\/code><\/pre>\n<p><\/p>\n<h2><span class=\"ez-toc-section\" id=\"Logging_and_monitoring\"><\/span>Logging and monitoring<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><\/p>\n<p>Logs are your best friend. Look at access logs for status codes and timestamps, and check error logs for auth and TLS failures.<\/p>\n<p><\/p>\n<ul><\/p>\n<li>Monitor resource use: CPU, memory, network I\/O.<\/li>\n<p><\/p>\n<li>Set up alerting for high error rate, CPU spikes, or low cache hit ratio.<\/li>\n<p>\n<\/ul>\n<p><\/p>\n<h2><span class=\"ez-toc-section\" id=\"Checklist_quick_fixes_to_try_now\"><\/span>Checklist: quick fixes to try now<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><\/p>\n<ul><\/p>\n<li>Confirm proxy hostname and port in client settings.<\/li>\n<p><\/p>\n<li>Try bypassing the proxy to isolate the problem.<\/li>\n<p><\/p>\n<li>Clear browser cache, saved credentials, and PAC file cache.<\/li>\n<p><\/p>\n<li>Verify proxy service is running and reachable from the client.<\/li>\n<p><\/p>\n<li>Install the proxy CA if SSL interception is used.<\/li>\n<p><\/p>\n<li>Check proxy logs for obvious error codes or rejected requests.<\/li>\n<p>\n<\/ul>\n<p><\/p>\n<h2><span class=\"ez-toc-section\" id=\"When_to_escalate\"><\/span>When to escalate<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><\/p>\n<ul><\/p>\n<li>Proxy server is down or repeatedly crashing,engage the server admin.<\/li>\n<p><\/p>\n<li>Authentication failures affecting many users,coordinate with identity team (Kerberos\/AD).<\/li>\n<p><\/p>\n<li>Widespread <a href=\"https:\/\/hostadvice.com\/blog\/domains\/ssl-certificate-errors\/\" target=\"_blank\" rel=\"noopener\">ssl errors<\/a>,security team should confirm certificate and CA trust chains.<\/li>\n<p>\n<\/ul>\n<p><\/p>\n<h2><span class=\"ez-toc-section\" id=\"Summary\"><\/span>Summary<span class=\"ez-toc-section-end\"><\/span><\/h2>\n<p><\/p>\n<p>Proxy issues usually come down to a few categories: connectivity, authentication, TLS, configuration (PAC\/WPAD), caching and application mismatches. Start by confirming addresses and ports, test direct connectivity, and look at the proxy logs. Address authentication and TLS problems by matching client and proxy expectations,install the proxy CA where needed and use the right auth method. For stubborn performance or gateway errors, check upstream health and scale or tune the proxy. If a problem affects many users, capture logs and escalate with precise symptoms and times so the server or identity owners can help.<\/p>\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Quick orientation If a proxy is between your client and the internet, any hiccup can look like a network outage. Below are&hellip;<\/p>\n","protected":false},"author":1,"featured_media":52509,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"content-type":"","_lmt_disableupdate":"","_lmt_disable":"","footnotes":""},"categories":[4594,9405,86,4593,9,1,3,5,10,4,11,88,8,2],"tags":[13340,13339,10799,12831,10794,13217,11419,1781,13345,13342,13344,13215,13343,13341,13218,13346],"class_list":["post-52508","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-networking","category-ai","category-computer-security","category-databases","category-domains","category-general","category-php-scripts","category-seo","category-servers","category-ssl-certificates","category-support","category-web-hosting","category-website-security","category-wordpress","tag-common-proxy-issues","tag-common-proxy-issues-in-networking-and-fixes","tag-connectivity-issues","tag-dns-issues","tag-firewall-issues","tag-http-proxy","tag-network-troubleshooting","tag-networking","tag-proxy-authentication","tag-proxy-configuration","tag-proxy-fixes","tag-proxy-server","tag-proxy-settings","tag-proxy-troubleshooting","tag-socks-proxy","tag-ssl-tls-problems"],"_links":{"self":[{"href":"https:\/\/infinitydomainhosting.com\/kb\/wp-json\/wp\/v2\/posts\/52508","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/infinitydomainhosting.com\/kb\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/infinitydomainhosting.com\/kb\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/infinitydomainhosting.com\/kb\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/infinitydomainhosting.com\/kb\/wp-json\/wp\/v2\/comments?post=52508"}],"version-history":[{"count":1,"href":"https:\/\/infinitydomainhosting.com\/kb\/wp-json\/wp\/v2\/posts\/52508\/revisions"}],"predecessor-version":[{"id":52510,"href":"https:\/\/infinitydomainhosting.com\/kb\/wp-json\/wp\/v2\/posts\/52508\/revisions\/52510"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/infinitydomainhosting.com\/kb\/wp-json\/wp\/v2\/media\/52509"}],"wp:attachment":[{"href":"https:\/\/infinitydomainhosting.com\/kb\/wp-json\/wp\/v2\/media?parent=52508"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/infinitydomainhosting.com\/kb\/wp-json\/wp\/v2\/categories?post=52508"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/infinitydomainhosting.com\/kb\/wp-json\/wp\/v2\/tags?post=52508"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}