Routing on Margrop Blog https://blog.margrop.net/en/tag/routing/ Recent content in Routing on Margrop Blog Hugo en-US Mon, 01 Jun 2026 18:00:00 +0800 VPN Connected, But Internal Hostnames Won't Resolve? A Complete macOS Routing Table Walkthrough https://blog.margrop.net/en/post/macos-routing-table-vpn-troubleshooting/ Mon, 01 Jun 2026 18:00:00 +0800 https://blog.margrop.net/en/post/macos-routing-table-vpn-troubleshooting/ <blockquote> <p><strong>TL;DR:</strong></p> <p>When two VPNs run side-by-side on macOS (e.g. <code>utun0</code> and <code>utun15</code>), an aggregate <code>10.0.0.0/8</code> route pushed by one of them can silently &ldquo;swallow&rdquo; every address in the 10.x.x.x range — including the one you actually wanted to reach on the other VPN. DNS resolves fine; TCP/ICMP just hangs. <strong><code>route -n get</code> is the first knife you should reach for.</strong></p> </blockquote>