fix: idn ping errors

server/util-server.js

@@ -157,6 +157,16 @@ exports.pingAsync = function (
     deadline = PING_GLOBAL_TIMEOUT_DEFAULT,
     timeout = PING_PER_REQUEST_TIMEOUT_DEFAULT
 ) {
+    try {
+        const url = new URL(`http://${destAddr}`);
+        destAddr = url.hostname;
+        if (destAddr.startsWith("[") && destAddr.endsWith("]")) {
+            destAddr = destAddr.slice(1, -1);
+        }
+    } catch (e) {
+        // ignore
+    }
+
     return new Promise((resolve, reject) => {
         ping.promise
             .probe(destAddr, {

test/backend-test/test-util-server.js

@@ -0,0 +1,57 @@
+const { describe, test } = require("node:test");
+const assert = require("node:assert");
+const { pingAsync } = require("../../server/util-server");
+
+describe("Server Utilities: pingAsync", () => {
+    test("should convert IDN domains to Punycode before pinging", async () => {
+        const idnDomain = "münchen.de";
+        const punycodeDomain = "xn--mnchen-3ya.de";
+
+        await assert.rejects(pingAsync(idnDomain, false, 1, "", true, 56, 1, 1), (err) => {
+            if (err.message.includes("Parameter string not correctly encoded")) {
+                assert.fail("Ping failed with encoding error: IDN was not converted");
+            }
+            assert.ok(
+                err.message.includes(punycodeDomain),
+                `Error message should contain the Punycode domain "${punycodeDomain}". Got: ${err.message}`
+            );
+            return true;
+        });
+    });
+
+    test("should strip brackets from IPv6 addresses before pinging", async () => {
+        const ipv6WithBrackets = "[2606:4700:4700::1111]";
+        const ipv6Raw = "2606:4700:4700::1111";
+
+        await assert.rejects(pingAsync(ipv6WithBrackets, true, 1, "", true, 56, 1, 1), (err) => {
+            assert.strictEqual(
+                err.message.includes(ipv6WithBrackets),
+                false,
+                "Error message should not contain brackets"
+            );
+            // Allow either the IP in the message (local) OR "Network is unreachable"
+            const containsIP = err.message.includes(ipv6Raw);
+            const isUnreachable =
+                err.message.includes("Network is unreachable") || err.message.includes("Network unreachable");
+            // macOS error when IPv6 stack is missing
+            const isMacOSError = err.message.includes("nodename nor servname provided");
+            assert.ok(
+                containsIP || isUnreachable || isMacOSError,
+                `Ping failed correctly, but error message format was unexpected.\nGot: "${err.message}"\nExpected to contain IP "${ipv6Raw}" OR be a standard network error.`
+            );
+            return true;
+        });
+    });
+
+    test("should handle standard ASCII domains correctly", async () => {
+        const domain = "invalid-domain.test";
+        await assert.rejects(pingAsync(domain, false, 1, "", true, 56, 1, 1), (err) => {
+            assert.strictEqual(err.message.includes("Parameter string not correctly encoded"), false);
+            assert.ok(
+                err.message.includes(domain),
+                `Error message should contain the domain "${domain}". Got: ${err.message}`
+            );
+            return true;
+        });
+    });
+});