What causes "network %s fail" in XX-net/XX-Net?

Verify physical connectivity and DNS resolution

network %s fail

Error message

network %s fail

What it means

After trying all configured test URLs, none succeeded, so the network type is declared down: network_stat set to 'Fail' and last_check_time recorded. The checker will re-check later based on this state.

Source

Thrown at code/default/gae_proxy/local/check_local_network.py:144

        self._checking_num += 1
        self._checking_lock.release()

        network_ok = False
        for url in self.urls:
            if self._test_host(url):
                network_ok = True
                break
            else:
                if __name__ == "__main__":
                    xlog.warn("test %s fail", url)
                time.sleep(1)

        if network_ok:
            self.last_check_time = time.time()
            self.report_ok()
            xlog.debug("network %s is ok, cost:%d ms", self.type, 1000 * (time.time() - time_now))
        else:
            xlog.warn("network %s fail", self.type)
            self.network_stat = "Fail"
            self.last_check_time = time.time()

        self._checking_lock.acquire()
        self._checking_num -= 1
        self._checking_lock.release()

    def triger_check_network(self, fail=False, force=False):
        time_now = time.time()
        if not force:
            if self._checking_num > 0:
                return

            if fail or self.network_stat != "OK":
                # Fail or unknown
                if time_now - self.last_check_time < 3:
                    return
            else:

View on GitHub (pinned to cfa5bc17b6)

Solutions

Verify physical connectivity and DNS resolution
If direct network is blocked but proxy works, rely on the proxy path and let XX-Net recheck automatically
Adjust the test URL list to include reachable hosts
Check system firewall/antivirus blocking the process

Defensive patterns

Strategy: fallback

Prevention

Rely on proxy paths when the direct path reports Fail
Keep at least one guaranteed-reachable test URL
Re-check automatically on interval instead of caching failure

When it happens

Trigger: _simple_check_worker exhausting self.urls with every _test_host failing — total outage or full blocking of that network path (e.g. direct connection completely blocked).

Common situations: No internet, DNS totally broken, all test domains blocked/firewalled, or system proxy misrouting all traffic.

Related errors

AI-assisted analysis of XX-net/XX-Net@cfa5bc17b6 (2026-08-27). Data as JSON: /api/errors/f31b7baa1af0c079. Report an issue: GitHub.