Proxies: setup, and when one fails

Proxy types

SOCKS5 and HTTP, with or without a login. HTTPS is an HTTP proxy reached over TLS.

Setting a proxy

In the profile editor (⋯ → Edit…), Connection offers No Proxy, From the List and New. Under New, paste the proxy as the provider gave it: host:port:user:pass, user:pass@host:port, socks5://user:pass@host:port or host:port. The scheme sets the type: socks5:// (or socks5h://, socks://), http://, https://.

Without a scheme, Check or Save finds the type; with none found, nothing is saved.

Bypass domains (comma-separated) takes domains out of the proxy. Changes apply at the next launch. More: creating a profile.

List and checks

The list is under Proxies in the Profiles window's sidebar, encrypted, on this Mac only; each profile keeps its own copy.

• Add takes one proxy in the same field; Import… takes a list, pasted or From File…, one per line, with text after # as its name. Unreadable lines are listed with the reason; repeats (same host, port and user name) are skipped. By default, lines without a scheme get their type at the first check; no profile gets them before.
• Assign to Profiles… - one proxy for all ticked profiles, or several in turn, round-robin. A running profile keeps its proxy until it stops.
• ⋯ → Edit… reaches the profiles using the proxy; ⋯ → Export… writes user names and passwords in plaintext.

Check All and Check Selected test each proxy through itself: Address, Connection, Handshake as SOCKS5 and HTTP, Login, Tunnel, Through the proxy (a geolocation request). Never directly. A working proxy shows its country, city, exit IP, network and latency (median of three tunnels); the selected one, a report with What to do. Checks run only on request.

Time zone and language

At launch the profile asks a geolocation service through the proxy (ipinfo.io, then geojs.io, ipwho.is and ipapi.co), which sees the proxy's address, not this Mac's. The profile takes the exit's time zone and its country's language, such as de-DE for Germany: Time zone and language → From the connection in Location and Language, the default.

The answer is awaited up to three seconds, or a second if the exit is known. If no service answers, the profile keeps its last launch's time zone and language, or this Mac's, and Lumen says so. With Each profile its own app in the Dock off, the first profile launched sets the language for the run. Rotating proxies: Warn when the proxy's IP changes.

DNS, WebRTC, UDP

• DNS. The proxy, SOCKS5 or HTTP, resolves site names itself. This Mac looks up only the proxy's address; DNS prefetching is blocked.
• WebRTC is off with a proxy, whatever the setting: its UDP would go around it.
• QUIC (HTTP/3) is not used: pages go through the proxy over HTTP/2, and a profile in its own process may send no UDP.
• This Mac's addresses (127.0.0.1, localhost) are closed to pages; local-network ones go through the proxy.

Only two settings lead around the proxy: Bypass domains (comma-separated) and Safe Browsing (lookups bypass the proxy), both inactive by default. The app's own sync and update check go out directly.

In the latest registered CI run, none of the 2,410 packets captured during the self-test went around the proxy.

When the proxy fails

While the proxy is down, pages do not load: Lumen never falls back to a direct connection. The CI self-test checks this with unreachable and unresolvable proxies.

Not started. An unusable proxy address, or an HTTP proxy wanting a login the profile lacks (seen when the launch looks up the exit), stops the launch. If found later, the profile is stopped.

Started, proxy not working. At launch Lumen asks the proxy itself once; if it fails, the Profiles window shows “…” loads no pages, the report, Check Proxy and Show in Proxies. In Settings → Proxies → A proxy that does not work, Do not start the profile keeps such a profile stopped; the default is Start the profile, say why.

Fails mid-session. Pages stop loading; the app's window shows Page could not be loaded and the reason. The Profiles window says nothing: the proxy is asked only at launch.

To recover, click Check Proxy: if it works, reload the page, or reopen the profile if the type was corrected; if not, fix the proxy (⋯ → Edit…) or assign another and relaunch. More: what to do when something fails.