Levandor

Runbook: AirPlay to the TV (telep-tv) isn't working

4 min read

Mid-incident? Try this first

On the mainframe, re-publish mDNS + restart the receiver:

ssh levander@100.115.209.87        # mainframe, when LAN DNS is down
sudo systemctl restart avahi-daemon uxplay

Then re-open the AirPlay picker on the phone/Mac. The cast target is telep-tv — it is the mainframe (telep-mainframe), served by uxplay.service on DISPLAY=:0, which needs camwall-x.service (the persistent Xorg :0) up.

Symptoms — pick the one that matches

  • (a) telep-tv doesn’t appear on the client at all.
  • (b) Appears, but tapping it does nothing / spins.
  • (c) Connects, but the TV keeps showing the camera wall — no mirrored video.
  • (d) Video works but there’s no audio.

Diagnose → Fix by symptom

(a) Not appearing

  1. Is it advertising at all? On the mainframe: 
    avahi-browse -atp | grep telep-tv
avahi-browse -rtp _airplay._tcp     # should show ONLY the enp5s0 / 192.168.1.123 record
  2. Advertising, but only a WiFi client can’t see it → router AP-isolation mDNS bug on telep-router. netifd re-injects ap_isolate=1 into the running hostapd conf. uci isolate=0 does NOT fix it — patch the netifd file: 
    ssh root@100.69.112.32
grep -n 'json_add_boolean isolate 1' /lib/netifd/netifd-wireless.sh
sed -i '309s/^/#DISABLED-airplay-fix#/' /lib/netifd/netifd-wireless.sh
wifi down; wifi up

    REAPPLY after any OpenWrt sysupgrade — a firmware upgrade reverts /lib/netifd/ and re-isolates telep1. Re-grep the line (numbers shift) and re-sed. 2b. dns-sd -L resolves from the Mac but dns-sd -B (browse) never shows telep-tv, and it fails on BOTH bands → the 10G-port multicast bug, NOT 5 GHz. The box's mDNS multicast (verified on the wire via tcpdump on enp5s0 → 224.0.0.251) never gets flooded from its br-lan port 2 = 10G link out to Wi-Fi, while 1G-port devices (the HP printer) do reach Wi-Fi. Unicast is fine (ping/ssh/resolve/AirPlay-connect all work) — only multicast discovery fails. Ruled out: multicast_to_unicast (tried=no change), Mac mDNS cache flush, and band (fails on 2.4 and 5 GHz). Quick fix: move the box cable to a 1G LAN port; keep-10G fix: run an mDNS reflector re-advertising telep-tv at the box IP:port. Full diagnosis: 2026-08-30-telep-tv-airplay-10g-port-multicast-not-flooded. [!warning] Old "5 GHz cross-band client isolation" blame is WRONG for AirPlay discovery For months this symptom was pinned on the router's 5 GHz cross-band isolation (Problem 3 — Wi-Fi cross-band client isolation (driver-level)). That's a separate wifi↔wifi unicast issue (Bambu printer). telep-tv discovery is a wired-10G-port→Wi-Fi multicast issue and is band-independent.

  3. Advertising on junk interfaces (docker/veth/loopback) → avahi multi-iface bug. Confirm /etc/avahi/avahi-daemon.conf has: 
    [server]
allow-interfaces=enp5s0
    Then sudo systemctl restart avahi-daemon uxplay.
  4. _airplay._tcp/_raop._tcp return NOTHING but avahi still advertises other services (_nut._tcp, the HP printer) → uxplay’s avahi-compat layer didn’t re-register after a restart/D-Bus hiccup. Restart avahi FIRST, then uxplay (order matters — bouncing uxplay alone hits the same race): 
    sudo systemctl restart avahi-daemon
sleep 2
sudo systemctl restart uxplay
    Detail: 2026-08-30-telep-tv-mdns-vanishes-after-uxplay-restart.

(b) Appears but casting does nothing

  • Usually the same two causes as (a) — the client latched onto an unreachable docker/loopback record, or a boot-time DHCP flap dropped the mDNS group. Enforce allow-interfaces=enp5s0 (above) and sudo systemctl restart avahi-daemon uxplay.
  • Sanity: systemctl is-active uxplay camwall-x — both must be active.

(c) Connects but the camera wall stays up (no video)

  • The handoff wrapper /usr/local/bin/uxplay-cast.sh matches uxplay stdout strings to stop/restart the camwall. iPhone log strings can differ from the verified macOS ones → the grid never yields. 
    cat /run/uxplay/casting          # 1 = mid-cast (grid should be stopped)
sudo systemctl restart uxplay camwall
  • If it recurs only from iOS, the disconnect trigger strings need an iPhone-specific re-check (verified markers so far are macOS-only). See Real uxplay 1.71 log markers (verified from a live macOS mirror).

(d) No audio

  • The sink is alsasink device=plughw:1,3 = ALSA card 1 device 3 = “LG TV SSCR2” (NVIDIA HDMI). Confirm the card is present: 
    aplay -l | grep -i 'card 1'
  • If the card is missing, the HDMI/TV link renegotiated — reconnect HDMI, then sudo systemctl restart uxplay.

Deeper causes / links

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