How IPTV reaches the TV
The ISP sends channels as multicast: one stream for everyone, and the TV "subscribes" to a channel with IGMP. A home router drops those subscriptions by default, so channels do not open. An IGMP proxy forwards subscriptions to the ISP and delivers multicast into the home network. IGMP snooping on the bridge keeps each stream on the ports where it is watched instead of flooding the whole network.
VLANs and set-top boxes
ISPs often deliver IPTV in a separate VLAN; the number is in the contract or with support. With an ISP set-top box, the simplest option is a dedicated port bridged to that VLAN, so the box works as if there were no router.
Troubleshooting
- Channels play for 5–10 seconds and freeze: repeated IGMP queries are blocked. Check the IGMP firewall rule and alternative-subnets / altnet 0.0.0.0/0.
- Works on a cable, breaks on Wi-Fi: use udpxy.
- The whole network slows down while TV is on: IGMP snooping is off.
Related: playlist checker, IPTV players, MikroTik generator.