【Typical Case】How to Troubleshoot Wireless IPTV Freezing and Wireless Client Connection Failures on RAP1200P?

Keywords

RAP, wireless IPTV freezing, wireless clients failed to obtain IP addresses, wireless client disconnection
Fault Description

(1) IPTV keeps freezing or failing when an IPTV box is connected wirelessly to the RAP.
(2) Wireless clients connected to the RAP failed to obtain IP addresses or access the Internet after obtaining IP addresses.
Device Model and Firmware

Device Type	Device Model	Firmware Version
Core  switch	S5300-24GT4XS-E
Access  switch	S2915-24GT4MS-P-L
Access  point	RAP1200(P)	ReyeeOS  2.280.0.1713

Cause Analysis

1. Check the multicast configuration and multicast traffic of the switch at uplink ofthe RAP. It is found that multicast is not configured on the switch, resulting in multicast packets being broadcast to the RAP. The multicast traffic, however, is not heavy.

2. Check air interface resources of the RAP. It is found that nearly all air interfacere sources are occupied by unknown multicast packets forwarded by the switch.

3. Check the customer's multicast topology (Layer 2 multicast, with the IPTV server connected to port 15 of the core switch). Next, configure multicast settings on the core switch and the access switch to prevent the access switch from forwarding unknown multicast packets to the RAP1200P. The configuration is as follows:
On the core switch, run the following commands:
ip igmp snooping ivgl
ip igmp snooping querier
ip igmp snooping querier address 1.1.1.1
ip igmp snooping vlan 60 querier
ip igmp snooping vlan 60 mrouter interface GigabitEthernet 0/15
4. After the configuration, the customer confirms that the issue with IPTV freezing and client connection is resolved.
Root Cause

Restrictions on the multicast function of the RAP1200P:
Unknown multicast packets are forwarded from Layer 2 switches to the APs. Wi-Fi 5 APs directly forward multicast packets to the air interface, causing an extremely high utilization of air interface resources.
At the customer site, since the Wi-Fi 5 AP is not configured to discard unknown multicast packets, it is necessary to configure the switch at uplink to discard unknown multicast packets to prevent it from being forwarded to APs at downlink.
Solution

1. Configure IGMP on the switch at uplink to filter out unknown multicast packets and to forward only the multicast packets intended for RAP1200P based on the table entries.
2. Wi-Fi 6 and Wi-Fi 7 access points can be configured to discard unknown multicast packets. With this configuration, if the switch forwards unknown multicast packets to the APs, the APs will not transmit these packets over the air, helping to prevent IPTV freezing and wireless client connection issues.