[FS#253] Multicast over wireless ceases to work properly after a while on ath9k with many clients connected

[LEDE Bugs]

The following task has a new comment added:

FS#253 - Multicast over wireless ceases to work properly after a while on ath9k with many clients connected
User who did this - Neil Crawforth (neil)

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I just passed 100 hours uptime with 16 wifi clients (I had 13 when I last saw multicast stop working).
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More information can be found at the following URL:
https://bugs.lede-project.org/index.php?do=details&task_id=253#comment1472