Customer observed there were some issues with multicast traffic.

Multicast channels were being affected.

When we verified the pfe routes, we see exhaustion of MCAST/HOST tables.

This is root cause of the issue observed.

{master:0}
root@QFX5K> show pfe route summary hw 
Oct 23 00:17:43

Slot 0

Unit: 0
Profile active: lpm-profile
Type            Max       Used      Free      % free
----------------------------------------------------
IPv4 Host       16384     8792      120       0.73
IPv4 LPM        131072    24815     106257    81.07
IPv4 Mcast      8192      1943      60        0.73

IPv6 Host       8192      1793      60        0.73
IPv6 LPM(< 64)  16385     6927      9458      57.72
IPv6 LPM(> 64)  16385     2721      13664     83.39
IPv6 Mcast      4096      0         31        0.76

{master:0}

From logs we observe below errors; Indicating table full

Oct 23 00:41:36 2025  QFX5K fpc0 brcm_rt_ip_entry_install:852Failed to h/w update ip mc route entry (status:-6 action:0)
Oct 23 00:41:36 2025  QFX5K fpc0 brcm_rt_ip_mc_entry_install:3471In function call, Err: ipmc install failed
Oct 23 00:41:36 2025  QFX5K fpc0 brcm_rt_ip_entry_install:852Failed to h/w update ip mc route entry (status:-6 action:0)
Oct 23 00:42:12 2025  QFX5K fpc0 brcm_rt_ip_mc_entry_install:3471In function call, Err: ipmc install failed
Oct 23 00:42:12 2025  QFX5K fpc0 brcm_rt_ip_entry_install:852Failed to h/w update ip mc route entry (status:-6 action:0)
Oct 23 00:43:28 2025  QFX5K fpc0 brcm_rt_ip_mc_entry_install:3471In function call, Err: ipmc install failed
Oct 23 00:43:28 2025  QFX5K fpc0 brcm_rt_ip_entry_install:852Failed to h/w update ip mc route entry (status:-6 action:0)
Oct 23 00:43:50 2025  QFX5K fpc0 brcm_rt_ip_mc_entry_install:3471In function call, Err: ipmc install failed
Oct 23 00:43:50 2025  QFX5K fpc0 brcm_rt_ip_entry_install:852Failed to h/w update ip mc route entry (status:-6 action:0)
Oct 23 00:44:17 2025  QFX5K fpc0 brcm_rt_ip_mc_entry_install:3471In function call, Err: ipmc install failed
Oct 23 00:44:17 2025  QFX5K fpc0 brcm_rt_ip_entry_install:852Failed to h/w update ip mc route entry (status:-6 action:0)
Oct 23 00:44:20 2025  QFX5K fpc0 brcm_rt_ip_mc_entry_install:3471In function call, Err: ipmc install failed
Oct 23 00:44:20 2025  QFX5K fpc0 brcm_rt_ip_entry_install:852Failed to h/w update ip mc route entry (status:-6 action:0)

Need to reduce the scaling of MCAST/HOST for V4 /V6.