4220 stacking stability

Brent_Addis — Mon, 23 Feb 2026 19:29:58 GMT

Has anybody had any issues with stackiing stability?

We have a campus environment, which is predominantly fabric connect, with 3-4 2 and 4 stack 4220's running XOS.

Things were stable mostly last year, but since the students have been back this year, we are having crashes/reboots on fibre facing switches while the rest of the stack stays up.

At first we thought it was MDNS, so we have acl's dropping destination 224.0.0.248/29 at the port level however it doesn't seem to have helped, with switches crashing overnight when no students are onsite.

It's logged with TAC but I suspect they'll point at MDNS again.

We've upgraded firmware to latest 33.5 and hasn't helped.

02/24/2026 01:20:58.74 <Warn:DM.Warning> Slot-2: PRIMARY NODE (Slot-1) DOWN
02/24/2026 01:20:58.74 <Warn:DM.Warning> Slot-2: NM: Old Primary's state is UNKNOWN
02/24/2026 01:20:59.12 <Erro:HAL.IPv4ACL.Error> Slot-1: Counter flush failed unit 17
02/24/2026 01:20:59.24 <Warn:DM.Warning> Slot-1: BACKUP is NOT in SYNC
02/24/2026 01:20:59.27 <Warn:DM.Warning> Slot-1: BACKUP NODE (Slot-2) DOWN
02/24/2026 01:20:59.94 <Erro:HAL.IPv4ACL.Error> Slot-2: Counter flush failed unit 1
02/24/2026 01:20:59.94 <Erro:HAL.IPv4ACL.Error> Slot-2: Previous message repeated 2 additional times in the last 1 second(s)
02/24/2026 01:20:59.94 <Erro:HAL.IPv4ACL.Error> Slot-2: Counter flush failed unit 1
02/24/2026 01:20:59.94 <Erro:HAL.IPv4ACL.Error> Slot-2: Counter flush failed unit 1
02/24/2026 01:20:59.94 <Erro:HAL.IPv4ACL.Error> Slot-2: Counter flush failed unit 1
02/24/2026 01:20:59.94 <Erro:HAL.IPv4ACL.Error> Slot-2: Previous message repeated 8 additional times in the last 1 second(s)
02/24/2026 01:20:59.94 <Erro:HAL.IPv4ACL.Error> Slot-2: Counter flush failed unit 1
02/24/2026 01:20:59.94 <Erro:HAL.IPv4ACL.Error> Slot-2: Counter flush failed unit 1
02/24/2026 01:20:59.94 <Erro:HAL.IPv4ACL.Error> Slot-2: Counter flush failed unit 1
02/24/2026 01:20:59.94 <Erro:HAL.IPv4ACL.Error> Slot-2: Counter flush failed unit 1
02/24/2026 01:20:59.94 <Erro:HAL.IPv4ACL.Error> Slot-2: Counter flush failed unit 1
02/24/2026 01:20:59.94 <Erro:HAL.IPv4ACL.Error> Slot-2: Counter flush failed unit 1
02/24/2026 01:20:59.94 <Erro:HAL.IPv4ACL.Error> Slot-2: Counter flush failed unit 1
02/24/2026 01:20:59.94 <Erro:HAL.IPv4ACL.Error> Slot-2: Counter flush failed unit 1
02/24/2026 01:20:59.94 <Erro:HAL.IPv4ACL.Error> Slot-2: Counter flush failed unit 1
02/24/2026 01:20:59.94 <Erro:HAL.IPv4ACL.Error> Slot-2: Counter flush failed unit 1
02/24/2026 01:20:59.94 <Erro:HAL.IPv4ACL.Error> Slot-2: Counter flush failed unit 1
02/24/2026 01:20:59.94 <Erro:HAL.IPv4ACL.Error> Slot-2: Counter flush failed unit 1
02/24/2026 01:20:59.94 <Erro:HAL.IPv4ACL.Error> Slot-2: Counter flush failed unit 1
02/24/2026 01:20:59.94 <Erro:HAL.IPv4ACL.Error> Slot-2: Counter flush failed unit 1
02/24/2026 01:20:59.94 <Erro:HAL.IPv4ACL.Error> Slot-2: Counter flush failed unit 1
02/24/2026 01:20:59.94 <Erro:HAL.IPv4ACL.Error> Slot-2: Counter flush failed unit 1
02/24/2026 01:20:59.94 <Erro:HAL.IPv4ACL.Error> Slot-2: Counter flush failed unit 1
02/24/2026 01:20:59.94 <Erro:HAL.IPv4ACL.Error> Slot-2: Counter flush failed unit 1
02/24/2026 01:20:59.94 <Erro:HAL.IPv4ACL.Error> Slot-2: Previous message repeated 2 additional times in the last 1 second(s)
02/24/2026 01:20:59.94 <Erro:HAL.IPv4ACL.Error> Slot-2: Counter flush failed unit 1
02/24/2026 01:20:59.94 <Erro:HAL.IPv4ACL.Error> Slot-2: Counter flush failed unit 1
02/24/2026 01:20:59.94 <Erro:HAL.IPv4ACL.Error> Slot-2: Counter flush failed unit 1
02/24/2026 01:20:59.94 <Erro:HAL.IPv4ACL.Error> Slot-2: Counter flush failed unit 1
02/24/2026 01:20:59.94 <Erro:HAL.IPv4ACL.Error> Slot-2: Counter flush failed unit 1
02/24/2026 01:20:59.94 <Erro:HAL.IPv4ACL.Error> Slot-2: Counter flush failed unit 1
02/24/2026 01:20:59.94 <Erro:HAL.IPv4ACL.Error> Slot-2: Previous message repeated 5 additional times in the last 1 second(s)
02/24/2026 01:20:59.94 <Erro:HAL.IPv4ACL.Error> Slot-2: Counter flush failed unit 1
02/24/2026 01:20:59.94 <Erro:HAL.IPv4ACL.Error> Slot-2: Counter flush failed unit 1
02/24/2026 01:20:59.94 <Erro:HAL.IPv4ACL.Error> Slot-2: Previous message repeated 12 additional times in the last 1 second(s)
02/24/2026 01:20:59.94 <Erro:HAL.IPv4ACL.Error> Slot-2: Counter flush failed unit 1
02/24/2026 01:20:59.94 <Erro:HAL.IPv4ACL.Error> Slot-2: Counter flush failed unit 1
02/24/2026 01:20:59.95 <Erro:HAL.IPv4ACL.Error> Slot-2: Previous message repeated 17 additional times in the last 1 second(s)
02/24/2026 01:21:05.13 <Erro:DM.Error> Slot-2: Node State[5] = FAIL (Dual Master)
02/24/2026 01:21:05.61 <Warn:DM.Warning> Slot-2: Slot-2 FAILED (1) Dual Master
02/24/2026 01:21:07.62 <Warn:EPM.all_shutdown> Slot-2: Shutting down all processes
02/24/2026 01:22:17.09 <Noti:EPM.wd_warm_reset> Slot-2: Changing to watchdog warm reset mode
02/24/2026 01:22:17.22 <Noti:EPM.start> Slot-2: EPM Started
02/24/2026 01:22:17.57 <Noti:NM.StrtProc> Slot-2: The Node Manager (NM) has started processing.
02/24/2026 01:22:21.04 <Noti:log.serverStarted> Slot-2: The Event Management System logging server has started.
02/24/2026 01:22:21.39 <Noti:DM.Notice> Slot-2: DM started

02/24/2026 01:22:21.78 <Info:EAPS.DmnInfo> Slot-2: EAPSD - License string updated: basic,master,fast,moredomains,multi,shared
02/24/2026 01:22:30.17 <Info:EAPS.DmnInfo> Slot-2: EAPSD - License string updated: basic,master,fast,moredomains,multi,shared
02/24/2026 01:22:36.79 <Info:HAL.Sys.Info> Slot-2: Starting hal initialization ....
02/24/2026 01:22:58.07 <Info:HAL.Sys.Info> Slot-2: BOOTROM 02/23/2026 12:21:39.00 U-Boot 3.5.0.11
02/24/2026 01:22:58.08 <Info:HAL.Sys.Info> Slot-2: Daily Flash Information: EC:214(0) BB:4(0)
02/24/2026 01:22:58.19 <Info:HAL.Card.Info> Slot-2: Bluetooth capability is supported
02/24/2026 01:22:58.22 <Info:HAL.Sys.Info> Slot-2: Internal PSU-1 in slot 2 is present.
02/24/2026 01:22:58.22 <Info:HAL.Sys.Info> Slot-2: Internal PSU-1 in slot 2 is powered off.
02/24/2026 01:22:58.22 <Info:HAL.Sys.Info> Slot-2: Internal PSU-2 in slot 2 is present.
02/24/2026 01:22:58.22 <Info:HAL.Sys.Info> Slot-2: Internal PSU-2 in slot 2 is powered off.
02/24/2026 01:22:58.23 <Info:HAL.Card.Info> Slot-2: Module in Slot-2 is inserted
02/24/2026 01:22:58.27 <Info:HAL.Sys.Info> Slot-2: Hal initialization done.
02/24/2026 01:22:58.69 <Info:nl.init> Slot-2: Network Login framework has been initialized
02/24/2026 01:22:58.83 <Noti:DM.Notice> Slot-2: Node State[1] = INIT
02/24/2026 01:22:59.06 <Noti:DM.Notice> Slot-2: Slot-2 being Powered ON
02/24/2026 01:23:00.73 <Info:DOSProt.Init> Slot-2: DOS protect application started successfully
02/24/2026 01:23:01.28 <Info:HAL.Sys.Info> Slot-2: PSU 54V DC output changed.
02/24/2026 01:23:02.65 <Info:telnetd.info> Slot-2: **** telnetd started *****
02/24/2026 01:23:06.83 <Info:tftpd.info> Slot-2: **** tftpd started *****
02/24/2026 01:23:09.26 <Info:HAL.Port.Info> Slot-2: Stacking port 1:1 link up at 10Gbps.
02/24/2026 01:23:09.26 <Info:HAL.Port.Info> Slot-2: Stacking port 1:2 link up at 10Gbps.
02/24/2026 01:23:09.26 <Info:HAL.Port.Info> Slot-2: Stacking port 2:1 link up at 10Gbps.
02/24/2026 01:23:09.26 <Info:HAL.Port.Info> Slot-2: Stacking port 2:2 link up at 10Gbps.
02/24/2026 01:23:09.85 <Noti:DM.Notice> Slot-2: Transitioning slot 1 to UNKNOWN rather than MASTER
02/24/2026 01:23:10.27 <Noti:DM.Notice> Slot-2: Previous message repeated 6 additional times in the last 1 second(s)
02/24/2026 01:23:10.30 <Info:HAL.Card.Info> Slot-2: Module in Slot-1 is inserted
02/24/2026 01:23:13.13 <Noti:HAL.Sys.Notice> Slot-2: Boot-time diagnostics completed successfully.
02/24/2026 01:23:28.83 <Info:DM.Info> Slot-2: Node INIT DONE ....
02/24/2026 01:23:28.83 <Noti:DM.Notice> Slot-2: Node State[2] = STANDBY
02/24/2026 01:23:33.83 <Noti:DM.Notice> Slot-2: Setting time from Mon Feb 23 12:23:33 2026 to Mon Feb 23 12:23:33 2026
02/24/2026 01:23:40.28 <Noti:DM.Notice> Slot-2: Node State[3] = BACKUP
02/24/2026 01:23:40.29 <Noti:DM.Notice> Slot-2: Setting time from Tue Feb 24 01:23:40 2026 to Tue Feb 24 01:23:40 2026
02/24/2026 01:23:42.45 <Warn:cm.configNotInSync> Slot-1: Backup node has different configuration files than primary node. Auto configuration file synchronization will be performed.
02/24/2026 01:23:52.31 <Info:HAL.Sys.Info> Slot-2: Internal PSU-1 in slot 2 is disconnected.
02/24/2026 01:23:52.31 <Info:HAL.Sys.Info> Slot-2: Internal PSU-2 in slot 2 is disconnected.
02/24/2026 01:23:56.03 <Info:EPM.wdg_enable> Slot-2: Watchdog enabled
02/24/2026 01:24:12.44 <Noti:EPM.system_stable> Slot-2: System is stable. Change to warm reset mode
02/24/2026 01:24:12.54 <Erro:cm.sys.LoadApplCfgObjFail> Slot-2: "ospf" application failed to load "ospfInterface" configuration object: Error: No OSPF interface SYS_VLAN_4048

02/24/2026 01:24:12.54 <Warn:log.NVRAMFull> Slot-2: NVRAM is full, old messages are overwritten.
02/24/2026 01:24:15.76 <Noti:thttpd.CrtfctVld> Slot-2: The provided SSL certificate (CN:*.extremenetworks.com) is valid.
02/24/2026 01:24:17.37 <Info:SNMP.Master.InitDone> Slot-2: snmpMaster initialization complete
02/24/2026 01:24:23.99 <Noti:exsshd.CfgHostKeyAlgWeak> Slot-2: The configured host key algorithm(s), ssh-rsa, is/are weaker than what is recommended.
02/24/2026 01:24:24.43 <Info:HAL.Card.Info> Slot-2: Module in Slot-2 is operational
02/24/2026 01:24:27.05 <Noti:DM.Notice> Slot-2: Slot-1 being Powered ON
02/24/2026 01:24:27.89 <Info:HAL.IPv4ACL.Info> Slot-2: Synching ACLs to Slot-1
02/24/2026 01:24:27.90 <Info:HAL.IPv4ACL.Info> Slot-2: Done synching ACLs to Slot-1
02/24/2026 01:24:32.04 <Info:vlan.msgs.portLinkStateUp> Slot-2: Port 1:3 link UP at speed 1 Gbps and full-duplex
02/24/2026 01:24:32.20 <Info:vlan.msgs.portLinkStateUp> Slot-2: Port 1:4 link UP at speed 100 Mbps and full-duplex
02/24/2026 01:24:32.23 <Info:vlan.msgs.portLinkStateUp> Slot-2: Port 1:7 link UP at speed 1 Gbps and full-duplex
02/24/2026 01:24:32.26 <Info:vlan.msgs.portLinkStateUp> Slot-2: Port 1:9 link UP at speed 1 Gbps and full-duplex
02/24/2026 01:24:32.27 <Info:vlan.msgs.portLinkStateUp> Slot-2: Port 1:10 link UP at speed 1 Gbps and full-duplex
02/24/2026 01:24:32.30 <Info:vlan.msgs.portLinkStateUp> Slot-2: Port 1:11 link UP at speed 1 Gbps and full-duplex
02/24/2026 01:24:32.31 <Info:vlan.msgs.portLinkStateUp> Slot-2: Port 1:12 link UP at speed 1 Gbps and full-duplex
02/24/2026 01:24:32.34 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 1:13
02/24/2026 01:24:32.36 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 1:14
02/24/2026 01:24:32.38 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 1:15
02/24/2026 01:24:32.39 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 1:16
02/24/2026 01:24:32.41 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 1:17
02/24/2026 01:24:32.43 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 1:18
02/24/2026 01:24:32.44 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 1:19
02/24/2026 01:24:32.46 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 1:20
02/24/2026 01:24:32.47 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 1:21
02/24/2026 01:24:32.49 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 1:23
02/24/2026 01:24:32.52 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 1:24
02/24/2026 01:24:32.53 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 1:25
02/24/2026 01:24:32.54 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 1:26
02/24/2026 01:24:32.56 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 1:27
02/24/2026 01:24:32.57 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 1:28
02/24/2026 01:24:32.58 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 1:29
02/24/2026 01:24:32.60 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 1:30
02/24/2026 01:24:32.62 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 1:31
02/24/2026 01:24:32.64 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 1:32
02/24/2026 01:24:32.65 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 1:33
02/24/2026 01:24:32.66 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 1:34
02/24/2026 01:24:32.68 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 1:35
02/24/2026 01:24:32.69 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 1:36
02/24/2026 01:24:32.73 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 1:37
02/24/2026 01:24:32.74 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 1:38
02/24/2026 01:24:32.76 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 1:39
02/24/2026 01:24:32.77 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 1:40
02/24/2026 01:24:32.79 <Info:vlan.msgs.portLinkStateUp> Slot-2: Port 1:41 link UP at speed 2.5 Gbps and full-duplex
02/24/2026 01:24:32.81 <Info:vlan.msgs.portLinkStateUp> Slot-2: Port 1:42 link UP at speed 2.5 Gbps and full-duplex
02/24/2026 01:24:32.83 <Info:vlan.msgs.portLinkStateUp> Slot-2: Port 1:43 link UP at speed 2.5 Gbps and full-duplex
02/24/2026 01:24:32.86 <Info:vlan.msgs.portLinkStateUp> Slot-2: Port 1:44 link UP at speed 2.5 Gbps and full-duplex
02/24/2026 01:24:32.88 <Info:vlan.msgs.portLinkStateUp> Slot-2: Port 1:45 link UP at speed 2.5 Gbps and full-duplex
02/24/2026 01:24:32.89 <Info:vlan.msgs.portLinkStateUp> Slot-2: Port 1:46 link UP at speed 2.5 Gbps and full-duplex
02/24/2026 01:24:32.91 <Info:vlan.msgs.portLinkStateUp> Slot-2: Port 1:47 link UP at speed 2.5 Gbps and full-duplex
02/24/2026 01:24:32.93 <Info:vlan.msgs.portLinkStateUp> Slot-2: Port 1:48 link UP at speed 2.5 Gbps and full-duplex
02/24/2026 01:24:32.97 <Info:vlan.msgs.portLinkStateUp> Slot-2: Port 1:50 link UP at speed 10 Gbps and full-duplex
02/24/2026 01:24:33.36 <Info:vlan.msgs.portLinkStateUp> Slot-2: Port 2:14 link UP at speed 1 Gbps and full-duplex
02/24/2026 01:24:33.38 <Info:vlan.msgs.portLinkStateUp> Slot-2: Port 2:15 link UP at speed 100 Mbps and full-duplex
02/24/2026 01:24:33.39 <Info:vlan.msgs.portLinkStateUp> Slot-2: Port 2:16 link UP at speed 100 Mbps and full-duplex
02/24/2026 01:24:33.44 <Info:vlan.msgs.portLinkStateUp> Slot-2: Port 2:17 link UP at speed 1 Gbps and full-duplex
02/24/2026 01:24:33.46 <Info:vlan.msgs.portLinkStateUp> Slot-2: Port 2:18 link UP at speed 100 Mbps and full-duplex
02/24/2026 01:24:33.48 <Info:vlan.msgs.portLinkStateUp> Slot-2: Port 2:19 link UP at speed 1 Gbps and full-duplex
02/24/2026 01:24:33.49 <Info:vlan.msgs.portLinkStateUp> Slot-2: Port 2:20 link UP at speed 1 Gbps and full-duplex
02/24/2026 01:24:33.51 <Info:vlan.msgs.portLinkStateUp> Slot-2: Port 2:21 link UP at speed 1 Gbps and full-duplex
02/24/2026 01:24:33.56 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 2:22
02/24/2026 01:24:33.57 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 2:23
02/24/2026 01:24:33.59 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 2:24
02/24/2026 01:24:33.62 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 2:25
02/24/2026 01:24:33.65 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 2:26
02/24/2026 01:24:33.69 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 2:27
02/24/2026 01:24:33.71 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 2:28
02/24/2026 01:24:33.72 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 2:29
02/24/2026 01:24:33.73 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 2:30
02/24/2026 01:24:33.75 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 2:31
02/24/2026 01:24:33.76 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 2:32
02/24/2026 01:24:33.77 <Info:vlan.msgs.portLinkStateUp> Slot-2: Port 2:33 link UP at speed 100 Mbps and full-duplex
02/24/2026 01:24:33.79 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 2:34
02/24/2026 01:24:33.81 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 2:35
02/24/2026 01:24:33.83 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 2:36
02/24/2026 01:24:33.84 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 2:37
02/24/2026 01:24:33.86 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 2:38
02/24/2026 01:24:33.87 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 2:39
02/24/2026 01:24:33.89 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 2:40
02/24/2026 01:24:33.94 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 2:45
02/24/2026 01:24:33.95 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 2:46
02/24/2026 01:24:33.97 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 2:47
02/24/2026 01:24:33.98 <Info:vlan.dbg.info> Slot-2: Toggling AdminState on Port 2:48
02/24/2026 01:24:34.00 <Info:vlan.msgs.portLinkStateUp> Slot-2: Port 2:50 link UP at speed 10 Gbps and full-duplex
02/24/2026 01:24:36.44 <Info:HAL.Card.Info> Slot-2: Module in Slot-1 is operational
02/24/2026 01:24:40.32 <Info:HAL.Sys.Info> Slot-2: Internal PSU-1 in slot 1 is present.
02/24/2026 01:24:40.32 <Info:HAL.Sys.Info> Slot-2: Input voltage to Internal PSU-1 in slot 1 is on. Output enabled.
02/24/2026 01:24:40.32 <Info:HAL.Sys.Info> Slot-2: Internal PSU-1 in slot 2 is present.
02/24/2026 01:24:40.32 <Info:HAL.Sys.Info> Slot-2: Input voltage to Internal PSU-1 in slot 2 is on. Output enabled.
02/24/2026 01:24:41.59 <Info:vlan.msgs.portLinkStateDown> Slot-2: Port 2:20 link down

02/24/2026 01:24:42.50 <Noti:DM.Notice> Slot-2: Backup is in SYNC
02/24/2026 01:24:43.93 <Info:vlan.msgs.portLinkStateUp> Slot-2: Port 2:20 link UP at speed 1 Gbps and full-duplex
02/24/2026 01:24:56.79 <Info:vlan.msgs.portLinkStateUp> Slot-2: Port 2:41 link UP at speed 2.5 Gbps and full-duplex
02/24/2026 01:24:56.97 <Info:vlan.msgs.portLinkStateUp> Slot-2: Port 2:42 link UP at speed 2.5 Gbps and full-duplex
02/24/2026 01:24:57.34 <Info:vlan.msgs.portLinkStateUp> Slot-2: Port 2:43 link UP at speed 2.5 Gbps and full-duplex
02/24/2026 01:24:57.63 <Info:vlan.msgs.portLinkStateUp> Slot-2: Port 2:44 link UP at speed 2.5 Gbps and full-duplex
02/24/2026 01:25:07.78 <Info:vlan.msgs.portLinkStateDown> Slot-2: Port 2:41 link down
02/24/2026 01:25:08.27 <Info:vlan.msgs.portLinkStateDown> Slot-2: Port 2:43 link down
02/24/2026 01:25:09.43 <Info:vlan.msgs.portLinkStateDown> Slot-2: Port 2:42 link down
02/24/2026 01:25:09.89 <Info:vlan.msgs.portLinkStateDown> Slot-2: Port 2:44 link down
02/24/2026 01:25:17.34 <Info:vlan.msgs.portLinkStateDown> Slot-2: Port 2:20 link down
02/24/2026 01:25:19.75 <Info:vlan.msgs.portLinkStateUp> Slot-2: Port 2:20 link UP at speed 1 Gbps and full-duplex
02/24/2026 01:25:20.07 <Erro:HAL.IPv4Mc.Error> Slot-2: Unable to Del L2 2:50 from s,G,v=0,effffffa,1201 IPMC 7 vp 0 ecid 0x0, unit 0 Entry not found
02/24/2026 01:25:39.07 <Erro:HAL.IPv4Mc.Error> Slot-2: Unable to Del L2 2:50 from s,G,v=0,effffffa,1001 IPMC 3 vp 0 ecid 0x0, unit 0 Entry not found
02/24/2026 01:25:55.13 <Info:vlan.msgs.portLinkStateUp> Slot-2: Port 2:41 link UP at speed 2.5 Gbps and full-duplex
02/24/2026 01:25:57.33 <Info:vlan.msgs.portLinkStateUp> Slot-2: Port 2:43 link UP at speed 2.5 Gbps and full-duplex
02/24/2026 01:25:57.49 <Info:vlan.msgs.portLinkStateUp> Slot-2: Port 2:42 link UP at speed 2.5 Gbps and full-duplex
02/24/2026 01:25:57.89 <Info:vlan.msgs.portLinkStateUp> Slot-2: Port 2:44 link UP at speed 2.5 Gbps and full-duplex

Re: 4220 stacking stability

Necheporenko__N — Fri, 27 Mar 2026 09:09:16 GMT

You have next lines in the log

02/24/2026 01:25:20.07 <Erro:HAL.IPv4Mc.Error> Slot-2: Unable to Del L2 2:50 from s,G,v=0,effffffa,1201 IPMC 7 vp 0 ecid 0x0, unit 0 Entry not found
02/24/2026 01:25:39.07 <Erro:HAL.IPv4Mc.Error> Slot-2: Unable to Del L2 2:50 from s,G,v=0,effffffa,1001 IPMC 3 vp 0 ecid 0x0, unit 0 Entry not found

Both indicate on an issue with mcast ip == 239.255.255.250 (hex == ef.ff.ff.fa), also there might be a lot of LLMNR streams which are not blocked by your ACL.

Please check next article for better understanding on which mcast streams you need to pay your attention.

https://extreme-networks.my.site.com/ExtrArticleDetail?an=000080382

Re: 4220 stacking stability

Brent_Addis — Mon, 13 Apr 2026 21:56:14 GMT

Thanks for that. It's predominantly mDNS traffic caused by end devices we don't have control over (It's a large campus with 5-10k devices daily). Xbox and other devices have a lot to answer for, especially now that mDNS is used so heavily by latest releases of windows 11.

I have enabled IGMP snooping across all fabricengine devices on only affected isids/vlans, including the core which seems to has resolved the issue. Been stable for a few weeks now. Switchengine has igmp snooping enabled across all ports already, however as it's fabric attach upstream is fabricengine it was still getting floods.

topic Re: 4220 stacking stability in ExtremeSwitching (EXOS/Switch Engine)

4220 stacking stability

Re: 4220 stacking stability

Re: 4220 stacking stability