Question : Random port flapping on Netgear 7248

Hi guys,  I'm having some issues with our Netgear 7248 switches...  Since a power outage earlier in the week I'm getting random and repeated port disconnect/reconnects on three different switches.  Devices connected to these ports are mostly PCs, however one WAP is bouncing as well.  I don't see any indication on the PC's that the OS is aware of the fluctuating network state.  All the switches have been restarted, and speed between them is very good.  Have any of you seen anything like this?  Here is a sample of one of the logs...


<5> Jan 1 02:37:49 192.168.103.251-1 TRAPMGR[289603800]: traputil.c(663) 428 %% Link Up: Unit: 1 Slot: 0 Port: 1  
<5> Jan 1 02:37:47 192.168.103.251-1 TRAPMGR[289603800]: traputil.c(663) 427 %% Link Down: Unit: 1 Slot: 0 Port: 1  
<5> Jan 1 02:36:09 192.168.103.251-1 TRAPMGR[289603800]: traputil.c(663) 426 %% Link Up: Unit: 1 Slot: 0 Port: 1  
<5> Jan 1 02:36:07 192.168.103.251-1 TRAPMGR[289603800]: traputil.c(663) 425 %% Link Down: Unit: 1 Slot: 0 Port: 1  
<5> Jan 1 02:33:55 192.168.103.251-1 TRAPMGR[289603800]: traputil.c(663) 424 %% Link Up: Unit: 1 Slot: 0 Port: 1  
<5> Jan 1 02:33:53 192.168.103.251-1 TRAPMGR[289603800]: traputil.c(663) 423 %% Link Down: Unit: 1 Slot: 0 Port: 1  
<5> Jan 1 02:32:20 192.168.103.251-1 TRAPMGR[289603800]: traputil.c(663) 422 %% Link Up: Unit: 1 Slot: 0 Port: 1  
<5> Jan 1 02:32:18 192.168.103.251-1 TRAPMGR[289603800]: traputil.c(663) 421 %% Link Down: Unit: 1 Slot: 0 Port: 1  
<5> Jan 1 02:30:07 192.168.103.251-1 TRAPMGR[289603800]: traputil.c(663) 420 %% Link Up: Unit: 1 Slot: 0 Port: 1  
<5> Jan 1 02:30:05 192.168.103.251-1 TRAPMGR[289603800]: traputil.c(663) 419 %% Link Down: Unit: 1 Slot: 0 Port: 1  
<5> Jan 1 02:28:34 192.168.103.251-1 TRAPMGR[289603800]: traputil.c(663) 418 %% Link Up: Unit: 1 Slot: 0 Port: 1  
<5> Jan 1 02:28:33 192.168.103.251-1 TRAPMGR[289603800]: traputil.c(663) 417 %% Link Down: Unit: 1 Slot: 0 Port: 1  
<5> Jan 1 02:26:21 192.168.103.251-1 TRAPMGR[289603800]: traputil.c(663) 416 %% Link Up: Unit: 1 Slot: 0 Port: 1  
<5> Jan 1 02:26:18 192.168.103.251-1 TRAPMGR[289603800]: traputil.c(663) 415 %% Link Down: Unit: 1 Slot: 0 Port: 1  
<5> Jan 1 02:25:05 192.168.103.251-1 TRAPMGR[289603800]: traputil.c(663) 414 %% Link Up: Unit: 1 Slot: 0 Port: 29  
<5> Jan 1 02:25:04 192.168.103.251-1 TRAPMGR[289603800]: traputil.c(663) 413 %% Link Down: Unit: 1 Slot: 0 Port: 29  
<5> Jan 1 02:24:51 192.168.103.251-1 TRAPMGR[289603800]: traputil.c(663) 412 %% Link Up: Unit: 1 Slot: 0 Port: 1  
<5> Jan 1 02:24:50 192.168.103.251-1 TRAPMGR[289603800]: traputil.c(663) 411 %% Link Down: Unit: 1 Slot: 0 Port: 1  
<5> Jan 1 02:22:39 192.168.103.251-1 TRAPMGR[289603800]: traputil.c(663) 410 %% Link Up: Unit: 1 Slot: 0 Port: 1  
<5> Jan 1 02:22:36 192.168.103.251-1 TRAPMGR[289603800]: traputil.c(663) 409 %% Link Down: Unit: 1 Slot: 0 Port: 1  
<5> Jan 1 02:20:39 192.168.103.251-1 TRAPMGR[289603800]: traputil.c(663) 408 %% Link Up: Unit: 1 Slot: 0 Port: 1  
<5> Jan 1 02:20:37 192.168.103.251-1 TRAPMGR[289603800]: traputil.c(663) 407 %% Link Down: Unit: 1 Slot: 0 Port: 1  
<5> Jan 1 02:18:26 192.168.103.251-1 TRAPMGR[289603800]: traputil.c(663) 406 %% Link Up: Unit: 1 Slot: 0 Port: 1  
<5> Jan 1 02:18:23 192.168.103.251-1 TRAPMGR[289603800]: traputil.c(663) 405 %% Link Down: Unit: 1 Slot: 0 Port: 1  
<5> Jan 1 02:16:31 192.168.103.251-1 TRAPMGR[289603800]: traputil.c(663) 404 %% Link Up: Unit: 1 Slot: 0 Port: 1  
<5> Jan 1 02:16:29 192.168.103.251-1 TRAPMGR[289603800]: traputil.c(663) 403 %% Link Down: Unit: 1 Slot: 0 Port: 1  
<5> Jan 1 02:14:12 192.168.103.251-1 TRAPMGR[289603800]: traputil.c(663) 402 %% Link Up: Unit: 1 Slot: 0 Port: 1  
<5> Jan 1 02:14:10 192.168.103.251-1 TRAPMGR[289603800]: traputil.c(663) 401 %% Link Down: Unit: 1 Slot: 0 Port: 1  
<5> Jan 1 02:12:15 192.168.103.251-1 TRAPMGR[289603800]: traputil.c(663) 400 %% Link Up: Unit: 1 Slot: 0 Port: 1  
<5> Jan 1 02:12:14 192.168.103.251-1 TRAPMGR[289603800]: traputil.c(663) 399 %% Link Down: Unit: 1 Slot: 0 Port: 1  
<5> Jan 1 01:55:24 192.168.103.251-1 TRAPMGR[289603800]: traputil.c(663) 398 %% Link Up: Unit: 1 Slot: 0 Port: 29  
<5> Jan 1 01:55:20 192.168.103.251-1 TRAPMGR[289603800]: traputil.c(663) 397 %% Link Down: Unit: 1 Slot: 0 Port: 29  
<5> Jan 1 01:47:17 192.168.103.251-1 TRAPMGR[289603800]: traputil.c(663) 396 %% Link Up: Unit: 1 Slot: 0 Port: 9  
<5> Jan 1 01:47:15 192.168.103.251-1 TRAPMGR[289603800]: traputil.c(663) 395 %% Link Down: Unit: 1 Slot: 0 Port: 9  
<5> Jan 1 01:46:25 192.168.103.251-1 TRAPMGR[289603800]: traputil.c(663) 394 %% Link Up: Unit: 1 Slot: 0 Port: 9  
<5> Jan 1 01:46:24 192.168.103.251-1 TRAPMGR[289603800]: traputil.c(663) 393 %% Link Down: Unit: 1 Slot: 0 Port: 9  


Any comments would be appreciated.

Thanks,

John

Answer : Random port flapping on Netgear 7248

Up/down problems could be from damaged firmware.  Have you already backed up and tried to refresh or update the firmware?

We had a similar situation where one port died.  Then another...and another.  We had to shuffle ports until it stopped with 8 ports gone.

If we replaced with clean firmware and default configuration, all ports worked fine.

As soon as we re-loaded our configuration, the ports started dying again.  We ended up updating firmware to current, then re-building the configuration as close as possible to the old.  Helps if you have documentation (human-readable!) of how/why the switch is configured.  Especially routing, VLANs, LAGs, etc.