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Port connected to router randomly becomes disabled
I have had this switch for about three months now, it works well expect that the port connected to router would randomly becomes disabled.
The router assigned 192.168.1.100 to the switch, which is different from the default IP address. I don't think this would make a difference.
Anyone has any idea why this is happening?
I have changed the cable (both new and old were Cat6a), and not difference. Is there a setting that we need configure in the router or switch?
Right now, we have to either re-enable the port in the admin console or soft/hard restart the switch, but the port would becoming disabled after a few hours or up to a few days. Not sure what is causing the variance.
Re: Port connected to router randomly becomes disabled
Sorry for that issue, but it seems that a constant DoS attack propagating from the router is mitigated by the switch with either Auto-Dos feature (please configure it here: System Management Denial of Service Auto-DoS Configuration.) or DoS configuration feature (please configure it here: System Management Denial of Service Denial of Service Configuration.).
Maybe because of your NAS services accessible from the internet or a Dos attack against your router, the switch is trying to protect your network. Please can you test and de-activate Auto-DoS in above GUI page, and ultimately configure DoS differently in the other GUI page and let the Community know the results?
Re: Port connected to router randomly becomes disabled
Hi JohnCarloV,
Actually, I had opened a case with Netgear support before. So we have gone through the typical steps of troubleshooting, include updating to the latest firmware, chaging cable, changing ports, factory reset/reimport settings. However, none of that worked.
In fact, one workaround I have been using is just moving the cable from the router to another open port, but then after a while that port would become disabled as well. So, I will have to reenable in the console or soft/hard restart the switch.
The Netgear support was very unhelpful, as they just blame our router for being the issue and throw their hands in the air. Hence, I have create this thread to get help from the community.
Re: Port connected to router randomly becomes disabled
Hi John,
Is there potentially a loop from the other network/network devices connected to the XS for example to the router or another wireless, for example by some media player?
What does the XS log show about the reason for the uplink port becoming disabled?
Re: Port connected to router randomly becomes disabled
Hi schumaku,
Initially, when we worked with support, they found the log to be reporting discarding Invalid BPDUs, so they recommended us to disable spanning tree. It did get rid of the errors in the log, however, this did not resolve this issue.
Please see attached our network topology. It's quite simple, not sure why the loop might be. One thing to note is that our new NAS, the Synology DS3617XS has DDNS setup (ports forwarded in the router), so it is accessiable through the internet.
I don't have access to the switch right now, but once I do, I will share the log.
<11> Sep 15 17:29:22 -1 DOS[dtlTask]: dos_api.c(1844) 341 %% Interface xg9 has been shutdown by DOS attack notification.
Looks like my router got DOS attack and trickled down to the switch. However, the router does have Firewall and DoS protection enabled. Is there something that I need to do on the router side or on the switch side?
Re: Port connected to router randomly becomes disabled
No, that's part of the DoS capabilities on the switch, there is no "notification" layer for DoS between network components - check the configuration, it's either Auto-DoS, or some custom config. I would expect there would be some more information in the logs ref. DoS before the automatic shutdown.
Re: Port connected to router randomly becomes disabled
I just check, it's on Auto-DoS. I checked again, there's nothing before the port shutdown. I setup a log server, so the log entries will be perserved even after switch reset. Let's see what show's up in the next episode.
Re: Port connected to router randomly becomes disabled
it ready very wrong to me that this user's switch does shut down a port claiming "dos_api.c(1844) 341 %% Interface xg9 has been shutdown by DOS attack notification." without any log details what kind of DoS (not DOS please...) triggered the notification. Please investigate and assist.
Re: Port connected to router randomly becomes disabled
Sorry for that issue, but it seems that a constant DoS attack propagating from the router is mitigated by the switch with either Auto-Dos feature (please configure it here: System Management Denial of Service Auto-DoS Configuration.) or DoS configuration feature (please configure it here: System Management Denial of Service Denial of Service Configuration.).
Maybe because of your NAS services accessible from the internet or a Dos attack against your router, the switch is trying to protect your network. Please can you test and de-activate Auto-DoS in above GUI page, and ultimately configure DoS differently in the other GUI page and let the Community know the results?
