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Comment by remuskaos | Hacker News Reader

I think they actually did manage to fuck up even the small unmanaged switches. I have three unmanaged switches at home, one on the ground floor and two in the first floor. Ground floor is an 8 port netgear, first floor are one to link and one d link.

Every couple of weeks, the entire wired network goes down. Not even pinging adresses works. The d links ports leds are all flashing (perfectly in sync!) until I power cycle it. Then everything goes back to normal.

I have no idea what happens, and I should probably replace the d link soon.

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Are you aware about broadcast storms? Perhaps you somehow accidentally introduced a loop in the network? The symptoms fit that exactly. https://en.wikipedia.org/wiki/Broadcast_storm

STP is meant to prevent that. https://en.wikipedia.org/wiki/Spanning_Tree_Protocol

Of course you can't set up STP with unmanaged switches, so until you go managed and set up STP properly nothing will change.

It could be missing IGMP Snooping Protocol support in a network with IPTV or custom VLAN setups. There are 3 versions (IGMP snooping (v1, v2, and v3)), managed switches have them all, unmanaged usually don't have them. To avoid problems, only pass a single VLAN to the unmanaged switch (it must be behind the managed switch for that), otherwise the unmanaged switch can and usually will bring a network down after some time. Or just use a switch with IGMP snooping support.

I was not! Thanks for the hint!

Although I'm 100% sure there are no loops, I haven't changed the actual cable layout in ages.

If the D-link has a wall wart which you could easily replace, try that. (And maybe a real surge strip, if you've got one handy.) Iffy power can cause all sorts of bizarre behavior.

I have a couple of TP-Link unmanaged 4 port SOHO switches. They're pretty reliable so far.

The TP Link (typo in my other post) and the Netgear are reliable, only the D Link causes issues.

Jumbo frames? https://en.m.wikipedia.org/wiki/Jumbo_frame

I haven't enabled jumbo frames knowingly on my system, but even if I had, why would the issue occur only every few weeks? Also, it seems to be rather independent of the actual network load.

A friend had networked speakers that would freeze until a manual reboot time to time. It turned out to be the Linux running within the speakers that crashed on the occasional jumbo frame.

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