# Connection to router suddenly fails

## matsu

It has happened four times over the last two weeks that the router connection would suddenly fail and that there was no possibility to regain connection. Neither restarting the router nor dhcpcd restart would solve the problem, only after rebooting my computer I could connect to the router again.

Before happening I didn't do anything worth mentioning, and I cannot remember having changed my system two weeks ago except for some updates including a kernel update.

This has never happend before in those years I have been using Gentoo.

Any ideas what could have happened here or what I could look for the next time it will happen (as it didn't look really random to me)?

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## Alex_ir

What are you see with "ifconfig" in this moment ? Can are you see your MAC address on your router ?

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## matsu

Unfortunately, I didn't think about ifconfig then, so I don't know the output.

I only know that "route -n" showed the same route as usual.

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## Maitreya

It's going to be very hard to diagnose if the problem can't be replicated.

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## matsu

I am aware that it is impossible to diagnose now.

I just don't know what to do for error diagnosis (like said "ifconfig -a" which I didn't think about), which outputs I will need, when it will happen again, because I won't have internet connection to be able to ask here.

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## krinn

dmesg is your friend for network error message.

And you should try to just unload and reload the network card module instead of rebooting, ease the pain.

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## jamapii

To diagnose, you can use outputs of "ifconfig" and "route -n", also "iwconfig" if it's wlan.

To do the (kernel) module reloading, the networking kernel driver must be a module (not compiled-in), and you must know the module's name (lsmod should help, and "lspci -v"). When it happens, after you've gathered diagnostic data, you can rmmod and modprobe it, just for testing. This will create more dmesg output and maybe it works again.

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