dhcpcd: wlan0: is unreachable, expiring it

epg · 05-21-2019, 10:53 AM

Hi,

Since a few days ago I've been having some hicups when connected to my home wifi, meaning: suddenly my PC freezes and I ahve to disconnect and reconnect on wicd. It's been happening a few times a day and all other devices connected to the same wifi are doing fine, I haven't noticed any issues anywhere else so I think the problem is in my PC.

/var/log/syslog says this:

May 21 08:26:21 pc-hp dhcpcd[13615]: wlan0: fe80::250:f1ff:fe80:0 is unreachable, expiring it
May 21 08:26:32 pc-hp dhcpcd[13615]: wlan0: fe80::250:f1ff:fe80:0 is unreachable, expiring it
May 21 08:27:52 pc-hp last message repeated 5 times
May 21 08:28:03 pc-hp dhcpcd[13615]: wlan0: fe80::250:f1ff:fe80:0 is unreachable, expiring it

I'll see if this happens also on other wifi networks, haven't had a chance to test that yet.

Running Slackware 14.2, latest updates installed.

Any ideas? So far I haven't found useful references to this error log...

Thank you!

ondoho · 05-21-2019, 01:47 PM

the pc freeze would suggest that this isn't a wifi problem.
can you please troubleshoot what causes the pc freeze.

business_kid · 05-21-2019, 01:51 PM

When it's connected, what does this show?

Code:

sudo iwconfig wlan0

Next, you could try this one and if all your neighbours are on the same channel as you, get off it

Code:

sudo iwlist wlan0 scan |grep -e 'Channel' -e 'ESSID' -e 'Quality'

epg · 05-21-2019, 01:55 PM

I'm sorry, I just realized I was VERY unclear in my description... When I say the PC freezes, I meant network-wise. I can't go anywhere, not even ping to the default gateway succeeds...

It's happening more and more often. I had to disconnect/reconnect 5 or 6 times in the last 4 hours to fix this.

scasey · 05-21-2019, 03:08 PM

Just a thought:
Is there a duplicate IP address on the network?

epg · 05-22-2019, 12:19 PM

Quote:

Originally Posted by scasey

Just a thought:
Is there a duplicate IP address on the network?

Yeah, good idea but no, no duplicates...

epg · 05-23-2019, 01:04 PM

Quote:

Originally Posted by business_kid

When it's connected, what does this show?

Code:

sudo iwconfig wlan0

Next, you could try this one and if all your neighbours are on the same channel as you, get off it

Code:

sudo iwlist wlan0 scan |grep -e 'Channel' -e 'ESSID' -e 'Quality'

Thank you for your reply. I've been monitoring for the last couple of days and the issue just didn't reproduce... Anyway, I ran iwconfig:

bash-4.3# iwconfig wlan0
wlan0 IEEE 802.11abgn ESSID:"Net"
Mode:Managed Frequency:2.437 GHz Access Point: AA:AA:AA:AA:AA:AA
Bit Rate=144.4 Mb/s Tx-Power=22 dBm
Retry short limit:7 RTS thr

ff Fragment thr

ff
Encryption key

ff
Power Management

ff
Link Quality=54/70 Signal level=-56 dBm
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:399 Missed beacon:0

I'll check this whenever the network freezes again. Maybe it was just interference?

business_kid · 05-24-2019, 03:54 AM

I was in tvs in the 1970s here, and we in Ireland had a lot of traffic in weak signals as we were pinching signals meant for our Britain and as far as possible not for us. Crazy things affect signal strength - damp, ruffled service on rebound areas, and obstacles to direct path, aerial orientation, etc. Often, moving around helps. That's a very healthy set of figures in your iwconfig o/p, better than mine in most cases. If it's only been connected a short while, the "Invalid misc" is a bit high, but it's otherwise fine.