SSH connection to one device stalls

Hello everyone,

I've been having a strange problem for a while now, that I would like to troubleshoot.

I'm using two MediaTek MT7615 devices: One dumb access point and one router. Everything is running perfectly, except for one strangeness: Using my Windows computer, SSH connections (using Putty) to a single-board Odroid device stall, when the Windows computer is connected to the network using Wifi.

The connection behaves similar to MTU issues: It stalls and timeouts in different time intervals. SCP, for example, is now problem. Wired SSH connections are no problem. Wireless connections to other Linux based devices are no problem.

I'm not sure this is a OpenWRT issue. But I would be glad for any pointers!

I'd start looking for errors in the interfaces stats, before digging deeper into packet captures to understand where is the delay.

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Thanks for your reply! Where would I find the interface stats in Windows / Linux, typically? Windows' event log has no entries for the network adapter.

See: https://www.reddit.com/r/sysadmin/comments/7blzws/how_to_find_windows_network_errors/?utm_source=share&utm_medium=web2x&context=3

  • All interfaces: ip -s link show
  • Individual interfaces: ip -s link show <interface_name>

Reference: https://linux.die.net/man/8/ip

(Found by web search.)

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Thank you very much. Network adapters on both sides show no errors.

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Then try to capture the ssh packets:
opkg update; opkg install tcpdump <-if you have not installed it yet.

Then capture ssh packets only for the Odroid.
tcpdump -i any -vn tcp port 22 and host 10.0.0.1
replace the IP with the one from Odroid and try to connect to it from your desktop.
After you are connected end the capture with Ctrl-c and paste the output here.

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