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nap n00b
Joined: 18 Aug 2017 Posts: 10
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Posted: Sun Nov 12, 2017 4:16 pm Post subject: [SOLVED] SSH Refused due to WiFi net.wlan0 misconfiguration |
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I have a bit of a problem with accessing my robot using SSH, even though I'm using a wired connection.
The problem relates to my efforts to get the robot to automatically connect on WiFi. I added a symlink net.wlan0 that points to net.lo, and it worked. However, on the next boot, ifconfig showed that wlan0 did not exist. So I thought I would add it to the boot run-level 'rc-update add net.wlan0 boot'. But, now I cannot even log into the robot using the wired connection: I get a "connection refused" response.
The root partition is an embedded storage device and I only have access to the "User data" part which is stored on a micro-SD and includes some system files.
I'm wondering if:
1) There is a way of arranging a script to run from one of the following folders on boot up that would remove net.wlan0 from boot (ie remove the symlink)?
On the micro-SD, I have access to the following paths:
/etc /etc/ssh /etc/connman (and the following files: babile.conf, hostname, localtime, resolve.conf, shadow)
/home (I have access to the entire home area, but the user has no sudo rights)
/lost+found
/media
/var /var/lib (inside lib, I have ./alsa ./bluetooth ./connman ./dbus ./dhcp ./firewall_mode ./gentoo ./iptables ./lib ./minidump ./misc ./ntp ./packagemanager ./portage ./store) /var/lib/lib/ofono
2) Since some of these folders/files are system related, I'm wondering if it's possible place something into /etc/runlevels/boot to invalidate the symlink that rc-update put there?
3) Any ideas on how I can persuade SSHD to accept my connection? (Telnet? Though I don't think it's running a daemon.)
Cheers,
Nap
Last edited by nap on Fri Dec 08, 2017 1:52 pm; edited 1 time in total |
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mike155 Advocate
Joined: 17 Sep 2010 Posts: 4438 Location: Frankfurt, Germany
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Posted: Sun Nov 12, 2017 5:04 pm Post subject: |
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If I understand your post correctly, you have two separate problems:
- your wlan interface doesn't come up after boot
- even if your interface is up, you get a "connection refused" when you want to connect to your robot
I can't help you with the first problem.
Regarding the second problem: if your SSH client tells you "Connection refused", this usually means it can establish a TCP/IP connection to your robot, but there is no SSH daemon listening on the SSH port. The most common reasons for that are: either the SSH daemon isn't running or it is not configured to listen on your interface. Look at the file /etc/ssh/sshd_config: are there any non-standard settings for the configuration variables "Listen" or "Port"? |
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nap n00b
Joined: 18 Aug 2017 Posts: 10
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Posted: Tue Nov 14, 2017 6:52 am Post subject: |
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Hi Mike155, there is a ssh daemon running, to which I was connecting over wired ethernet. However, it is possible that the daemon is crashing during boot-up as a result of my setting the net.wlan0 to be a boot level service. Unfortunately, I cannot check settings since I cannot log in via SSH. |
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charles17 Advocate
Joined: 02 Mar 2008 Posts: 3664
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Posted: Tue Nov 14, 2017 7:24 am Post subject: Re: SSH Refused due to WiFi net.wlan0 misconfiguration |
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nap wrote: | I have a bit of a problem with accessing my robot using SSH, even though I'm using a wired connection.
The problem relates to my efforts to get the robot to automatically connect on WiFi. I added a symlink net.wlan0 that points to net.lo,... |
nap wrote: | ... On the micro-SD, I have access to the following paths:
/etc /etc/ssh /etc/connman |
Are you mixing setup of two different network managers? |
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nap n00b
Joined: 18 Aug 2017 Posts: 10
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Posted: Fri Dec 08, 2017 1:51 pm Post subject: |
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I've solved the problem by accessing the robot via its serial console (FTDI chip).
The problem was that I had created a boot level service for net.wlan0 and that was crashing the SSH daemon on boot up. Through the serial console, I was able to delete the net.wlan0 symlink in /etc/runlevels/boot and everything was fine on the next boot.
Thanks for the suggestions. |
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