Issue with ping and opkg update on Beaglebone black - networking

I'm new with BeagleBone Black, i'm using Angstrom default distro, often i have trouble with ping,opkg update and ssh.
BeagleBone Black has 2 Network Interface, the virtual one (On USB) and the phisical eth0.
I can connect with SSH only with the USB ip, in the other i obtain:
Write failed: Broken pipe
And I've seen a lot of problems during ping and during opkg update.
OPKG stay sometimes undefinitly on this screen:
Downloading http://feeds.angstrom-distribution.org/feeds/v2012.12/ipk/eglibc/armv7a-vfp-neon/base/Packages.gz.
With no results.
And Ping often can't resolve ping to google.it
Someone had similar issues?
Thanks

I ran into a similar issue, this thread might prove helpful in fixing the opkg update problem. Most of the people in that thread do some variation of the following:
Boot your BBB and log in via SSH.
Edit /etc/resolv.conf to add Google's public DNS server:
# cat "nameserver 8.8.8.8" >> /etc/resolv.conf
Run
# route add default gw 192.168.7.1
Run opkg update and upgrade:
# opkg update
# opkg upgrade
Keep in mind, that your changes to the /etc/resolv.conf file will be lost at reboot. I have yet to investigate why.

Related

Amazon EC2 Ubuntu 20 - DNS resolution doesn't work

I posted my solution too. I hope this saves someone else a lot of time.
I have an EC2 instance running Ubuntu 20. DNS resolution never works, or fails a lot.
My file /etc/resolv.conf has
nameserver 127.0.0.53
The file is not a symlink, and I can certainly edit it to use nameserver 8.8.8.8 ,
But the file periodically gets overwritten and the 127.0.0.53 (or something similar) is back.
I just want dns to work!
See my solution below.
Get your nic's name from a config file.
cat /etc/netplan/50-cloud-init.yaml
On my system, amazon sets the nic name to ens5.
As root create new file: /etc/netplan/99-custom-dns.yaml
with the following content.
Replace ens5 with your nic's name.
network:
version: 2
ethernets:
ens5:
nameservers:
addresses: [8.8.8.8]
dhcp4-overrides:
use-dns: false
Reboot
sudo shutdown -r now
Verify. After the reboot you can try pinging something by name
ping yahoo.com
or you can view the output of:
systemd-resolve --status
Done
Here's a link to the Amazon help doc, though it misses the nontrivial detail about your nic's name:
https://aws.amazon.com/premiumsupport/knowledge-center/ec2-static-dns-ubuntu-debian/

VPN killswitch using UFW, but now openvpn3 no longer can start automatically

I successfully implemented this, which blocks all internet connections on my Linux machine UNLESS it connects via a specific VPN :
https://www.comparitech.com/blog/vpn-privacy/how-to-make-a-vpn-kill-switch-in-linux-with-ufw/
If I manually execute openvpn3 session-start --config ~/Desktop/config.ovpn, it successfully connects via the VPN.
I used to have this command in a script (that has #!/bin/bash as header) which ran at device bootup without any issues, UNTIL I configured ufw for the killswitch above (now ufw runs on device bootup).
I use openvpn3 so using instructions in the above tutorial for openvpn commands didn't work at all.
I even tried using a sleep in my bash script to get it to wait a while until after bootup. Doesn't work. But if I issue the connection command manually in the command prompt, it works.
Please help! I need it to connect automatically. Much appreciated!
After spending a whole day on this, I figured out a solution. I found an article that guided me : https://www.howtogeek.com/687970/how-to-run-a-linux-program-at-startup-with-systemd/
I set up a service item using systemd (systemctl) just for that command to connect. Here is what my entry looks like :
#/etc/systemd/system/connectvpn.service
[Unit]
Description=Connect VPN
After=ufw.service network.target
Requires=ufw.service
[Service]
Type=oneshot
ExecStart=/usr/local/bin/connect
#/usr/local/bin/connect
#!/bin/bash
openvpn3 session-start --config /home/xyz/Desktop/config.ovpn
Working nicely now, connects to the VPN on bootup.

mount.nfs: requested NFS version or transport protocol is not supported

NFS Mount is not working in my RHEL 7 AWS instance.
When I do a
mount -o nfsvers=3 10.10.11.10:/ndvp2 /root/mountme2/
I get the error:
mount.nfs: requested NFS version or transport protocol is not supported
Can anyone point me where I am wrong?
Thanks.
Check the nfs service is started or reboot the nfs service.
sudo systemctl status nfs-kernel-server
In my case this package was not running and the issue was in /etc/exports file where i was having same IP address for two machines.
So i commented one ip address for the machine and restarted nf-kernel-server using
sudo systemctl restart nfs-kernel-server and reload the machine.
It worked.
A precision which might be useful for the dump (like me): systemctl status nfs-server.service and systemctl start nfs-server.service must be executed on the server!
Some additional data
If, like me, you've deleted a VM without shutting it down right you might also need to manually edit the file /etc/exports because NFS is trying to connect to it and fails but doesn't continue with the next, it just dies.
After that you can manually restart as mentioned in other answers.
In my case, a simple reload didn't suffice. I had to perform a full restart:
sudo systemctl status nfs-kernel-server
In my case, it didn't work correctly with version NFS 4.1.
So in Vargantfile in each place where is type: 'nfs' I added coma and nfs_version: 4, nfs_udp: false
Here is more detailing explanation NFS
If you're giving a specific protocol to connect with, also check to make sure your NFS server has that protocol enabled.
I got this error when trying to start up a Vagrant box, and my nfs server was running. It turns out that the command Vagrant uses is:
mount -o vers=3,udp,rw,actimeo=1 192.168.56.1:/dir/on/host /vagrant
Which specifically asks for UDP. My server was running but it was not configured to enable connecting over UDP. After consulting /etc/nfs.conf, I created /etc/nfs.conf.d/10-enable-udp.conf with the following contents to enable udp:
[nfsd]
udp=y
The name of the file doesn't matter, as long as it's in the conf.d directory and ends in .conf. Depending on your distribution it may be configured differently. You can directly edit nfs.conf, but using a conf.d file is more likely to preserve the changes after upgrading your system.
Try to ping IP address of the server "ping " from client "ping , if you get reply then install nfs server on the host. Then edit /etc/exports file don't forget to add port along with IP address
I got the solution: make an entry in nfs server /etc/nfsmount.conf with Defaultvers=3 .
There will # Defaultvers=3 just unhash it and then mount on nfs client.
Issue will be resolved!

opensuse network management undefined

I did an update on my opensuse box and networking stopped working. The system is trying to use networkmanager, even though it isn't installed. I am using yast to try and get it to use ifup, but it complains about no network connection. I tried running:
ifup eth0
and I get back:
Network is managed by '' -> skipping
Does anyone out there know why it is coming back empty and if there is a config file that I can manually tweak to fix this?
I'm assuming you are running 12.3 or 13.1 with systemd.
Disable network manager if it exists:
systemctl disable networkmanager.service
Enable network.service:
systemctl enable network.service
Make sure ifcfg-eth0 exists with a configuration in /etc/sysconfig/network/
Run ifup eth0
Hope this will help someone.
1. Disable NetworkManager, Stop is and then enable it and restart it respectively.
2. All this happens in console. Check the status for NetworkManager and in the status messages it should show that the interface(wierless) is disconnected. Confirm this by typing command "sudo nmcli c"
3. Type command "sudo iwlist (wireless-interface) scan" to show you the available wireless networks
4. If you see the network that you want to connect to listed, type command "nmcli a" and enter the corresponding connect phrase/password to connect

Cannot connect to beaglebone.local

I need to know how to connect to a beaglebone (or beagleboard) with SSH when I plug it into a new network with an ethernet cable like this:
$ ssh root#beaglebone.local
So far I've only been able to access it like this, if I know the IP address:
$ ssh root#<ip_address>
But I don't always know the IP address of the board on new networks so I'm hoping to access it with with a name like: beaglebone.local.
Right now when I try to do this I get this error:
"ssh: Could not resolve hostname beaglebone.local: nodename nor servname provided, or not known"
I checked the hostname and hosts files, and added "127.0.0.1 beaglebone" to the hosts on the beaglebone, but not sure what else I can do?
# cat /etc/hostname
beaglebone
# cat /etc/hosts
127.0.0.1 localhost.localdomain localhost
127.0.0.1 beaglebone
I had a similar issue running my beaglebone on Angstrom-Cloud9-IDE-GNOME-eglibc-ipk-v2012.05-beaglebone-2012.04.22.img.xz. In this distribution, "beaglebone.local" should appear on the network after the system boots.
About 50% of the time after reboot, "beaglebone.local" would not appear on the network (although the bone would be available by IP address). When this happened, "systemctl status avahi-daemon.service" showed that the avahi-daemon failed with "exit code 255". Interestingly, a subsequent "systemctl start avaihi-daemon.service" would always be successful and "beaglebone.local" would appear on the network.
Also "journalctl | grep avahi" returned a single message stating something like "Daemon already runnin gon PID NNN".
So, I "fixed" the problem by adding the line "ExecStartPre=/bin/rm -f /var/run/avahi-daemon/pid" to the [Service] section of /lib/systemd/system/avahi-daemon.service. With this addition, "beaglebone.local" now appears on the network 100% of reboots.
I say "fixed" (i.e., in quotes) because I have not been able to track down the root cause that is leaving around the stray avahi pid file(s) and thus don't have a true fix.
-- Frank
For 'beaglebone.local' to work, your host machine must recognize Zeroconf. The BeagleBone uses Avahi to tell other systems on the LAN that it is there and serving up applications and that it should be called a 'beaglebone'. If there are more than one, the second one is generally called 'beaglebone-2.local'.
I hate answering my own questions. The following hack will work until a better way emerges:
This shell script (where xxx.xxx.xxx is the first three numbers in your computer's IP) will find your beaglebone or beagleboard (that is plugged-into ethernet on a new network with DHCP) by looping through all the ip address on the subnet and attempting to login to each as root. If it finds one then try your password. If it doesn't work just hit enter until the loop starts again. If it doesn't find the board then something else is probably wrong.
for ip in $(seq 1 254); do ssh root#xxx.xxx.xxx.$ip -o ConnectTimeout=5; [ $? -eq 0 ] && echo "xxx.xxx.xxx.$ip UP" || : ; done
UPDATE 1
Today I plugged-in the beaglebone and saw Bonjour recognize that it joined the network. So I tried it and it worked. No idea why it decided to all of the sudden but it did. Strange, but true.
I had this issue quite often with Mac OS X 10.7. But unlike Frank Halasz "systemctl status avahi-daemon.service" shown no failure. And in fact the problem was on the Mac side. Restarting Bonjour with the following commands fixed the issue.
$ sudo launchctl unload /System/Library/LaunchDaemons/com.apple.mDNSResponder.plist
$ sudo launchctl load -F /System/Library/LaunchDaemons/com.apple.mDNSResponder.plist

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