I am trying to use a single IP as a "floating IP" by assigning it to a secondary interface eth1 between 2 VMs. The primary interface eth0 has 2 different IPs for both VMs. Only one of the VMs will have the IP assigned to eth1 at any given time. If we have any issues with the primary VM we will unassign the IP from eth1 of the primary VM and reassign it to the secondary VM.
We are unassigning and assigning the IP using -
/sbin/ip addr ${ACTION} ${IP} dev ${INTERFACE}
However once we unassign the IP from eth1 of the primary VM and assign it to eth1 of the secondary VM I am unable to ssh to the secondary VM right away. I get a -
ssh: connect to host x.x.x.x port 22: Connection timed out
After about 15 mins some cache somewhere gets cleared and then I am able to ssh to the secondary box.
Have the following setting already updated in sshd_config and sshd has been restarted.
GSSAPIAuthentication no
UseDNS no
We are using Redhat 7.6
Any help in the troubleshooting what could be causing the delay in ssh'ing to the secondary box is much appreciated!
Thanks!
Your issue is with your network gear and the clients arp tables.
After you change the address check your arp tables with arp -a on Linux and show ip arp (Cisco gear). You will see the old MAC address maps to the old server IP.
After you change ip addresses send a gratuitous arp and that will force everything to update.
Assume your ethernet address is 10.0.10.1 and you are using eth1.
yum install arping -y
arping -A -I eth1 10.0.10.1
This very similar to what VMware does when you VMotion a VM to another host. It sends an RARP to notify the network the MAC address has moved to different a port.
EDIT: Also note, in older RHEL ver ifup-eth script used the arping tool to send a GARP. That means I might also try ip link set eth1 down and ip link set eth1 up see if that works.
This issue got resolved. We had to update the arp neihbor cache to get this to work so incorporated that into our script.
I am using Vmware Player to use Ubuntu 14.04 but I am unable to get any internet connection in my virtual machine even though my system is connected to the internet. The original OS in my system is Windows 7. Can anybody suggest the way out.
Found the solution by browsing through multiple threads. Compiling it here.
EDIT : Please check if your network is in bridged mode or not if you are using VMWare/ VirtualBox before following the steps below. Enabling bridge mode and restarting guest OS can resolve the issue.
First check if your network is disabled by using the following cmd in terminal:
sudo lshw -C network
If it shows disabled after the name of your adapter ( note down the logical name for later use)
*-network DISABLED
description: Ethernet interface
product: 82545EM Gigabit Ethernet Controller (Copper)
vendor: Intel Corporation
physical id: 1
bus info: pci#0000:02:01.0
logical name: ens33
All we need to do is enable the adapter, so lets get started.
open up your interfaces file by using the following cmd:
sudo gedit /etc/network/interfaces
My file had the following data written:
auto lo
iface lo loopback
But the logical name of my NIC was ens33 ( not lo), so i changed it to read the following and saved the file.
auto lo
iface lo inet loopback
auto eth0
iface eth0 inet dhcp
auto wlan0
iface wlan0 inet dhcp
Now time to restart the networking service.
sudo /etc/init.d/networking restart
check if network is back up, it shouldn't have that disabled tag anymore.
sudo lshw -C network
Enjoy your internet :)
If that doesn't work -> But as explained earlier change the network adaptor settings to bridged in your virtual machine settings.
If all that does not work, the best way to resolve the issue is
Restore your VM network settings
If you are using an older version download a new version (trial version would also work) - we are just updating your settings
Follow the steps:
Depending on how you are connected to the network, try either Bridged or NAT mode for the VM's network adapter. Keep in mind that you may lose connectivity from the host machine to the VM. In this case you'll need another network adapter.
In most cases NAT should work. In this case only your host machine's IP is visible to the network, and ports are allocated for the VM to communicate to the outside world. The problem is that you can't connect to the VM from the host machine if you need to. Add another adapter as I mentioned above and connect to its IP address. You will have two adapters - one for the Internet and the other for host-to-guest.
In the bridge mode the VM is visible to the outside network, so a network configuration is required that enables the VM to get an IP address and participate in the network (for example, network administrators may block unknown MAC addresses). The host machine talks with the VM as it were just a computer on the network.
Update your question with additional information if my suggestion does not work: guest OS, how your host computer is connected to the network, what the current configuration of the VM's network adapters is. Is it a home or a workplace computer?
UPDATE
So I guess if you are connected to a corporate LAN, then NAT will work while Bridge will not. To add another interface 1) add an adapter in VMWare Player; 2) Add an interface in Ubuntu. Assuming your existing interface is eth0, edit /etc/network/interfaces, adding these lines:
auto eth1
iface eth1 inet dhcp
Then restart the networking service:
sudo /etc/init.d/networking restart
UPDATE 2
Another reason for your not being able to connect to the Internet may be a proxy server. Make sure that the proxy configuration in the VM is the same as in the host machine.
CLose VM,
Go to VM Settings and Network adapters
Then click on adapter 1 and select Shared Networking NAT.
Start VM
I have installed NetBSD 4.0.1 x68k on XM6i (http://www.ceres.dti.ne.jp/tsutsui/netbsd/x68k/NetBSD-x68k-on-XM6i.html) as a virtual machine emulating a 68030 platform. I have gotten everything to work except networking.
According to the documentation, you need to install a TAP-Win32 network adapter from OpenVPN installer, which I have. I have set the ipv4 settings of this adapter to IP address: 192.168.2.1 and Netmask: 255.255.255.0
In NetBSD, I have created a /etc/ifconfig.ne0 file to configure the ne0 network interface, which I assume represents the TAP-Win32 adapter. This file sets IP address to 192.168.2.17 and Netmask to 255.255.255.0
When i use "ping 192.168.2.1" on NetBSD I am unable to ping the host, the error message being: "host is down"
Does anyone know whats going wrong? If anyone could give me any advice I would be most grateful.
Update: Above problem has been solved .... but not quite.
If I have tinkered around with settings on host, now I can ping guest only if I run tcpdump -i ne0 on guest. Then after that I can also ping the host from the guest. I have tried restarting and trying without tcpdump but the changes didnt seem to stick, so i have to run tcpdump in order to setup the host only connection.
Is there any way I can do this without tcpdump and make the fix stick?
Edit: Here is the link to the new question with a more detailed explanation of the problem: Host Only connection NetBSD to Windows
It turns out to run a complete networking emulation on a 68030 machine on the latest version of XM6i, you need to run tcpdump on boot. There is no way around it.
First of all this question is not about virtual host in Apache.
I have a network with the following address: 1.1.1.0
I have several host on this network: 1.1.1.1, 1.1.1.2, 1.1.1.3 and 1.1.1.4
The first host send a broadcast UDP paquet answer and expect other host to answer him.
Is it possible for my dev machine (1.1.1.4) to emulate the following virtual host : 1.1.1.5, 1.1.1.6, etc. ?
I'm using QUdpSocket from Qt 5.2.1 on MacOS 10.9 but I am open to any other tech that would help me do the trick.
It depends on you OS.
On linux, you can create multiple virtual network devices, and bind each of those devices to a different network address. The virtual network devices have the name of a real device with a :xxx numeric suffix. For example, if your primary network device is eth0, you can run the command
ifconfig eth0:1 1.1.1.5
to create the virtual device eth0:1 and bind it to the address 1.1.1.5. This is only temporary (it will go away when you reboot); if you want it to come back when you reboot, you can edit the `/etc/network/interfaces file to look something like:
auto eth0
iface eth0 inet static
address 1.1.1.4
netmask 255.255.255.0
gateway 1.1.1.1
auto eth0:1
address 1.1.1.5
netmask 255.255.255.0
the lack of a gateway in the eth0:1 part means that it won't use this interface for routing, so it just exists for receiving packets and explicit binding to an ip address.
Install VirtualBox (here) and make a tiny disk image big enough for a small Linux distro. Run several copies, each one at a different IP address and run a tiny netcat script in each one that listens and sends replies.
#!/bin/bash
while :
do
command=$(nc -ul 1234)
process $command and reply
done
Or, read this and go with Chris's idea which is lighter weight on resources!
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I'm working on a balloon project with a Raspberry Pi. When we potentially recover the Raspberry Pi, it will most likely be in a rural location and I'd like to turn off the Pi at that point safely.
Without a router or network nearby, I was wondering if there is a way to hook up a Raspberry Pi with an Ethernet cable directly to a laptop?
It's a solution for Ubuntu (the idea also works for Windows or Mac) I just tried today and it works like a charm.
Material
a cross-over Ethernet cable (the name is fancy but it's just a normal Ethernet cable)
a laptop (ubuntu)
a Raspberry Pi (I have the Pi2)
Prerequisites on your ubuntu
Install network-manager
$sudo apt-get install network-manager
Install nmap
$sudo apt-get install nmap
Edit Wired connection on your laptop (Ubuntu)
Change IpV4 settings to "Share to other computers"
Save the setting
Reboot your laptop
Share WiFi connection of your laptop via Ethernet crossover cable
Hook up your RPi with your laptop using the Ethernet cable
Look up the broadcast address of the Ethernet connection (Laptop),
$/sbin/ifconfig eth1 | grep "Bcast" | awk -F: '{print $3}' | awk '{print $1}' 10.42.0.255
Use this address to find out the IP address of your RPi, it's 10.42.0.96 in my case because 10.42.0.1 is my laptop
$nmap -n -sP 10.42.0.255/24
Starting Nmap 6.40 ( http://nmap.org ) at 2016-02-20 23:07 CET
Nmap scan report for 10.42.0.1
Host is up (0.00031s latency).
Nmap scan report for 10.42.0.96
Host is up (0.0023s latency).
Nmap done: 256 IP addresses (2 hosts up) scanned in 2.71 seconds
Login to your RPi from your laptop (-Y with X-forwarding)
$ssh -Y pi#10.42.0.96
Lo and behold! Now your RPi is connected to your laptop and RPi can share the WiFi connection.
pi#raspberrypi ~ $
Share display & keyboard of your laptop with RPi
Install vncserver on Raspberry Pi
$ sudo apt-get update
$ sudo apt-get install tightvncserver
Install vncviewer on your laptop by downloading RealVNC (it supports multiple platforms)
http://www.realvnc.com/download/vnc/
To be able to copy & paste from VNC server <--> VNC viewer, you need to install autocutsel on your RPi.
$sudo apt-get install autocutsel
If this site doesn't work, try to download the .deb directly from a mirror site, e.g.
mirror.hmc.edu/debian/pool/main/a/autocutsel/autocutsel_0.10.0-1_armhf.deb
and install it
$sudo dpkg -i autocutsel_0.10.0-1_armhf.deb
Start vncserver on your RPi (You have to restart vncserver after installing autocutsel, you can issue $vncserver -kill :1)
$vncserver :1
Add autocutsel -fork to /home/pi/.vnc/xstartup
#!/bin/sh
xrdb $HOME/.Xresources xsetroot -solid grey
autocutsel -fork
#x-terminal-emulator -geometry 80x24+10+10 -ls -title "$VNCDESKTOP Desktop" &
#x-window-manager &
# Fix to make GNOME work
export XKL_XMODMAP_DISABLE=1
/etc/X11/Xsession
Start vncviewer on your laptop
$vncviewer
A vncviewer window will pop up and type in the IP address of your RPi (given by your laptop) followed by port 1, which is your VNC server. for example: 10.42.0.96:1 in my case.
Connect it to the vncserver hosted on your RPi by typing in a password (set up a password yourself)
12.Now you can see the desktop of RPi on your laptop, and I opened my browser to show the shared WiFi connection is working as well.
See Raspberry Pi desktop on your ubuntu
No router + no screen + regular Ethernet cable + RPI 2 + Raspbian Lite 2018-11-13 + Ubuntu 18.10
First we must enable the SSH server on the Pi, which is disabled by default for security.
If you already have a shell on the Pi through a non-SSH method such as screen + keyboard or UART (see below), just run:
sudo systemctl enable ssh
sudo service sshd start
as explained at: https://raspberrypi.stackexchange.com/questions/58478/ssh-not-working-with-fresh-install This persists across boots.
Otherwise, insert he SD card on your host, and create a magic empty file named ssh file in the boot/ partition.
On Ubuntu hosts, it gets mounted automatically and you can do just:
sudo touch /media/$USER/boot/ssh
which you can confirm with:
lsblk
which contains:
mmcblk0 179:0 0 14.4G 0 disk
├─mmcblk0p1 179:1 0 43.9M 0 part /media/ciro/boot
└─mmcblk0p2 179:2 0 14.4G 0 part /media/ciro/rootfs
If you don't enable the SSHD daemon on the Pi then SSH connection will fail with:
ssh: connect to host 10.42.0.160 port 22: Connection refused
when we try it later on.
After enabling the SSH server
Next, boot the Pi, and link an Ethernet cable from your laptop directly to the Pi:
On Ubuntu 17.04 to work around this bug as mentioned on this answer you first need:
sudo apt-get install dnsmasq-base
On the host, open the network manager:
nm-connection-editor
And go:
+ sign (Add a new connection)
Ethernet
Create
IPv4 Settings
Method: Shared to other computers
Set a good name for it
Save
Find the IP of the Pi on host:
cat /var/lib/misc/dnsmasq.leases
outputs something like:
1532204957 b8:27:eb:0c:1f:69 10.42.0.160 raspberrypi 01:b8:27:eb:0c:1f:69
10.42.0.160 is the IP, then as usual:
ssh pi#10.42.0.160
I also have the following in my .bashrc:
piip() ( cat /var/lib/misc/dnsmasq.leases | cut -d ' ' -f 3; )
pissh() ( sshpass -p raspberry ssh "pi#$(piip)"; )
From inside the Pi, notice that it can access the internet normally through your host's other interfaces:
ping google.com
For example on my laptop, the Pi takes up the Ethernet, but the host is also connected to the internet through WiFi.
The crossover cable is not required if the host network card supports Auto MDI-X. This is the case for most recent hardware, including for example the 2012 Lenovo T430 I tested with, which has an "Intel® 82579LM Gigabit Network Connection" which documents support for Auto MDI-X.
Now you can also:
access the Internet from the PI through your Ubuntu's Wifi connection
open a VNC to get rid of the display as well: https://raspberrypi.stackexchange.com/questions/14611/how-to-set-up-raspberry-pi-without-a-monitor/54393#54393
UART serial USB converter
This is an alternative to SSH if you just want to get a shell on the Pi: https://en.wikipedia.org/wiki/Serial_port
This does not use SSH or networking itself, but rather the older, simpler, more direct, more reliable, lower bandwidth, lower distance serial interface. The Pi won't have access to the Internet with this method.
Desktop computers still have a serial port which you can connect directly wire to wire with the Pi, but these are hidden in most laptops, and so we need to buy a cheap USB adapter. Here I've used a "DSD TECH USB to TTL Serial Converter" https://www.amazon.co.uk/gp/product/B072K3Z3TL See also: https://unix.stackexchange.com/questions/307390/what-is-the-difference-between-ttys0-ttyusb0-and-ttyama0-in-linux/367882#367882
First plug the SD card on the host, and edit the config.txt file present in the first partition to add:
enable_uart=1
as explained at: https://www.raspberrypi.org/forums/viewtopic.php?f=28&t=141195
This first partition contains the bootloader, its configuration files and the (Linux / your) kernel, config.txt being one of them. The second partition contains the actual Linux root filesystem.
Now connect your computer to the Pi as:
You only need to attach 3 cables:
Ground to Ground
Tx on Pi to Rx on the USB to serial port
Rx on Pi to Tx on tye USB to serial port
This is also documented at: https://www.raspberrypi.org/documentation/usage/gpio/README.md
Be careful not to link the Ground to the 5V, I've already burned 2 UART to USB chips and a RPI UART by doing that!
You don't need to connect the 5V to the 5V at all. I think you can power your Pi like that, but I've read that this is a bad idea, just use the usual USB power source.
Finally, plug the USB side of the connector to your host computer, and get a shell with:
sudo apt install screen
sudo usermod -a -G dialout $USER
screen /dev/ttyUSB0 115200
Exit with Ctrl-A \.
Here is a video by Adafruit showing it: https://www.youtube.com/watch?v=zUBPeoLW16Q
See also
Similar question on RPI SE: https://raspberrypi.stackexchange.com/questions/3867/ssh-to-rpi-without-a-network-connection
You don't need a cross-over cable. You can use a normal network cable since the Raspberry Pi LAN chip is smart enough to reconfigure itself for direct network connections.
Cheers
I've just implemented and test this successfully. Same situation with my project, want to connect to a Raspberry Pi with no router or wifi. Just a simple ethernet cable.
Using ssh putty program put the address as
raspberrypi.local
Log and in and you can access the terminal.
Alternatively if VNC server is setup, use VNC server and put
raspberrypi.local:1
In the server address. input your VNC server password and you've now got GUI access to do what you want.
In may case it was run scripts in a remote location. In the posters situation, safely shutdown the Pi. Simples Pimples.
Configure static ip for your laptop and raspberry pi.
On the rapberryPI configure it as following.
pi#rpi>sudo nano /etc/network/interfaces
Then configure following as required to connect to your laptop.
iface eth0 inet static
address 192.168.1.81
netmask 255.255.255.0
broadcast 192.168.1.255
configure static ip on the raspberry pi:
sudo nano /etc/network/interfaces
and then add:
iface eth0 inet static
address 169.254.0.2
netmask 255.255.255.0
broadcast 169.254.0.255
then you can acces your raspberry via ssh
ssh pi#169.254.0.2
Here are the instructions for Windows users on connecting to a RPi by using just an Ethernet cable and a DHCP server. There is no need for a cross over cable, as the RPi can handle it. I have a blog post that documents this with pictures here which may be easier to follow.
Downloads
Download the DHCP Server for Windows (download link is here). Unzip the zip file and open the dhcpwiz application, which will configure the DHCP server.
DHCP Server Configuration
Hit next on the first screen.
On the second screen, look for a "Local Area Connection" row and verify its IP address is 0.0.0.0 and its status is enabled. Connect the Ethernet cable from the RPi to your laptop, and turn on the Pi. Hit refresh on this screen until the IP address changes to 169.254.*.*. If it is anything else then you should alter your network settings for the Local Area Connection (make sure it is not a static IP/DNS). Click on this Local Area Connection row and hit next.
Check HTTP (Web Server). This makes it much more easy to locate the RPi's IP address. Hit Next.
Take the defaults and hit Next until you get to the Writing the INI file screen. Check Overwrite existing file and hit the Write INI file button. Then hit Next.
On the final screen, check Run DHCP server immediately and hit `Finish.
DHCP Server and Obtaining the IP Address of your Raspberry PI
This launches the actual DHCP server, using the configuration you just created in the previous wizard. Click the Continue as tray app button, and the DHCP server will be minimized to your system tray.
Anywhere from 1 second to 5 minutes from now you will see an alert on the system tray with your laptop and your RPi's new IP address. This alert is really quick and you will probably miss it. Normally your RPi's IP is 169.254.0.2, but it could be *.01 or even something else. It is easier to access the DHCP server's web UI at http://localhost/dhcpstatus.xml. This will list the hostname as "raspberrypi" with its IP address.
Now you can putty or remote desktop into your RPi, and configure its wireless settings or whatever you want to do.
Trouble shooting
This can be somewhat finicky. I've had my connection appear to drop and have been unable to SSH back in using the IP address. Normally, I can restart the Pi and get the IP address again. Sometimes I have to restart both the RPi and the DHCP server. Sometimes I have to do this multiple times. At one point when I wasn't getting a connection for 15 minutes, I copied all of the files in the dhcpsrv2.5.1 folder to a new folder and tried again; it immediately worked.
You could use a cross-over ethernet cable - http://en.wikipedia.org/wiki/Ethernet_crossover_cable
Assuming your RPi is a DCHP Client, then best to run a simple DHCP server on your notebook to assign the RPi an IP address.
Yes, you can connect the raspberry direct to your PC without router.
For this is necessary that the raspberry and your computer are on the same subnet, and they both have a static ip configured (And an Ethernet cable connected between the two devices).
An ideal configuration would be the following:
Raspberry on eth0: IP: 192.168.1.10 SubNet: 255.255.255.0
Your PC: IP: 192.168.1.11 SubNet 255.255.255.0
To set a manual IP on raspberry you can follow this guide
In your PC you can set a manual IP in the network adapter settings,and the procedure depends on your operating system.
When you have configured the two static IP, you can connect to the raspberry via SSH using the IP set (192.168.1.10).
Another simpler method is to attach on GPIO a button to turn off the raspberry! Take a look here!
What worked for me was a combination of the answers from Nicole Finnie and Ciro Santilli along with some answers from elsewhere.
Setting up the pi
We will need to do two things: activate ssh on the pi, and configure the pi to use a static ip.
Activating ssh
Add a file called ssh in the boot partition of the sd card (not the /boot folder in the root partition). This is well documented other places.
Static ip
Open /etc/dhcpcd.conf on the pi's SD-card, and uncomment the example for a static ip (starts around line 40). Set the addresses to
# Example static IP configuration:
interface eth0
static ip_address=10.42.0.182/24
static routers=10.42.0.1
static domain_name_servers=10.42.0.1 8.8.8.8 fd51:42f8:caae:d92e::1
Setting up your laptop
First, make sure you have networkmanager (with GUI) installed on your laptop. Then, make sure dnsmasq is not running as a service:
systemctl status dnsmasq
If this command prints that the service is stopped, then you're good.
Next we have to config networkmanager. Open /etc/NetworkManager/NetworkManager.conf and add the following two lines at the top:
[main]
DNS=dnsmasq
Then reboot. This step might not be necessary. It might be sufficient to restart the NetworkManager service. Now go to the NetworkManager GUI (usually accessed by an icon in the corner of the screen) and choose Edit Connections... In the window that pops up, click the + icon to create a new connection. Choose Ethernet as the type and press Create.... Go to the IPv4 Settings tab and select the method Shared to other computers. Give the connection a good name and save.
Connect the Raspberry Pi and make sure your laptop is using your new connection as its ethernet connection. If it is, your pi should now have an ip given to it by your pc. You can find this by first running ifconfig. This should give you several blocks of text, one for each network interface. You're interested in the one that is something like enp0s25 or eth0. It should have a line that reads something similar to
inet 10.42.0.1 netmask 255.255.255.0 broadcast 10.42.0.255
look at the broadcast address (in this case 10.42.0.255). If it is different than mine, power off the pi and put the SD card back in your laptop to change the static ip_address to something where the first three numbers are the same as in your broadcast address. Also change the static routers and the first of the domain_name_servers to your laptop's inet address. Power the pi back on and connect it. Run ifconfig again to see that the addresses have not changed.
ssh into the pi
ssh pi#10.42.0.182
If you get connection refused, the pi isn't running an ssh server. If you get host unreachable, I'm sorry.
Hope this helps someone!