Setting tcp connectivity in embedded Linux - tcp

With ARM, Debian 10, as a root, I try to set up static ip, TCP to outer world through Windows (adapter sharing):
ifconfig eth0 down
ifconfig eth0 192.169.200.10 netmask 255.255.255.0 up
ip route flush table main
route add default gw 192.169.200.200 eth0
echo "nameserver 192.169.200.200" > /etc/resolv.conf
It takes me several trials to execute adding-gateway before I can ping outer world by names. Times in the middle route add default gw 192.169.200.200 eth0 returns SIOCADDRT: Network is unreachable. Finally, after repeating it again with pings, ping finally works. What's wrong?

I think you should not have flushed main table which might have wiped the link local entry from the routing table. So instead of following command:
"ip route flush table main"
you could use following:
"route del default"
I hope it helps you understand.

Related

Raspberry pi is unable to reach gateway

Recently we brought raspberry pi 3b.Beginning we used to access the internet using an ethernet cable and it used to connect properly but now raspberry pi is not able to reach the gateway itself and it's taking its default IP address i.e 169.xxx.xxx.xx.
what would be the issue?we tried to reinstalling the operating system again the same issue .it worked for one day after that same problem.so please help me to solve the issue.
Finally, I am able to figure it out after trial and error method. I have missed "auto eth0" before the iface statement i.e
auto eth0
iface eth0 inet static
address xxx.xxx.xxx.xxx
network 255.255.255.0
gateway xxx.xxx.xxx.xxx
dns-nameservers 8.8.8.8
Assuming that you have a windows computer available, open cmd and run the following command:
ipconfig
note down the values that display. Now on your pi, enter the command
sudo nano /etc/network/interfaces
This will open the network interfaces file. Look for the line similar to 'inet eth0 inet manual' Then remove this line and everything to do with the eth0 interface, since we are going to start over.
in the interfaces file, add the following section:
auto eth0
inet eth0 inet static
address xxx.xxx.xxx.xxx
network 255.255.255.0
gateway xxx.xxx.xxx.xxx
dns-nameservers 8.8.8.8
Replace the x in address with the first 3 groups of the value taken from the windows system. For example, if the ip address on the windows system was 192.168.0.221, enter 192.168.0.xxx
The last group of xxx for address should be something unique to everything else on your network.
'gateway' should be whatever the gateway value in windows was (assuming these machines are on the same network)
[Ctrl]+[x], Save changes
reboot via
sudo reboot
once the system has rebooted
ifconfig eth0
should list the new settings. Test them by pinging the below address (google)
sudo ping 8.8.8.8

Configure LXC to use wireless hosted network

I found most of the configuration is for giving static or private network. But I want it to act as a different machine so it will get a separate IP address from the DHCP and I want to do it through nmcli.
Thanks in advance.
If you are using docker as tagged, rather than LXC, use pipework to map the wlan interface from the host to the container
pipework eth2 $CONTAINERID 10.10.9.9/24
or alternatively let the container do the dhcp negotiation for you
pipework eth1 $CONTAINERID dhclient
This setup is based on a macvlan interface so the same concept should work with LXC you just won't get the easy front end.
I'm confused if this is a docker question or an LXC question.
EDIT: as per the comments, wlan interface support in a bridge depends on the wlan vendor. It may work, or it may not work at all.
In any case, you should be able to create a bridge, add your wlan0 interface to the bridge, and then have your LXC container connect to this bridge directly. Then, when you run your DHCP client in the container, it will grab it from the wlan0 interface.
Configure bridge (manually for now)
# ifconfig wlan0 up
# brctl addbr br0
# brctl addif br0 wlan0
# ifconfig br0 up
# dhclient br0
Configure LXC configuration
If using traditional priviliged LXC, edit the container's config file at /var/lib/lxc/$NAME/config,
and update this value to point to your new bridge.
lxc.network.link = br0
Run DHCP in container
# lxc-attach -n $NAME
# dhclient eth0
# ip a
If the output to ip a shows the desired IP, you're all set!
If you want to make the configuration persistent, you'll have to add the bridge to your /etc/network/interfaces file.
IEEE 802.11 doesn’t like multiple MAC addresses on a single client, so bridge and macvlans are not the right solution here.
Use ipvlan in L2 mode.

How to set a specific fixed IP address when I create a docker machine or container?

When I create my container, I want to set a specific container's IP address in the same LAN.
Is that possible? If not, after the creation can I edit the DHCP IP address?
Considering the conclusion of the (now old October 2013) article "How to configure Docker to start containers on a specific IP address range", this doesn't seem to be possible (or at least "done automatically for you by Docker") yet.
Update Nov 2015: a similar problem is discussed in docker/machine issue 1709, which include the recent workaround (Nov 2015)proposed by Tobias Munk (schmunk42) for docker machine
(for container see the next section):
A workaround for some use-cases could be to create machines like so:
192.168.98.100
docker-machine create -d virtualbox --virtualbox-hostonly-cidr "192.168.98.1/24" m98
192.168.97.100
docker-machine create -d virtualbox --virtualbox-hostonly-cidr "192.168.97.1/24" m97
192.168.96.100
docker-machine create -d virtualbox --virtualbox-hostonly-cidr "192.168.96.1/24" m96
If there's no other machine with the same cidr (Classless Inter-Domain Routing), the machine should always get the .100 IP upon start.
Another workaround:
(see my script in "How do I create a docker machine with a specific URL using docker-machine and VirtualBox?")
My virtualbox has dhcp range 192.168.99.100 - 255 and I want to set an IP before 100.
I've found a simple trick to set a static IP: after create a machine I run this command and restart the machine:
echo "ifconfig eth1 192.168.99.50 netmask 255.255.255.0 broadcast 192.168.99.255 up" \
| docker-machine ssh prova-discovery sudo tee /var/lib/boot2docker/bootsync.sh > /dev/null
This command create a file bootsync.sh that is searched by boot2docker startup scripts and executed.
Now during machine boot the command is executed and set static IP.
docker-machine ls
NAME ACTIVE DRIVER STATE URL SWARM
test-1 - virtualbox Running tcp://192.168.99.50:2376 test-1 (mast
Michele Tedeschi (micheletedeschi) adds
I've updated the commands with:
echo "kill `more /var/run/udhcpc.eth1.pid`\nifconfig eth1 192.168.99.50 netmask 255.255.255.0 broadcast 192.168.99.255 up" | docker-machine ssh prova-discovery sudo tee /var/lib/boot2docker/bootsync.sh > /dev/null
then run command (only the first time)
docker-machine regenerate-certs prova-discovery
now the IP will not be changed by the DHCP
(replace prova-discovery by the name of your docker-machine)
April 2015:
The article mentions the possibility to create your own bridge (but that doesn't assign one of those IP addresses to a container though):
create your own bridge, configure it with a fixed address, tell Docker to use it. Done.
If you do it manually, it will look like this (on Ubuntu):
stop docker
ip link add br0 type bridge
ip addr add 172.30.1.1/20 dev br0
ip link set br0 up
docker -d -b br0
To assign a static IP within the range of an existing bridge IP range, you can try "How can I set a static IP address in a Docker container?", using a static script which creates the bridge and a pair of peer interfaces.
Update July 2015:
The idea mention above is also detailed in "How can I set a static IP address in a Docker container?" using:
Building your own bridge
The result should be that the Docker server starts successfully and is now prepared to bind containers to the new bridge.
After pausing to verify the bridge’s configuration, try creating a container — you will see that its IP address is in your new IP address range, which Docker will have auto-detected.
you can use the brctl show command to see Docker add and remove interfaces from the bridge as you start and stop containers, and can run ip addr and ip route inside a container to see that it has been given an address in the bridge’s IP address range and has been told to use the Docker host’s IP address on the bridge as its default gateway to the rest of the Internet.
Start docker with: -b=br0 (that is also what the echo 'DOCKER_OPTS="-b=bridge0"' >> /etc/default/docker can set for you by default)
Use pipework (192.168.1.1 below being the default gateway ip address):
pipework br0 container-name 192.168.1.10/24#192.168.1.1

openstack instance getting ip and not getting ip

I am new to openstack and I followed the installation guide of icehouse for ubuntu 12.04/14.04
I chose 3 node architecture. Controller, Nova, Neutron.
The 3 nodes are installed in VM's. I used nested KVM. Inside VM's kvm is supported so nova will use virt_type=kvm. In controller I created 2 nics. eth0 is a NAT interface with ip 203.0.113.94 and eth1 a host only interface with ip 10.0.0.11.
In nova there are 3 nics. eth0 NAT - 203.0.113.23, eth1 host only 10.0.0.31 and eth2 another host only 10.0.1.31
In neutron 3 nics. eth0 NAT 203.0.113.234, eth1 host only 10.0.0.21 and eth2 another hosty only 10.0.1.21 (during installation guide in neutron node i created a br-ex (and a port to eth0) which took the settings of eth0 and eth0 settings are:
auto eth0 iface eth0 inet manual up ifconfig $IFACE 0.0.0.0 up
up ip link set $IFACE promisc on
down ip link set $IFACE promisc off
down ifconfig $IFACE down)
Everything seemed fine. I can create networks, routers etc, boot instances but I have this error.
When I launch an instance it takes a fixed ip but when I log in into instance (cirros) can't ping anything. ifconfig with no ip.
I noticed that in demo-net (tenant network) properties under subnet in the ports field it has 3 ports. 172.16.1.1 network:router_interface active 172.16.1.3 network:dhcp active 172.16.1.6 compute:nova down
I searched for solutions over the net but couldn't find anything!
Any help?
Ask me if you want specific logs because I don't know which ones to post!
Thanks anyway!
Looks like you are using Fixed IP to ping..If so please assign floating IP to your instance, and then try to ping..
If you have already assigned floating IP and you are pinging using that IP..please upload log of your instance

Multiple IPs + bridge for KVM

I got a problem at the moment and really don't know where the mistake is. I got a Root-Server from my ISP. This Root-Server has already one IP included and today i booked two more IP-Addresses. So what I want to do now is to map this two new IP-Adresses to two virtual Machines but also hold the included IP for the Root-Server. So how I realize this?
I thought something like:
br0 - holds the original IP of the Root-Server
br0:0 - holds first IP of first virtual Machine
br0:1 - holds second IP of second virtual Machine
But this doesn't work. Any Ideas. I'm really frustrated. Worked the hole Day on it and no solution.
I was also struggling with similar scenario, I've got server and got to point that setting up bridge did cut me out and had to restart to be able to reach it , anyway I've managed to handle it by iptables ..
#create alias for your second ip address (lets say its 111.222.333.2 , local address 192.168.1.2)
ifconfig eth0:1 111.222.333.2
#you should add netmask to be proper if you've got subnet
#now you should be able to ping this second address from outside world - try it,
#that is if you have not set up firewall to block pings ... flush iptables rules if you are not sure...
#set up NAT rule (network-address-translate : outside ip-> local ip and back local ip->outside ip)
#assumes your virtual machines lives as 192.168.1.2
iptables -t nat -A PREROUTING -d 111.222.333.2 -j DNAT --to-destination 192.168.1.2
iptables -t nat -A POSTROUTING -s 192.168.1.2 -j SNAT --to-source 111.222.333.2
This did help me with server which has multiple IP addresses and KVM virtual machines,
which were originally run in default network (forward mode=nat), so they had internet through NAT and internal IP at first , this also gives them outside-world public IP address.
You can also do these redirects on port-by-port basis by adjusting iptables rule to set address like -d 111.222.333.2:80 -p tcp and also adding port to local address ...
You may also need to turn on device IP forwarding, you can check that by for example sysctl -a | grep forward (where you should see it on for your eth0 device) , optionally adjusting it by proper sysctl command like
sysctl -w net.ipv4.ip_forward=1
Map br0 to VM1 and VM2 as TAP DEVICE and in VM1 and VM2 you can see that as eth device;
Assign IP1 and IP2 to VM1 and VM2 respectively; With this configuration you can ping from VM1 to VM2 and from host machine to any guest machine(VM1 or VM2);
The following link will help you setting up TAP device for VM via bridge; See qemu-ifup script specified there and understand it well.

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