Mininet+ GNS3: pingall fails + dhcp doesn't work - networking

I'm still a beginner, I'm facing some issues and I need your help.
1
I integrated mininet to gns3 successfully, the mininet VM can ping all the routers and other VMs, Also it can get an address through dhcp immediately without problems. However, when I run this command,
sudo mn --controller=remote,ip=192.168.1.10, port=6653
the ovswitch connects to the floodlight controller but pingall fails.
2
I tried to add my network interface (eth0) to the my bridge (s1) in order to connect the mininet host to the internet, the dhclient takes long time and can't assign an IP address to the bridge.
add eth0: ovs-vsctl add-port s1 eth0
remove eth0's IP addressing: ifconfig eth0 0
make s1 interface get a DHCP IP: dhclient s1
Im using:
floodlight master
ovs_version 2.5.4
GNS3 version 2.1.8 on Windows (64-bit) with Python 3.6.5 Qt 5.8.0 and PyQt 5.8.
ubuntu 16.04.4
Please can someone help me to solve these issues.
Thanks in advance.

Related

Why is it not possible to ping a real machine to a vm inside openstack

I created a vm (vm-devstack-01) using Vagrant and Virtualbox in which I installed Devstack. The vm has an enp0s3 interface in NAT mode and an enp0s8 interface in bridge mode. The real network I use in my house is 192.168.88.0/24. This network uses DHCP addressing.
vm-devstack-01:
I set FLOATING_RANGE from local.conf to 192.168.88.224/27.
My local.conf:
[[local|localrc]]
ADMIN_PASSWORD=admin
DATABASE_PASSWORD=$ADMIN_PASSWORD
RABBIT_PASSWORD=$ADMIN_PASSWORD
SERVICE_PASSWORD=$ADMIN_PASSWORD
HOST_IP=192.168.88.43
FLAT_INTERFACE=enp0s8
FLOATING_RANGE=192.168.88.224/27
FIXED_RANGE=10.11.12.0/24
FIXED_NETWORK_SIZE=256
Later I created a debian VM (vm-debian-01) on openstack which received floating ip 192.168.88.230.
Also, the security group releasing the ping was created:
Ingress IPv4 ICMP Any 0.0.0.0/0
With this configuration it was possible to ping vm-devstack-01 to vm-debian-01 created inside openstack.
But I can't ping from the real machine (my notebook - IP 192.168.88.28) to vm-debian-01. What am I doing wrong ?
You need MASQUERADE definitions on your Openstack host machine.
That is, network translation for packets to-from your VM.
At the same time, you need routing to your Openstack host from all other networks that you want to reach VM's.
Masquerade rules
Routing
Proper Security Group settings in Openstack

Setting network device priority with nmcli in Fedora

I am on Fedora v33 Server edition (no GUI) and I have setup 2 network connections.
One is Ethernet, which I use to connect my Macbook to the Linux machine, the other is the WLAN connection the machine uses to connect to the internet.
So now whenever I do
nmcli con up eno1
I lose access to the Internet (ping www.google.com does not return any packets)
When the ethernet is down everything works, but I cannot use ethernet obviously.
Something similar can happen on a Mac OS where I can simply "drag" a network to set the priority. How do I do the same using only the terminal on a unix system like Fedora?
Ok after some research I ran into this great tool called nmtui
sudo dnf install NetworkManager-tui
And after installing the tool and running it with sudo nmtui I edited my ethernet connection and saw the option called
Never use this network for default route which translates to the option never-default=true inside the [ipv4] in the /etc/NetworkManager/system-connections/ config file.
After that I ran sudo nmcli con down eno1 && sudo nmcli con up eno1 and after running nmcli again I can see that the order of connections charged, where now my WLAN is first and my ethernet connection is second.

Failed to ssh to machine after installing Docker

My ssh stops working after I successfully installed Docker (following the official site instruction https://docs.docker.com/engine/installation/) on an ubuntu machine A. Now my laptop cannot ssh to A but ok for other machines, say B, that sitting in the same network environment as A. A can ssh to B and B can also ssh to A. What could be the problem? Can anyone suggest how I can make a diagnostic?
If you are using a vpn service you might be encountering an ip conflict between docker0 interface and your vpn service.
to resolve this:
stop docker service:
sudo service docker stop
remove old docker0 interface created by docker
ip link del docker0
configure docker0 bridge (in my case i only had to define "bip" option)
start the docker service:
sudo service docker start
Most probably there is ip conflict between docker0 interface and your VPN service. As already answered, way is to stop docker service, remove docker0 interface and configure daemon.json file. I added following lines to my daemon.json
{
"default-address-pools":
[
{"base":"10.10.0.0/16","size":24}
]
}
My VPN was providing me an IP like 192.168.. so I chose a base IP that does not fall in that range. Note that the daemon.json file does not exist, so you have to create it in, etc/docker/.

Docker 1.10 container's IP in LAN

Since Docker 1.10 (and libnetwork update) we can manually give an IP to a container inside a user-defined network, and that's cool!
I want to give a container an IP address in my LAN (like we can do with Virtual Machines in "bridge" mode). My LAN is 192.168.1.0/24, all my computers have IP addresses inside it. And I want my containers having IPs in this range, in order to reach them from anywhere in my LAN (without NAT/PAT/etc...).
I obviously read Jessie Frazelle's blog post and a lot of others post here and everywhere like :
How to set a docker container's iP?
How to assign specific IP to container and make that accessible outside of VM host?
and so much more, but nothing came out; my containers still have IP addresses "inside" my docker host, and are not reachable for others computers on my LAN.
Reading Jessie Frazelle's blog post, I thought (since she uses public IP) we can do what I want to do?
Edit: Indeed, if I do something like :
network create --subnet 192.168.1.0/24 --gateway 192.168.1.1 homenet
docker run --rm -it --net homenet --ip 192.168.1.100 nginx
The new interface on the docker host (br-[a-z0-9]+) take the '--gateway' IP, which is my router IP. And the same IP on two computers on the network... BOOM
Thanks in advance.
EDIT : This solution is now useless. Since version 1.12, Docker provides two network drivers : macvlan and ipvlan. They allow assigning static IP from the LAN network. See the answer below.
After looking for people who have the same problem, we went to a workaround :
Sum up :
(V)LAN is 192.168.1.0/24
Default Gateway (= router) is 192.168.1.1
Multiple Docker Hosts
Note : We have two NIC : eth0 and eth1 (which is dedicated to Docker)
What do we want :
We want to have containers with ip in the 192.168.1.0/24 network (like computers) without any NAT/PAT/translation/port-forwarding/etc...
Problem
When doing this :
network create --subnet 192.168.1.0/24 --gateway 192.168.1.1 homenet
we are able to give containers the IP we want to, but the bridge created by docker (br-[a-z0-9]+) will have the IP 192.168.1.1, which is our router.
Solution
1. Setup the Docker Network
Use the DefaultGatewayIPv4 parameter :
docker network create --subnet 192.168.1.0/24 --aux-address "DefaultGatewayIPv4=192.168.1.1" homenet
By default, Docker will give to the bridge interface (br-[a-z0-9]+) the first IP, which might be already taken by another machine. The solution is to use the --gateway parameter to tell docker to assign a arbitrary IP (which is available) :
docker network create --subnet 192.168.1.0/24 --aux-address "DefaultGatewayIPv4=192.168.1.1" --gateway=192.168.1.200 homenet
We can specify the bridge name by adding -o com.docker.network.bridge.name=br-home-net to the previous command.
2. Bridge the bridge !
Now we have a bridge (br-[a-z0-9]+) created by Docker. We need to bridge it to a physical interface (in my case I have to NIC, so I'm using eth1 for that):
brctl addif br-home-net eth1
3. Delete the bridge IP
We can now delete the IP address from the bridge, since we don't need one :
ip a del 192.168.1.200/24 dev br-home-net
The IP 192.168.1.200 can be used as bridge on multiple docker host, since we don't use it, and we remove it.
Docker now supports Macvlan and IPvlan network drivers. The Docker documentation for both network drivers can be found here.
With both drivers you can implement your desired scenario (configure a container to behave like a virtual machine in bridge mode):
Macvlan: Allows a single physical network interface (master device) to have an arbitrary number of slave devices, each with it's own MAC adresses.
Requires Linux kernel v3.9–3.19 or 4.0+.
IPvlan: Allows you to create an arbitrary number of slave devices for your master device which all share the same MAC address.
Requires Linux kernel v4.2+ (support for earlier kernels exists but is buggy).
See the kernel.org IPVLAN Driver HOWTO for further information.
Container connectivity is achieved by putting one of the slave devices into the network namespace of the container to be configured. The master devices remains on the host operating system (default namespace).
As a rule of thumb you should use the IPvlan driver if the Linux host that is connected to the external switch / router has a policy configured that allows only one MAC per port. That's often the case in VMWare ESXi environments!
Another important thing to remember (Macvlan and IPvlan): Traffic to and from the master device cannot be sent to and from slave devices. If you need to enable master to slave communication see section "Communication with the host (default-ns)" in the "IPVLAN – The beginning" paper published by one of the IPvlan authors (Mahesh Bandewar).
Use the official Docker driver:
As of Docker v1.12.0-rc2, the new MACVLAN driver is now available in an official Docker release:
MacVlan driver is out of experimental #23524
These new drivers have been well documented by the author(s), with usage examples.
End of the day it should provide similar functionality, be easier to setup, and with fewer bugs / other quirks.
Seeing Containers on the Docker host:
Only caveat with the new official macvlan driver is that the docker host machine cannot see / communicate with its own containers. Which might be desirable or not, depending on your specific situation.
This issue can be worked-around if you have more than 1 NIC on your docker host machine. And both NICs are connected to your LAN. Then can either A) dedicate 1 of your docker hosts's 2 nics to be for docker exclusively. And be using the remaining nic for the host to access the LAN.
Or B) by adding specific routes to only those containers you need to access via the 2nd NIC. For example:
sudo route add -host $container_ip gw $lan_router_ip $if_device_nic2
Method A) is useful if you want to access all your containers from the docker host and you have multiple hardwired links.
Wheras method B) is useful if you only require access to a few specific containers from the docker host. Or if your 2nd NIC is a wifi card and would be much slower for handling all of your LAN traffic. For example on a laptop computer.
Installation:
If cannot see the pre-release -rc2 candidate on ubuntu 16.04, temporarily add or modify this line to your /etc/apt/sources.list to say:
deb https://apt.dockerproject.org/repo ubuntu-xenial testing
instead of main (which is stable releases).
I no longer recommended this solution. So it's been removed. It was using bridge driver and brctrl
.
There is a better and official driver now. See other answer on this page: https://stackoverflow.com/a/36470828/287510
Here is an example of using macvlan. It starts a web server at http://10.0.2.1/.
These commands and Docker Compose file work on QNAP and QNAP's Container Station. Notice that QNAP's network interface is qvs0.
Commands:
The blog post "Using Docker macvlan networks"[1][2] by Lars Kellogg-Stedman explains what the commands mean.
docker network create -d macvlan -o parent=qvs0 --subnet 10.0.0.0/8 --gateway 10.0.0.1 --ip-range 10.0.2.0/24 --aux-address "host=10.0.2.254" macvlan0
ip link del macvlan0-shim link qvs0 type macvlan mode bridge
ip link add macvlan0-shim link qvs0 type macvlan mode bridge
ip addr add 10.0.2.254/32 dev macvlan0-shim
ip link set macvlan0-shim up
ip route add 10.0.2.0/24 dev macvlan0-shim
docker run --network="macvlan0" --ip=10.0.2.1 -p 80:80 nginx
Docker Compose
Use version 2 because version 3 does not support the other network configs, such as gateway, ip_range, and aux_address.
version: "2.3"
services:
HTTPd:
image: nginx:latest
ports:
- "80:80/tcp"
- "80:80/udp"
networks:
macvlan0:
ipv4_address: "10.0.2.1"
networks:
macvlan0:
driver: macvlan
driver_opts:
parent: qvs0
ipam:
config:
- subnet: "10.0.0.0/8"
gateway: "10.0.0.1"
ip_range: "10.0.2.0/24"
aux_address: "host=10.0.2.254"
It's possible map a physical interface into a container via pipework.
Connect a container to a local physical interface
pipework eth2 $(docker run -d hipache /usr/sbin/hipache) 50.19.169.157/24
pipework eth3 $(docker run -d hipache /usr/sbin/hipache) 107.22.140.5/24
There may be a native way now but I haven't looked into that for the 1.10 release.

Openstack VM is not accessible on LAN

I am facing issue with accessing Open stack VM's on LAN.
I have setup single machine(192.168.2.15) opensatck using devstack, so
all VM's are running inside this machine
My machine(192.168.2.15) has one network card(eth0) and
I have nova networking, have not installed neutron.
I have assigned static IP on eth0 of all the LAN machine( such as 192.168.2.15 and 192.168.2.16) in /etc/network/interfaces file.
System information of the Openstack Machine is as below:
Memory usage: 19% IP address for virbr0: 192.168.122.1
Swap usage: 0% IP address for br100: 10.0.0.1
Below works fine
I can access internet from VM1(10.0.0.2 which is auto assigned IP).
I can ping LAN machine(192.168.2.16) from VM1.
Openstack machine(192.168.2.15) can ping VM1(10.0.0.2).
VM1(10.0.0.2) can ping VM2(10.0.0.3).
But LAN machine 192.168.2.16 is not able to ping VM1(10.0.0.2)
So please suggest how can it be achieved ? And Please consider me as very new to Openstack and networking.
Thanks !!!
You need to assign a floating IP to the VMs you create if you want a host from outside the openstack network to connect to it. The internal IPs are only accessible from inside the openstack network.
See how to assign a floating IP to a VM here: http://docs.openstack.org/user-guide/content/floating_ip_allocate.html
To access the VM's floating IP from another host (that is not the devstack host) you should make sure that the devstack host is configured to forward packets. You can do this with:
sudo bash
echo 1 > /proc/sys/net/ipv4/ip_forward
echo 1 > /proc/sys/net/ipv4/conf/eth0/proxy_arp
iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
See more details here:
http://barakme.tumblr.com/post/70895539608/openstack-in-a-box-setting-up-devstack-havana-on-your
Adding a route to client machine to openstack VM, helped me.

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