Docker Networking Toolkit

Originally created by @someguy123 (Github | Steemit)

Licensed under the MIT license (See LICENSE)

Docker Hub: someguy123/net-tools

This is a docker image which builds Ubuntu 18.04 LTS with various networking tools pre-installed, for debugging networks.

It was created as Ubuntu's docker image contains absolutely no networking tools, not even the most basic ifconfig, route, or ip. This makes it practically useless for basic networking tasks.

Originally developed for GNS3 (network prototyping tool), this container is perfect for troubleshooting and testing your GNS3 topology using the built-in Docker support. No need to set up bloated Linux VMs, just type into the image selection box someguy123/net-tools and you're ready to debug your network.

As this image is likely to be used directly from it's console, bash-completion and command-not-found are both included, plus a colorised bash prompt with timestamps.

Basic utilities such as tmux, screen, vim and nano are also included, making this image feel more like a normal VM, rather than a barebones docker container.

Quickstart

A pre-built binary image is available on Docker Hub.

docker pull someguy123/net-tools
docker run --name nettools -p 127.0.0.1:2222:22 -itd someguy123/net-tools
# password: net
ssh root@127.0.0.1 -p 2222

More detailed information on how to use this image, including how to use it in GNS3 (network prototyping tool) is available further down.

What's included

• bash-completion - to make bash tab completion better
• command-not-found - when you type a command that doesn't exist, it informs you of which package a command is in
• mtr-tiny - fast and easy to read realtime traceroutes for both IPv4 and IPv6 (tiny version skips all the GTK bloat)
• dnsutils - provides tools such as dig and nslookup for DNS debugging
• net-tools - basic networking tools such as ifconfig, netstat, route, arp
• dhclient - DHCP client from isc-dhcp-client package
• nmap - port scanning and other network reconnaissance
• traceroute - self explanatory. alternative to mtr
• netcat - nc tool. highly versatile TCP/UDP/unixsocket client and server
• iproute2 - provides the ip and bridge tools for advanced network configs
• tcpdump - similar to wireshark, but CLI based. for inspecting network packets
• iputils-ping - for the ping command. supports both IPv4 and v6 in the same binary, instead of ping + ping6
• openssh - server and client. for testing ssh connectivity, and so you may ssh into the container for a better experience
• tmux - run multiple things in one terminal session, with tabs and split windows
• screen - similar to tmux, for running things in the background
• vim/nano - for times when you need a text editor. remember! don't expect files on a container to be persisted. use a volume.

Usage

Standard Docker

Pull the image from Docker hub

docker pull someguy123/net-tools

Launch the docker image, with the SSH port forwarded. SSH will offer a better terminal experience than docker's TTY

NOTE: Please be careful with your docker port forwards. The SSH password is only 3 characters (net), there is no firewall inside of the container, and there is no rate limiting such as fail2ban.

Your container could be compromised if the SSH port is exposed to the internet carelessly.

docker run --name nettools -p 127.0.0.1:2222:22 -itd someguy123/net-tools

Now you can SSH into the container, use the username root and the password net

ssh root@127.0.0.1 -p 2222

root@127.0.0.1's password:
Welcome to Ubuntu 18.04.1 LTS

04:05:59 32b9bd38c2f9:~ # ping 8.8.4.4
PING 8.8.4.4 (8.8.4.4) 56(84) bytes of data.
64 bytes from 8.8.4.4: icmp_seq=1 ttl=37 time=16.8 ms
64 bytes from 8.8.4.4: icmp_seq=2 ttl=37 time=16.3 ms

Alternatively you can use the container without logging into SSH, just remove -p 127.0.0.1:2222:22, and use docker to launch a shell:

docker exec -it nettools bash

For GNS3

Open the settings, go to Docker>Docker Containers, click the "New" button, select whether you're using a local or remote GNS3 server, and then it will ask you for a docker image. Click "New Image" and enter someguy123/net-tools.

It will ask you to name it, and select how many adapters you would like. Fill those out as you want.

When it asks for a "start command", simply leave the box blank. By default the container starts a bash shell, so that it's usable out of the box via the console menu option in your topology.

Leave the console type as telnet. You can also leave the environment options blank.

You should now have an appliance called someguy123-net-tools (or whatever you changed the name to).

In your GNS3 project, you'll find the docker image under "End Devices" (the monitor icon). Simply drag it into your topology, and connect it as you would any other device.

After placing it on the topology, connecting it to your network, and then pushing "Start", you'll be able to access the console just like other devices in GNS3. You also have easy access to /etc/network/interfaces just by clicking the Configure menu item.

For a better experience, you should be able to connect via SSH to any configured IP addresses. Configure the networking through the Configure menu (will restart the container), or using standard Linux network tools (ip, ifconfig and route are all available). Be warned that persistence is not guaranteed with docker, files such as configurations may get wiped out when the container is shutdown in GNS3.

Manual Build

If you need to customise the image, you can build it manually:

git clone https://github.com/someguy123/docker-networktools
cd docker-networktools
docker build . -t nettools

You can then use the image nettools with docker run -itd nettools as previously shown.

Has this project helped you?

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