network-alpine/README.md

Network Alpine

Caution

This is only meant to be used inside testing networks. Do NOT use for production!

Just an alpine image with common packages for network troubleshooting installed:

• bash, vim, nano, python3
• jq, pv, git, wget, curl
• curl, openssh, lftp,
• lighttpd, lldpd
• bind-tools (dig), tcpdump
• socat, iperf, iperf3
• nmap, fping

By default a HTTP Server is available on port 80. Change the port with HTTP_SERVER_PORT.

Example Use Cases

# See current IP configuration
ip address
ip route

# Set IP address
ip address add 10.1.1.3/24 dev eth0
ip address add broadcast 10.1.2.255 dev eth0

# Set Gateway
ip route del default
ip route add default 10.1.1.0/24 via 10.1.1.3

# Request new IP address via DHCP
ip addr flush dev eth0
udhcpc -i eth0 -n -q

# Set DNS
nano /etc/resolv.conf # Update line "namesperver x.x.x.x"

# Query DNS
dig example.com A @10.1.1.3

# List LLDP neighbors
lldpcli show neighbors

# Ping a host
ping -I eth0 10.1.1.3

# Send HTTP Request
curl http://10.1.1.3 -v

# Connect somewhere via SSH
ssh user@10.1.1.3 -p 22
# Copy file via SFTP
scp file.txt user@10.1.1.3:~

# Interactively browse FTP server
lftp ftp://user@10.1.1.3

# Connect to a TCP port
nc 10.1.1.3 80

# Scan for open TCP ports
nmap -sT -p 22-10000 10.1.1.3

# Ping all IPs in the network
fping -g -r 1 -q -a 10.1.1.0/24

# Capture network traffic
tcpdump                         # Capture ALL traffic
tcpdump -i eth0 icmp            # Filter for ICMP traffic
tcpdump -i eth0 -w capture.pcap # Write to file
tcpdump -r capture.pcap         # Read from file

# Test unicast bandwidth
iperf3 -s               # Setup server on host 10.1.1.2
iperf3 -c 10.1.1.2      # Check TCP downlink from 10.1.1.2
iperf3 -c 10.1.1.2 -u   # Check UDP downlink from 10.1.1.2

# Test multicast connectivity (with iperf)
iperf -s -u -B 224.0.67.67 -i 1                 # Setup multicast receiver
iperf -c 224.0.67.67 -u --ttl 5 -t 10 -b 1M     # Send for 10 seconds at 1 MBit/s
# Test multicast connectivity (with socat)
seq 50 | xargs -Iz echo "Hello World" | pv -qL 2 | socat -u - UDP4-DATAGRAM:239.255.10.10:5000,ip-multicast-ttl=1 # Sender
socat -u UDP4-RECV:5000,ip-add-membership=239.255.10.10:0.0.0.0 -   # Receiver