Capture traffic on interface

Capture specific traffic to a pcap file

tcpdump -i eth0 -nn host <ip> and port 80 -w /tmp/capture.pcap
tool
linux133 commands
tags
linuxnetworkdebug

More linux commands

  • Check inode usage
    df -i | sort -k5 -rn

    Show inode usage per filesystem; can cause 'no space' without disk full

  • List open files by process
    lsof -p <pid>

    Show all files, sockets, and connections opened by a process

  • Watch command output
    watch -n 2 'kubectl get pods -n <ns>'

    Re-run a command every 2 seconds with diff highlighting

  • Run command in background
    nohup ./script.sh > /tmp/out.log 2>&1 &

    Run a script immune to SIGHUP; redirect output to file

  • Create SSH tunnel
    ssh -L 8080:internal-service:80 user@bastion -N -f

    Forward local port 8080 to an internal host via bastion

all 133 linux commands