Wireshark and tcpdump Reference

Wireshark and tcpdump are extremely powerful network troubleshooting tools. Here are some command examples that may be useful.

Wireshark Display Filters

Show all ARP:
Show ARP from a specific MAC:
arp.src.hw_mac == 00:16:D3:4A:CE:7D
Show all traffic to a specific IP:
ip.src ==
Show all traffic to/from a specific IP:
ip.addr ==
Show only SYN packets:
Show all web traffic:
tcp.port == 80

OpenSSL Tips & Tricks

Get into the correct directory:

cd /etc/pki/tls/certs

Generate key

openssl genrsa -des3 -out mike.key 4096

chmod 600 mike.key

Generate signing request

openssl req -new -key mike.key -out mike.csr

chmod 600 mike.csr

Get the CA to sign the request

openssl x509 -req -days 10000 -in mike.csr -out mike.cert \

-CA /etc/pki/tls/certs/ \