Important flags
- -n to disable (per-packet blocking) DNS lookups
- -s snaplen to capture more than the default snapshot length. 0 for no limit.
- -e to show link-layer information
Recipes
- Capture all arp: tcpdump arp
- Capture packets to or from a MAC address M: tcpdump ether host M
Gotchas
- tcpdump will not function on a DPDK interface once a DPDK application has bound the interface
- A filter matching L4 fields (including TCP/UDP port) will not match any fragments save the first. Watch for [+] to indicate more fragments.