Using Snort Stealthily
jukal writes "Linux Journal has an article on using Snort as stealth sniffer, a stealth NDIS probe and stealth loger -- on a network interface with no IP address. 'Snort is a versatile and powerful tool for sniffing, intrusion detection and packet logging. Configuring it to run stealthily in sniffing mode or NIDS mode is easy; incorporating it into a stealth-logging solution is only slightly less so'"
When I want to snort, I use a little alcohol solution in an Afrin bottle -- very inconspicuous.
Oh, and it hurts!