I'm redirecting tcpdump output from machine A to machine B. A and B must use a "secure" connection, using VPN or ssh tunnel. I only care about authentication, however: I don't need to protect from sniffing data.
How much overhead should I expect using VPN/ssh compared to a "plain" connection? Bandwidth is a non issue for me, but CPU overhead is.
(If you are wondering the "redirection" happens starting tcpdump with telnet on vpn or ssh on a plain connection)