On Thu, Mar 09, 2000 at 04:26:26AM -0500, Chris Wagner wrote: > What precisely is the TTL when it comes to pings? And what do you mean by > "open DNS"? >
Ping will show you the TTL of the returning icmp packet. I can't tell you exactly what the TTL does on the iron where the ping packet will bounce. Cisco and (most?) *nix will set the TTL of the icmp echo-reply to 255, but I think this depends on the implementation of the IP stack. When I say 'open dns', I mean that you can do full zone transfers. This is usually blocked by filtering 53-TCP or by denying it in the BIND config because most people consider this as a security hole of your network. Paul.
