Re: Strange Network Problem (TTL?)
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.
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