[time] Summary: icmp reachability?

[ntpadmin at oc9.com]

On Wed, 21 Mar 2007, Jeffrey Goldberg wrote:

> The short summary is that yes it is important to allow many kinds of
> ICMP messages through from smooth Internet operation.
>
> In particular, the message types 0, 3, 4, 8, 11, 12 are the most useful.
>
> ICMP, very broadly speaking, provides a mechanism for reporting
> failures of TCP and UCP packets.  Failure in getting these message
> through can lead to (most commonly) very long timeouts and other
> connectivity problems.  Full details are in the RFCs.
>
> None of this is specific to NTP, but is an IP thing in general.
>
> The reasons for blocking ICMP, Ping of Death, are well outdated.
>
> I'd like to thank everyone who took to time to educate me on these
> matters.
>
> -j

Very interesting summary indeed. I will refresh my memory be looking at 
what 0, 3, 4, 8, 11, 12 are for.

I am glad the ntp list helped you out!

-Louis,