[ntp:questions] Re: Setting up a synchronization network

Maarten Wiltink maarten at kittensandcats.net
Sat Jan 17 12:12:05 UTC 2004

"Richard B. Gilbert" <rgilbert88 at comcast.net> wrote in message
news:FaKdnay3qL7WJZXdRVn-ig at comcast.com...
> The address Comcast gave me was  When it proved
> unreachable, I looked up  the owner and found it assigned to the IANA.

It's not so much unreachable as unrouteable. This is in one of
three ranges that are "reserved for private/local use". See RFC
1918. In effect, you can use those addresses on your own networks
but you mustn't let anybody on the outside know. I run my network
on 192.168.27/24 (I live at no. 27) but packets destined to cross
public networks are "masqueraded" on exit and translated back on
re-entry, so all my public traffic uses a public address for the

What it means is that apparently, they do have an NTP server on
their internal network, and they've been asked before and it
slipped into the helpdesk knowledge base somehow. But that's no
use to you because even if you told your router that 172.16/12
is on your ISP's network, they'll probably be filtering return
traffic from that range.

Maarten Wiltink

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