topic Re: System Clock Vulnerability in Operating System - HP-UX

System Clock Vulnerability

Kyle D. Harris — Mon, 15 Dec 2003 14:02:05 GMT

Hello all-
I am trying to syncronize my systems clocks with a Straus 2 server that is near me (U of Georgia). It is a easy fix but I get this error:

"Could not establish connection. Either 209.195.3.50 is not availiable or firewall settings on your computer are blocking NTP connections"

I'm Pretty sure it's the firewall. Which goes to my next question, How to I make it so the NTP connections don't get blocked? Thanks!

Kyle

Re: System Clock Vulnerability

RAC_1 — Mon, 15 Dec 2003 14:04:49 GMT

Check port required for ntp is open.

contact ur firewall administrator

ntp uses port 123.

(Check /etc/services file)

Re: System Clock Vulnerability

A. Clay Stephenson — Mon, 15 Dec 2003 14:07:39 GMT

Open up udp port 123. NTP is not considered to be a significant vulnerability.

Re: System Clock Vulnerability

Paula J Frazer-Campbell — Mon, 15 Dec 2003 14:08:24 GMT

Hi

Try a trace route to 209.195.3.50 and see where is stops

Paula

Re: System Clock Vulnerability

Kyle D. Harris — Mon, 15 Dec 2003 14:48:49 GMT

The Port was open. NTP was listed as a "Medium Risk" on my Vulnerability sheet I got.

Re: System Clock Vulnerability

Jeff Schussele — Mon, 15 Dec 2003 14:58:47 GMT

Hi Kyle,

1) Verify the 123/UDP is open in *both* directions.
2) Verify that your host is allowed to connect to the UofG server.
3) Run netstat -an | grep 123 & make sure you have a line like
udp 0 0 *.123 *.*

HTH,
Jeff

Re: System Clock Vulnerability

Kyle D. Harris — Mon, 15 Dec 2003 15:05:39 GMT

What did you mean make sure the port is open in "both" directions??

The traceroute stopped at 30 by the way.

Re: System Clock Vulnerability

Jeff Schussele — Mon, 15 Dec 2003 15:09:23 GMT

By both directions I mean that 123/UDP traffic is allowed out as well as in through the firewall.

And by stopped at 30 do you mean it made 30 hops & then stopped?

If so you have a router out there that's sending you on a bad route. 30 hops is the max allowed for TCP connections.

Are there a bunch that are all the same or a loop i.e. goes to router A & to router B & back to A & back to B & on & on? Then that's the problem.

Rgds,
Jeff

Re: System Clock Vulnerability

Kyle D. Harris — Mon, 15 Dec 2003 15:15:16 GMT

Yes, to 30, then the prompt came back up.