Re: sntpclock: fatal: time uncertainty too large
"Martin A. Brown" <[email protected]> Tue, 25 Mar 2003 23:13:57 -0600 (CST)
| Newsgroups | gmane.comp.lib.libtai |
|---|---|
| Message-ID | <[email protected]> |
Shantanu, You need to ensure that the following outbound packet signature is accepted by any upstream packet filtering device(s): UDP client:ephemeral --> ntp-server:123 Where ephemeral ports are ports between 1024 and 65535. You will also need to ensure that you are allowing the return packets into the NTP client machine. UDP ntp-server:123 --> client:ephemeral If any upstream device blocks the outbound UDP packet or the reply, you will not be able to use sntpclock to synchronize. Be certain to use tcpdump, or some other network analysis tool to ensure that the packets are not denied on return from the remote server. If you are using a distribution, such as RedHat, which includes host-level packet filters by default, you may wish to alter these packet filters and/or remove the filter entirely (at your own risk). If you are unlucky enough to have an ISP which is actually blocking traffic (strange indeed, but not inconceivable), I would recommend that you contact them and request that they desist or that they provide you with an accurate NTP server. Good luck, -Martin : When i try to run : # sntp clock <ip> | clockview : sntpclock: warning: unable to read clock: timed : out : sntpclock: warning: unable to read clock: timed : out : sntpclock: warning: unable to read clock: timed : out : sntpclock: warning: unable to read clock: timed : out : sntpclock: warning: unable to read clock: timed : out : sntpclock: warning: unable to read clock: timed : out : sntpclock: warning: unable to read clock: timed : out : sntpclock: warning: unable to read clock: timed : out : sntpclock: fatal: time uncertainty too large : clockview: fatal: data split across packets : : It is not that my clock is too screwed. : # date : Wed Mar 26 10:22:48 IST 2003 : # hwclock : Wed 26 Mar 2003 10:23:48 AM IST 0.992516 seconds : : Still i get this error. I tried with quite a few : NTP servers. Same problem. : One thing I must say here is that my ISP blocks : by default many ports. Does clockspeed require : any port to be kept open? : : Thank you. : Shantanu : : : : __________________________________________________ : Do you Yahoo!? : Yahoo! Platinum - Watch CBS' NCAA March Madness, live on your desktop! : http://platinum.yahoo.com : -- Martin A. Brown --- SecurePipe, Inc. --- [email protected]