The IPs in the 1st two lines of ntp.conf are 127.127.1.0. Is that correct, or should they be 127.0.0.1? The latter seems to work but I am dubious concerning the 1st one. -- ...CH "Home is the place you can scratch where it itches."
On Saturday 07 August 2004 12:36 am, C Hamel wrote:
The IPs in the 1st two lines of ntp.conf are 127.127.1.0. Is that correct, or should they be 127.0.0.1?
It should be 127.0.0.1 (the loopback device ip, e.g. localhsot)...but why do you have that ip there? There should be the ip address of the NTP servers your machine is going to connect to... or are you serving some ntp clients?
On Aug 7 at 12:43am, Jorge Fábregas wrote:
On Saturday 07 August 2004 12:36 am, C Hamel wrote:
The IPs in the 1st two lines of ntp.conf are 127.127.1.0. Is that correct, or should they be 127.0.0.1?
It should be 127.0.0.1 (the loopback device ip, e.g. localhsot)...but why do you have that ip there? There should be the ip address of the NTP servers your machine is going to connect to... or are you serving some ntp clients?
The address 127.127.1.0 is indeed correct. If one reads the beginning lines of the default /etc/ntp.conf, there is an explanation: ## Radio and modem clocks by convention have addresses in the ## form 127.127.t.u, where t is the clock type and u is a unit ## number in the range 0-3. ## ## Most of these clocks require support in the form of a ## serial port or special bus peripheral. The particular ## device is normally specified by adding a soft link ## /dev/device-u to the particular hardware device involved, ## where u correspond to the unit number above. ## ## Generic DCF77 clock on serial port (Conrad DCF77) ## Address: 127.127.8.u ## Serial Port: /dev/refclock-u [...] ## ## Undisciplined Local Clock. This is a fake driver intended for backup ## and when no outside source of synchronized time is available. ## server 127.127.1.0 # local clock (LCL) fudge 127.127.1.0 stratum 10 # LCL is unsynchronized If you want to reference a real ntp server, you must include the IP address of each as indicated in the remainder of the config file (tho' you can also include the dns name): ## ## Outside source of synchronized time ## ## server xx.xx.xx.xx # IP address of server server tock.cs.unlv.edu #### for example Jim Cunning
On Saturday 07 August 2004 00:37, Jim Cunning wrote: <SNIP>
The address 127.127.1.0 is indeed correct. If one reads the beginning lines of the default /etc/ntp.conf, there is an explanation:
<SNIP EXAMPLE>
server 127.127.1.0 # local clock (LCL) fudge 127.127.1.0 stratum 10 # LCL is unsynchronized
If you want to reference a real ntp server, you must include the IP address of each as indicated in the remainder of the config file (tho' you can also include the dns name):
## ## Outside source of synchronized time ## ## server xx.xx.xx.xx # IP address of server server tock.cs.unlv.edu #### for example
Jim Cunning Again, I read [somewhere <SIGH>] that it should be the loopback device ...consequently, the confusion. Aren't examples just that... examples (If I followed the example for my network address it might not resemble what I am using)?
As long as my clock is being kept up to date I suppose I really shouldn't care, but I would like to know the 'whys & wherefores' so I can educate myself a little more. -- ...CH "Home is the place you can scratch where it itches."
On Saturday 07 August 2004 16:30, C Hamel wrote:
Again, I read [somewhere <SIGH>] that it should be the loopback device
It is the loopback device. All addresses starting with 127 will be resolved as loopback. It can be 127.0.0.1 or it can be 127.35.14.6. Try pinging 127.127.10.0 while running something like tcpdump. The pings will never leave your machine
On Saturday 07 August 2004 09:37, Anders Johansson wrote:
On Saturday 07 August 2004 16:30, C Hamel wrote:
Again, I read [somewhere <SIGH>] that it should be the loopback device
It is the loopback device. All addresses starting with 127 will be resolved as loopback. It can be 127.0.0.1 or it can be 127.35.14.6. Try pinging 127.127.10.0 while running something like tcpdump. The pings will never leave your machine So it is the 1st octet that determines this, apparently. Thanks for the explanation. -- ...CH "Home is the place you can scratch where it itches."
CH, On Saturday 07 August 2004 09:10, C Hamel wrote:
On Saturday 07 August 2004 09:37, Anders Johansson wrote:
...
It is the loopback device. All addresses starting with 127 will be resolved as loopback. It can be 127.0.0.1 or it can be 127.35.14.6. Try pinging 127.127.10.0 while running something like tcpdump. The pings will never leave your machine
So it is the 1st octet that determines this, apparently. Thanks for the explanation.
It's an old-fashioned (class-based) class A address: The host number occupies 7 bits of the first byte of the IP addressand the host number is the other 24 bits (the last three bytes) of the IP address.
-- ...CH "Home is the place you can scratch where it itches."
Randall Schulz
Today at 9:30am, C Hamel wrote:
On Saturday 07 August 2004 00:37, Jim Cunning wrote: <SNIP>
The address 127.127.1.0 is indeed correct. If one reads the beginning lines of the default /etc/ntp.conf, there is an explanation:
<SNIP EXAMPLE>
server 127.127.1.0 # local clock (LCL) fudge 127.127.1.0 stratum 10 # LCL is unsynchronized
If you want to reference a real ntp server, you must include the IP address of each as indicated in the remainder of the config file (tho' you can also include the dns name):
## ## Outside source of synchronized time ## ## server xx.xx.xx.xx # IP address of server server tock.cs.unlv.edu #### for example
Jim Cunning Again, I read [somewhere <SIGH>] that it should be the loopback device ...consequently, the confusion. Aren't examples just that... examples (If I followed the example for my network address it might not resemble what I am using)?
As long as my clock is being kept up to date I suppose I really shouldn't care, but I would like to know the 'whys & wherefores' so I can educate myself a little more.
I surmise from your earlier responses to others on the list, you are not planning to run an ntp server--you are just trying to keep your clock accurate. If that's the case, you can leave the "server" and "fudge" entries for 127.127.1.0 alone. They are correct as written, and as Anders indicates are loopback addresses. But, you must add either the IP address or FQDN of some outside time server in /etc/ntp.conf, or you will be synchronizing to yourself (and thus, running xntpd is pointless). For a list of network time servers and other information, go to http://www.ntp.org. You also can peruse the information in the xntp-doc package at /usr/share/doc/packages/xntp-doc if you have it installed. Jim
I surmise from your earlier responses to others on the list, you are not planning to run an ntp server--you are just trying to keep your clock accurate. If that's the case, you can leave the "server" and "fudge" entries for 127.127.1.0 alone. They are correct as written, and as Anders indicates are loopback addresses.
But, you must add either the IP address or FQDN of some outside time server in /etc/ntp.conf, or you will be synchronizing to yourself (and thus, running xntpd is pointless). For a list of network time servers and other information, go to http://www.ntp.org. You also can peruse the information in the xntp-doc package at /usr/share/doc/packages/xntp-doc if you have it installed.
Jim I *do* understand that I need outside IPs for time synch, and have seven in
On Saturday 07 August 2004 09:56, Jim Cunning wrote: <SNIP> place. ;-) Thanks! -- ...CH "Home is the place you can scratch where it itches."
On Friday 06 August 2004 23:43, Jorge Fábregas wrote:
On Saturday 07 August 2004 12:36 am, C Hamel wrote:
The IPs in the 1st two lines of ntp.conf are 127.127.1.0. Is that correct, or should they be 127.0.0.1?
It should be 127.0.0.1 (the loopback device ip, e.g. localhsot)...but why do you have that ip there? There should be the ip address of the NTP servers your machine is going to connect to... or are you serving some ntp clients? The time synchs are for this box, only. -- ...CH "Home is the place you can scratch where it itches."
I'm not sure about the first one, and I doubt it is correct. It would make more sense if it was a multicast address 224.x.x.x, but those type of NTP requests are usually passively listened to rather than actively requested. Out of curiosity, did you put these lines in there or did another program do it? ______________________________ Justin Grote Network Architect, CCNA JWG Networks Email: nospam-justin@grote.name (remove nospam-) SMS: nospam-rastan@vtext.com (remove nospam-) Phone: (208) 631-5440 ------------------------------ Original Message Follows ------------------------------ CH> The IPs in the 1st two lines of ntp.conf are 127.127.1.0. Is that correct, or CH> should they be 127.0.0.1? The latter seems to work but I am dubious CH> concerning the 1st one. CH> -- CH> ...CH CH> "Home is the place you can scratch where it itches."
I'm not sure about the first one, and I doubt it is correct. It would make more sense if it was a multicast address 224.x.x.x, but those type of NTP requests are usually passively listened to rather than actively requested.
Out of curiosity, did you put these lines in there or did another program do it?
______________________________ <SNIP> The original lines were '227.227.1.0'... though I read, somewhere, that this should be the loopback address so I had changed it to 127.0.0.1 to reflect
On Friday 06 August 2004 23:46, Justin Grote wrote: that. -- ...CH "Home is the place you can scratch where it itches."
I'm not sure about the first one, and I doubt it is correct. It would make more sense if it was a multicast address 224.x.x.x, but those type of NTP requests are usually passively listened to rather than actively requested.
Out of curiosity, did you put these lines in there or did another program do it?
______________________________ <SNIP> Hmmm did I get an echo? At any rate, I put the loopback address there since
On Friday 06 August 2004 23:46, Justin Grote wrote: the original address was not the loopback device & I read that it was supposed to be the loopback --though I really do not recall where I read that, at the moment. -- ...CH "Home is the place you can scratch where it itches."
participants (6)
-
Anders Johansson -
C Hamel -
Jim Cunning -
Jorge Fábregas -
Justin Grote -
Randall R Schulz