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 Subject :How do routers get their time from Internet NTP.. 2014-08-31- 01:31:24 
N4SV
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Joined: 2014-04-08- 19:54:23
Posts: 23
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According to the descriptions, when a node is connected to the Internet it will automatically get its time from an NTP server (default is us.pool.ntp.org).  Will this NTP access propagate to other nodes on the mesh?  Mine don't seem to be syncing their time to an NTP server on the WAN so I wanted to understand a bit more about how this NTP sync should work, and maybe I could figure out why mine aren't.
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 Subject :Re:How do routers get their time from Internet NTP.. 2014-08-31- 03:46:17 
KF5JIM
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Joined: 2013-07-17- 12:13:36
Posts: 250
Location: Nederland

You need to enable "mesh gateway" on the node that is plugged into an active internet connection before the other nodes can communicate with an NTP server.
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My opinions and views expressed here are solely my own.
 Subject :Re:How do routers get their time from Internet NTP.. 2014-09-02- 01:11:48 
N4SV
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Guess I should have been more specific; access to the WAN port and beyond is working fine, in fact devices connected to the node which has it's WAN gateway activated, as well as devices on other nodes in the mesh, all get their time sync OK. I've got computers and VoIP phones across the mesh which can see the NTP time service just fine. It's just the nodes themselves that will not update their time against the NTP sync source. So I was looking for some detail in just how the NTP propagates across the mesh to understand why the nodes won't sync. I've tried changing the NTP source in the NTPCLIENT file from US.POOL.NTP.ORG to things like TICK.USNO.NAVY.MIL (also tried TOCK), but still the nodes will not update. I know I can manually set the time from within BusyBox, but I was hoping to have it be automatic and all nodes syncing to the same source.
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 Subject :Re:How do routers get their time from Internet NTP.. 2014-09-02- 03:04:37 
VE3RTJ
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Joined: 2013-08-19- 07:21:12
Posts: 49
Location: Hamilton, Canada FN03

The node's default is to go out a gateway to the specified ntp site. Without a gateway, the nodes don't seem to be able to sync up amongst themselves. I don't want to have to fiddle with every node's ntp config file to have them point to a specific node. That would require a manual setup for every deployment.

 

Just out of curiosity, could this be spoofed by adding an advertised service or named host with the ntp host named in the config file? ie, add a computer or gps time server to the mesh via a node, and give it a host name equivalent to the one the ntp clients are looking for? If a gateway isn't available, none of the nodes should be able to look at an internet DNS...

 

Think I just found next weekend's project.

 

Hmm. Re-read your post and think I missed the point. Sounds like your nodes aren't going out to get time updates, but devices connected to them are successfully updating. I haven't had that issue; every time I connect a node to a mesh with a gateway, the first thing that happens is it updates it's own time. I haven't updated yet, all my nodes are V 1.0. I've been interested in getting NTP working across a mesh without a gateway.
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Last Edited On: 2014-09-02- 03:13:08 By VE3RTJ for the Reason
73 de Ron P. email: (callsign) *at* gmail.com
 Subject :Re:How do routers get their time from Internet NTP.. 2014-09-05- 02:06:56 
N4SV
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Joined: 2014-04-08- 19:54:23
Posts: 23
Location: 
Ron, your re-read comment is the correct one; devices on the mesh are getting their time OK, just not the nodes themselves. And actually your comment about spoofing...that is actually what I am doing. I have the WAN port of one mesh node set as a gateway but instead of it looking at the Internet it is looking at a server running various applications and services to test, like DNS and NTP. I've modified the NTPCLIENT file on all of my nodes to look to that server for NTP rather than the default us.pool.ntp.org. To get this "faux-internet" to propagate to the rest of the mesh I had to modify the OLSRD.CONF file to add my external server IP as one of the default PING targets it uses to determine if it is actually on the Internet. So the Internet-spoofing is mostly working, my mesh is completely fooled into routing all the non-mesh traffic out the WAN port of my gateway node, and all devices on the LANs of the mesh nodes are getting their time sync from my external NTP server. But for some reason the nodes themselves aren't buying into my faux-Internet, at least related to NTP. Other traffic is routing fine, just not NTP updates to the nodes. So there is some other process at work here that I need to discover. By the way, I also tried putting the NTP server inside the mesh, placing it on a LAN port of one of the mesh nodes, and I couldn't convince the nodes to update their time from that either. 73, Bill, N4SV
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 Subject :Re:How do routers get their time from Internet NTP.. 2014-09-05- 02:52:36 
VE3RTJ
Member
Joined: 2013-08-19- 07:21:12
Posts: 49
Location: Hamilton, Canada FN03

I was rummaging around inside a node the other night, and ran across quite a few NTPCLIENT files. I never did find a .conf file. I did find what looked like a perl script (maybe just a shell script) that included a NTPCLIENT call and a ping to the .pool ntp server address. It looked like it was intended to ping out to the world, and if it got a response, it would call the NTPCLIENT program, otherwise it would loop. It wasn't the olsrd.conf fiile, I'm pretty sure of that.  I'm sorry, I can't remember where I found it, but I found it by searching for NTP using WINSCP while connected to the node.

 

Just shooting in the dark, but perhaps the node won't look for ntp services if it doesn't see a path to a particular address? Perhaps if you could find that routine and plug in your servers' address...

 

I have to ask; what's the importance of setting the time on the nodes themselves? Aside from displaying on the admin pages, the node time doesn't seem to have any impact on the mesh. If I don't have a gateway up, my nodes usually show random times, and I haven't noticed any negative effects. I have to admit you've piqued my curiosity, but is there a practical consideration?
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73 de Ron P. email: (callsign) *at* gmail.com
 Subject :Re:How do routers get their time from Internet NTP.. 2014-09-25- 01:59:14 
N4SV
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Joined: 2014-04-08- 19:54:23
Posts: 23
Location: 
Good question Ron, and of course the answer is there is little value in having the time set in the nodes. But it's just one of those things that bugs me and I have this need to get it to work...really to understand how it works. In general your comments is right on, the node, once the WAN gateway is activated, is designed to PING certain known systems on the Internet (like you I don't remember what file that is in, but I know it is there). So all I did was add the IP of my spoof-Internet machine to the list. It seems to have worked as all nodes on my small mesh network see that as the path to the Internet. But the nodes themselves aren't buying it; maybe its because they won't interface to a Microsoft NTP server, which is the NTP I have running in my spoof-Internet. The LAN clients on the various mesh nodes all seem to like it for NTP, just not the nodes themselves. So again, no real value at all, just something I have a desire to get working and understand how it works, HI.
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 Subject :Re:How do routers get their time from Internet NTP.. 2014-09-26- 03:31:07 
AD7QF
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Joined: 2012-04-16- 05:51:12
Posts: 23
Location: 
Take a look at "NTP server" under Applications, where I describe in brief detail how I did it. While still under test. My applience seems to be doing the job. It is awsome to see the other nodes on the mesh sync their time. The best part is, as an applience, it is plug and go. Under specific situtations, this is really great. Because of this, the other node operators do not have to do anything, other then turn them on.
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