Re: [time-nuts] GPS, NTP, and Cisco routers...
I remember running this on line aux 0 in the IOS version 11.x days (circa 1999). Was supported on the 7000, 4000 and 2500 series routers. It was originally designed for a Telecom Solutions (bought by Symmetricom) clock that would be co-located with the routers in a data centre . I have a PDF copy of Application Note 600 that shows how it was intended to be used (mail me if you need a copy). I ditched the solution in favour of a FreeBSD+GPS based solution; Cisco was (and still is) only supporting version 3 of NTP specification. I do not have any data left on how well it worked but I recall it was better with the PPS support than without. Regards. Mark. -- Mark Allwright CCIE #1088 National Hosting Services - Senior Data Analyst 2100 111 - 5th Avenue SW Calgary, AB T2P 3Y6 T: 403 410-0733 | F: 403 216-6050 -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Scott Mace Sent: Sunday, October 05, 2008 11:33 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] GPS, NTP, and Cisco routers... This runs on the aux port, and the sup720 doesn't have an aux port... There are always obscure features that slip into the production releases that aren't tested and they just forget to exclude them during builds. TAC will probably have no clue about this... You could try the cisco-nsp mailling list for support, but beware, it's frequented by cisco developers that will just as soon open a bug-id to drop 'feature' from the production release if it was never supposed to be there in the first place. I wonder if this was originally used as an alternative method to time the MIX midplane in the VXR chassis and the NTP feature was side benefit? Most telecom gear that needs synchronization will take a BITS input or some other frequency reference. I've used that extensively with SONET gear and the good old Datum OT-21. I never used the 7200 MIX, so I'm not sure if it could take an external reference or just recover clock from a DS1 port. Seems like a good use for an AUX port if you don't need a modem or reverse telnet! Scott Scott McGrath wrote: Actually you might get pretty good results if you have a 6509 as any activity on the serial port triggers a CPU interrupt which is why on a overloaded 6509 the first thing to try is no logging console to get the cpu down from 100% - usually in the context of DDoS and the control plane is slammed as the EOBC is only a 1 megabit channel even on the 3BXL's.This is one of the advantages of the annual trek out to Bldg 14 in San Jose - one gets to meet the guys who developed the code for the routers. This has more than passing interest for me as one could take a NovaTel GPSCard which has a 1PPS output and runs on a single 12-36V supply and has a dedicated 1PPS output at serial levels and install one at each router location.Still have not disassembled the 2501 and 2611 to see which cheapo TCXO Cisco has installed. What do you have available at your shop - we are running SUP720-3BXL's running 12.2 SXF On Sun, Oct 5, 2008 at 1:00 AM, Dave hartzell [EMAIL PROTECTED] wrote: Looks like Trimble and Cisco got together on a PPS implementation for the 7200, starting with 12.0T trainwreck: http://www.cisco.com/en/US/docs/ios/12_1t/12_1t1/feature/guide/dtrimb le.html Since I don't have any 7200s any longer (thank goodness), I checked and it seems that the 6500s support this as well on the console serial port: 6509-rtr(config-line)#ntp ? pps-discipline Use PPS pulse to discipline system clock refclockNTP Reference Clock and 6509-rtr(config-line)#ntp refclock ? telecom-solutions Telecom Solutions GPS trimbleTrimble Navigation TSIP Protocol It looks interesting, and if the code is just looking for a PPS transition on the CTS or RI, you might be in luck with any external PPS... BUT be forewarned, IOS is a cooperative multitasking operating system (at least prior to the new modular stuff), so your accuracy is going to vary depending on loads, processes, etc. I wouldn't count on this being to spectacular... probably no better than an external NTP source. And of course, you can always call the TAC for more assistance! ;-) 73, Dave AF6KD On Fri, Oct 3, 2008 at 2:39 PM, Robert Vassar [EMAIL PROTECTED] wrote: I've been fiddling around with an old Cisco router here at the house to brush up. We have an IPv6 project going at work, and our WAN provider provides no native transit, so I'm looking at doing some tunneling. Anyhow... I discovered IOS 12.1 and above have native NTP capability. I don't have the exhaustive IOS command reference, and I suspect it's a limited NTP implementation. I'm wondering if it's possible to tie a GPS unit to a router serial port and gain a stratum 0 refclock. Any Cisco guru's on the list? :-) Cheers, Rob ___ time
Re: [time-nuts] GPS, NTP, and Cisco routers...
It looks like the feature set varies significantly with the router model, and by IOS feature set. The router I have here is an eBay special, an old 2514. It's probably 10 years old, though I think Cisco continued to make them until about 2003. It's only configured with 8mb flash, so it can only run the stripped down IP subset. (which lacks the IPv6 stuff I need too...) Every few years I dabble with ploughing thru the CC** tests, but I'm a QA engineer, so it never becomes a priority. It's running c2500-i-l.121-27b.bin, and my ntp menu looks quite different: Router2#config t Enter configuration commands, one per line. End with CNTL/Z. Router2(config)#ntp ? access-groupControl NTP access authenticateAuthenticate time sources authentication-key Authentication key for trusted time sources broadcastdelay Estimated round-trip delay clock-periodLength of hardware clock tick master Act as NTP master clock max-associationsSet maximum number of associations peerConfigure NTP peer server Configure NTP server source Configure interface for source address trusted-key Key numbers for trusted time sources Router2(config)#^Z No refclock option. If I had a 16mb flash card, I could run the Enterprise image, which might have different features. But a 16mb flash card and FPM SIMM cost more than this router is worth. It appears to be NTP v3 as well, though all my Solaris boxes run v3 due to some issues with NTP 4.x and the kernel clock code. (It's being fixed...) I'll have to look at one of the newer models I have in the lab at work. I've also been thinking of buying an 851w for my DSL line here at the house. I've outgrown my WRT54G, even running Tomato, perhaps I'll be pleasantly surprised. I hadn't even looked at Cisco stuff since 2002 or so, certainly pre-12.1 anyway. I was just kind of surprised to come across an NTP server at all, and I was curious what its Time-Nuts hackability rating was. :-) Thanks and 73, Rob KC6OOM/5 On Oct 5, 2008, at 12:00 AM, Dave hartzell wrote: Looks like Trimble and Cisco got together on a PPS implementation for the 7200, starting with 12.0T trainwreck: http://www.cisco.com/en/US/docs/ios/12_1t/12_1t1/feature/guide/ dtrimble.html Since I don't have any 7200s any longer (thank goodness), I checked and it seems that the 6500s support this as well on the console serial port: 6509-rtr(config-line)#ntp ? pps-discipline Use PPS pulse to discipline system clock refclockNTP Reference Clock and 6509-rtr(config-line)#ntp refclock ? telecom-solutions Telecom Solutions GPS trimbleTrimble Navigation TSIP Protocol It looks interesting, and if the code is just looking for a PPS transition on the CTS or RI, you might be in luck with any external PPS... BUT be forewarned, IOS is a cooperative multitasking operating system (at least prior to the new modular stuff), so your accuracy is going to vary depending on loads, processes, etc. I wouldn't count on this being to spectacular... probably no better than an external NTP source. And of course, you can always call the TAC for more assistance! ;-) 73, Dave AF6KD On Fri, Oct 3, 2008 at 2:39 PM, Robert Vassar [EMAIL PROTECTED] vassar.com wrote: I've been fiddling around with an old Cisco router here at the house to brush up. We have an IPv6 project going at work, and our WAN provider provides no native transit, so I'm looking at doing some tunneling. Anyhow... I discovered IOS 12.1 and above have native NTP capability. I don't have the exhaustive IOS command reference, and I suspect it's a limited NTP implementation. I'm wondering if it's possible to tie a GPS unit to a router serial port and gain a stratum 0 refclock. Any Cisco guru's on the list? :-) Cheers, Rob ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/ listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/ time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS, NTP, and Cisco routers...
This runs on the aux port, and the sup720 doesn't have an aux port... There are always obscure features that slip into the production releases that aren't tested and they just forget to exclude them during builds. TAC will probably have no clue about this... You could try the cisco-nsp mailling list for support, but beware, it's frequented by cisco developers that will just as soon open a bug-id to drop 'feature' from the production release if it was never supposed to be there in the first place. I wonder if this was originally used as an alternative method to time the MIX midplane in the VXR chassis and the NTP feature was side benefit? Most telecom gear that needs synchronization will take a BITS input or some other frequency reference. I've used that extensively with SONET gear and the good old Datum OT-21. I never used the 7200 MIX, so I'm not sure if it could take an external reference or just recover clock from a DS1 port. Seems like a good use for an AUX port if you don't need a modem or reverse telnet! Scott Scott McGrath wrote: Actually you might get pretty good results if you have a 6509 as any activity on the serial port triggers a CPU interrupt which is why on a overloaded 6509 the first thing to try is no logging console to get the cpu down from 100% - usually in the context of DDoS and the control plane is slammed as the EOBC is only a 1 megabit channel even on the 3BXL's.This is one of the advantages of the annual trek out to Bldg 14 in San Jose - one gets to meet the guys who developed the code for the routers. This has more than passing interest for me as one could take a NovaTel GPSCard which has a 1PPS output and runs on a single 12-36V supply and has a dedicated 1PPS output at serial levels and install one at each router location.Still have not disassembled the 2501 and 2611 to see which cheapo TCXO Cisco has installed. What do you have available at your shop - we are running SUP720-3BXL's running 12.2 SXF On Sun, Oct 5, 2008 at 1:00 AM, Dave hartzell [EMAIL PROTECTED] wrote: Looks like Trimble and Cisco got together on a PPS implementation for the 7200, starting with 12.0T trainwreck: http://www.cisco.com/en/US/docs/ios/12_1t/12_1t1/feature/guide/dtrimble.html Since I don't have any 7200s any longer (thank goodness), I checked and it seems that the 6500s support this as well on the console serial port: 6509-rtr(config-line)#ntp ? pps-discipline Use PPS pulse to discipline system clock refclockNTP Reference Clock and 6509-rtr(config-line)#ntp refclock ? telecom-solutions Telecom Solutions GPS trimbleTrimble Navigation TSIP Protocol It looks interesting, and if the code is just looking for a PPS transition on the CTS or RI, you might be in luck with any external PPS... BUT be forewarned, IOS is a cooperative multitasking operating system (at least prior to the new modular stuff), so your accuracy is going to vary depending on loads, processes, etc. I wouldn't count on this being to spectacular... probably no better than an external NTP source. And of course, you can always call the TAC for more assistance! ;-) 73, Dave AF6KD On Fri, Oct 3, 2008 at 2:39 PM, Robert Vassar [EMAIL PROTECTED] wrote: I've been fiddling around with an old Cisco router here at the house to brush up. We have an IPv6 project going at work, and our WAN provider provides no native transit, so I'm looking at doing some tunneling. Anyhow... I discovered IOS 12.1 and above have native NTP capability. I don't have the exhaustive IOS command reference, and I suspect it's a limited NTP implementation. I'm wondering if it's possible to tie a GPS unit to a router serial port and gain a stratum 0 refclock. Any Cisco guru's on the list? :-) Cheers, Rob ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS, NTP, and Cisco routers...
What do you need to know about NTP on IOS? - I've been working with Cisco gear longer than I care to admit and have a bunch of CC* certifications but that's not relevant here Generally IOS devices actually speak SNTP - Not sure whether they can use an external reference clock I don't think so BUT it might be possible to replace the cheap TCXO universally used by cisco with a buffer circuit and derive your clock from there and configure the device as a ntp server.Let me peek inside one of the routers hanging around here and I'll see what can be done - Scott On Fri, Oct 3, 2008 at 5:39 PM, Robert Vassar [EMAIL PROTECTED] wrote: I've been fiddling around with an old Cisco router here at the house to brush up. We have an IPv6 project going at work, and our WAN provider provides no native transit, so I'm looking at doing some tunneling. Anyhow... I discovered IOS 12.1 and above have native NTP capability. I don't have the exhaustive IOS command reference, and I suspect it's a limited NTP implementation. I'm wondering if it's possible to tie a GPS unit to a router serial port and gain a stratum 0 refclock. Any Cisco guru's on the list? :-) Cheers, Rob ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS, NTP, and Cisco routers...
Looks like Trimble and Cisco got together on a PPS implementation for the 7200, starting with 12.0T trainwreck: http://www.cisco.com/en/US/docs/ios/12_1t/12_1t1/feature/guide/dtrimble.html Since I don't have any 7200s any longer (thank goodness), I checked and it seems that the 6500s support this as well on the console serial port: 6509-rtr(config-line)#ntp ? pps-discipline Use PPS pulse to discipline system clock refclockNTP Reference Clock and 6509-rtr(config-line)#ntp refclock ? telecom-solutions Telecom Solutions GPS trimbleTrimble Navigation TSIP Protocol It looks interesting, and if the code is just looking for a PPS transition on the CTS or RI, you might be in luck with any external PPS... BUT be forewarned, IOS is a cooperative multitasking operating system (at least prior to the new modular stuff), so your accuracy is going to vary depending on loads, processes, etc. I wouldn't count on this being to spectacular... probably no better than an external NTP source. And of course, you can always call the TAC for more assistance! ;-) 73, Dave AF6KD On Fri, Oct 3, 2008 at 2:39 PM, Robert Vassar [EMAIL PROTECTED] wrote: I've been fiddling around with an old Cisco router here at the house to brush up. We have an IPv6 project going at work, and our WAN provider provides no native transit, so I'm looking at doing some tunneling. Anyhow... I discovered IOS 12.1 and above have native NTP capability. I don't have the exhaustive IOS command reference, and I suspect it's a limited NTP implementation. I'm wondering if it's possible to tie a GPS unit to a router serial port and gain a stratum 0 refclock. Any Cisco guru's on the list? :-) Cheers, Rob ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] GPS, NTP, and Cisco routers...
On Fri, Oct 03, 2008 at 06:46:17PM -0400, [EMAIL PROTECTED] wrote:
From: Robert Vassar [EMAIL PROTECTED]
Subject: [time-nuts] GPS, NTP, and Cisco routers...
I've been fiddling around with an old Cisco router here at the house
to brush up. We have an IPv6 project going at work, and our WAN
provider provides no native transit, so I'm looking at doing some
tunneling. Anyhow... I discovered IOS 12.1 and above have native NTP
capability. I don't have the exhaustive IOS command reference, and I
suspect it's a limited NTP implementation. I'm wondering if it's
possible to tie a GPS unit to a router serial port and gain a stratum
0 refclock.
Any Cisco guru's on the list? :-)
Cisco routers have a fairly basic NTP capability. No chance right now of
using the serial port to speak to a GPS or synced clock on 90% of the gear.
I can't say for certain on some of the really high-end stuff but I kinda
doubt it.
Its really only intended for redistribution, heck, you can even *set* what
Stratum you claim to be ( by default I think Cisco uses 8 ). The only
extra features they support is they will do ntp/multicast which is nice
from a client config point of view for us at least.
I'm using a pair of Endrun CDMA based ntp servers because they will work
inside a colo without external antennas, they sync our Cisco cores which
multicast out to the clients. We're within a few milliseconds which is
close enough. For redistribution to customers we sync a bunch of unix ntp
servers directly off the CDMA servers so our customers get Stratum 2. I
hope to be adding a third Endrun box to the mix shortly where I can put up
an external GPS antenna...
--
- Tom Arnold - ...is it a virus, a drug, or a religion?
- Sysabend Caretaker -Juanita Shrugs. What's the difference?
-- Neal Stephenson, Snow Crash
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