No NTP service available on Cisco 1600 and 1700 routers

graeme.white · ‎01-05-2007

Hello

I have 25 Cisco routers in our company

the two 2600 routers support NTP no problem.

The rest of our 1600 and 1700 do not seem to support NTP.

If i go into privileged mode and configure terminal and do a show command, NTP is not displayed

If I type #ntp ?

i get an unrecognized command reply

All our routers have IOS 12.x

As far as I know from IOS 9.21 and up NTP is supported?

We are using EIGRP, nothing complicated.

What am I missing?

rkuiters · ‎01-05-2007

Hi,

use sntp

Cheers,

Rob

Richard Burts · ‎01-05-2007

Graeme

I wonder if it is a feature set issue since I know that NTP is supported in at least some IOS for those routers. I have configured NTP on lots of 1700 routers (not so many 1600) and it is supported and works just fine. Can you post the output of show version from one of the routers where NTP is not present? That should give information about version and feature set.

HTH

Rick

HTH

Rick

eofelt · ‎01-05-2007

In support what Rob wrote...

Some low-end routers, such as the 1600 and 1700 series, don't support the full NTP protocol. They support only a stripped-down version called SNTP. SNTP is a client-only version of NTP and can be configured with the sntp server command.

Btw, relating to NTP, be aware of security issues implementing NTP(ACLs should restrict what servers the router synchronizes to and systems the router will synchronize. etc).

HTH, please rate if so.

Richard Burts · ‎01-05-2007

I take exception to the statement that 1700 does not support NTP. I have configured the regular NTP protocol (not SNTP) on many 1700s and it is supported. It may be a feature set issue (supported in some feature sets but not in others) but it is not a model or platform issue.

HTH

Rick

HTH

Rick

rkuiters · ‎01-05-2007

We have some 1700 routers inour network and not one of them is configurable with ntp, only with sntp.So if you can't use ntp use sntp instead.

Cheers,

Rob

eofelt · ‎01-05-2007

All,

I accept Rick's exception and recant my statement about NTP on 1700.

I'm sure it is IOS dependent.

Richard Burts · ‎01-05-2007

And I accept Rob's statement (and yours) that it may not be supported in some versions (feature sets). And if NTP is not supported in what you are running (and if upgrading to one that does support NTP is not feasible) then running SNTP is a good alternative.

HTH

Rick

HTH

Rick

andrew.burns · ‎01-05-2007

Hi,

Traditionally NTP used to be only supported in "IP PLUS" images for 1600/1700 routers, but Cisco moved it to IP only for a while then moved it back to plus images, hence why you sometimes find it and sometimes don't even though you appear to be running the same feature set. You can get NTP for these routers - you just need to find the right IOS.

If you want to know exactly what image supports it use the feature navigator:

http://tools.cisco.com/ITDIT/CFN/jsp/index.jsp

HTH

Andrew.

graeme.white · ‎01-05-2007

Hi guys

Thank you so much for all the info.

You have really taught me a lot

here is a show version dump

Cisco Internetwork Operating System Software

IOS (tm) C1700 Software (C1700-Y-M), Version 12.2(4)T1, RELEASE SOFTWARE (fc1)

TAC Support: http://www.cisco.com/tac

Compiled Thu 25-Oct-01 18:52 by ccai

Image text-base: 0x800080E0, data-base: 0x80738BD8

ROM: System Bootstrap, Version 12.0(3)T, RELEASE SOFTWARE (fc1)

ZA-RT-DB001 uptime is 10 hours, 16 minutes

System returned to ROM by power-on

System image file is "flash:c1700-y-mz.122-4.T1.bin"

cisco 1720 (MPC860) processor (revision 0x601) with 24576K/8192K bytes of memory

.

Processor board ID JAD0601025K (3189709239), with hardware revision 0000

M860 processor: part number 0, mask 32

Bridging software.

X.25 software, Version 3.0.0.

1 FastEthernet/IEEE 802.3 interface(s)

2 Serial(sync/async) network interface(s)

32K bytes of non-volatile configuration memory.

8192K bytes of processor board System flash (Read/Write)

Configuration register is 0x2102

graeme.white · ‎01-05-2007

Andrew,

The link to the tool has helped me.

You are all right, NTP is not a feature of my IOS :(

I am trying to use SNTP

I punch in:

sntp server x.x.x.x (x.x.x.x = NTP server on our network)

It is not automatically updating the date and time.

Am I missing something?

graeme.white · ‎01-05-2007

i have tried the sntp route, here is a sntp status dump

Router#sh sntp

SNTP server Stratum Version Last Receive

x.x.x.x 16 1 never

Broadcast client mode is enabled.

rkuiters · ‎01-05-2007

I don't know how bussy your router is but with a low cpu load you could consider a debug sntp packets and see if there is communication between the client and server.

I'd a debug on one of our routers:

SNTP server Stratum Version Last Receive

ntp.server.1.4 3 1 00:00:38 Synced

ntp.server.1.2 3 1 00:00:39

ntp.server.1.1 2 1 4w3d

ntp.server.1.3 2 1 4w3d

gv-2596ec-1#debug sntp packets

SNTP packets debugging is on

gv-2596ec-1#term mon

gv-2596ec-1#

Jan 5 20:35:55: Sending SNTP packet to ntp.server.1.1

Jan 5 20:35:55: xmt C949352B.8DC001F2 (21:35:55.553 CEST Fri Jan 5 2007)

Jan 5 20:35:56: Sending SNTP packet to ntp.server.1.2

Jan 5 20:35:56: xmt C949352C.61B71E4C (21:35:56.381 CEST Fri Jan 5 2007)

Jan 5 20:35:56: Received SNTP packet from ntp.server.1.2, length 48

Jan 5 20:35:56: leap 0, mode 4, version 1, stratum 3, ppoll 16

Jan 5 20:35:56: rtdel 00000312, rtdsp 00000576, refid AC10020A (172.16.2.10)

Jan 5 20:35:56: ref C949335D.85EB4000 (21:28:13.523 CEST Fri Jan 5 2007)

Jan 5 20:35:56: org C949352C.61B71E4C (21:35:56.381 CEST Fri Jan 5 2007)

Jan 5 20:35:56: rec C949352C.668DF000 (21:35:56.400 CEST Fri Jan 5 2007)

Jan 5 20:35:56: xmt C949352C.6696B000 (21:35:56.400 CEST Fri Jan 5 2007)

Jan 5 20:35:56: inp C949352C.6B21BBBF (21:35:56.418 CEST Fri Jan 5 2007)

Jan 5 20:35:56: Sending SNTP packet to ntp.server.1.3

Jan 5 20:35:56: xmt C949352C.FB5168BE (21:35:56.981 CEST Fri Jan 5 2007)

Jan 5 20:35:57: Sending SNTP packet to ntp.server.1.4

Jan 5 20:35:57: xmt C949352D.4404F038 (21:35:57.265 CEST Fri Jan 5 2007)

Jan 5 20:35:57: Received SNTP packet from ntp.server.1.4, length 48

Jan 5 20:35:57: leap 0, mode 4, version 1, stratum 3, ppoll 16

Jan 5 20:35:57: rtdel 0000030B, rtdsp 000001A8, refid AC10020A (172.16.2.10)

Jan 5 20:35:57: ref C949350A.D7251000 (21:35:22.840 CEST Fri Jan 5 2007)

Jan 5 20:35:57: org C949352D.4404F038 (21:35:57.265 CEST Fri Jan 5 2007)

Jan 5 20:35:57: rec C949352D.48E97000 (21:35:57.284 CEST Fri Jan 5 2007)

Jan 5 20:35:57: xmt C949352D.48EF4000 (21:35:57.284 CEST Fri Jan 5 2007)

Jan 5 20:35:57: inp C949352D.4D595C7E (21:35:57.302 CEST Fri Jan 5 2007)

gv-2596ec-1#u all

All possible debugging has been turned off

gv-2596ec-1#

graeme.white · ‎01-07-2007

Hi there

Ran the debug, it just keeps sending but no reply from the NTP server.

I do know it works because our Cisco 2600 receives updates from the x.x.x.x address.

Am I missing something in my config?

This is my config:

sntp server x.x.x.x

sntp broadcast client

end

This is the debug:

Router#show clock

*21:34:36.278 UTC Wed Mar 3 1993

Router#debug sntp pac

Router#debug sntp packets

SNTP packets debugging is on

Router#term mon

Router#