3500yl SNTP Question

[jaredo_1]

I have 2 3500yl switches configured as my core (VRRP/MSTP/VLANs).

VLAN1 is my management VLAN while my SNTP servers (Windows 2008) reside on VLAN10.

When I configure SNTP to the servers on vlan10, I do not get time updates. Everything else that runs from other vlans communicates fine, and the servers ntp servers respond accordingly. Additionally, I tried to setup remote syslog logging to a server on VLAN10, and the switches are not successfully sending syslog messages.

I can ping everything fine on any vlan from the switches, everything is running as normal otherwise.

timesync sntp
sntp unicast
sntp 30
sntp server priority 1 10.10.10.3 4
sntp server priority 2 10.10.10.4 4

Looking at local logs:
I 11/05/10 09:39:05 02631 SNTP: server not found at 10.10.10.3.
I 11/05/10 09:39:14 02631 SNTP: server not found at 10.10.10.4.
I 11/05/10 09:39:14 00414 SNTP: all configured servers failed

sh sntp reports:
SNTP Configuration

SNTP Authentication : Disabled
Time Sync Mode: Sntp
SNTP Mode : Unicast
Poll Interval (sec) [720] : 30
Source IP Selection: Outgoing Interface


Priority SNTP Server Address Version Key-id
-------- --------------------------------------- ------- ----------
1 10.10.10.3 4 0
2 10.10.10.4 4 0




Any ideas?

[Jeff Carrell]

Have you tried timep instead of sntp?

Seems like I had this issue in my lab with W2K8, but I'm not there at the moment to verify.

hth...Jeff

[jaredo_1]

Yea nothing from timep either, also tried several ntp versions (3/4).

Also tried ip source-interface sntp vlan 10

[jaredo_1]

There is a firmware update I'll try this weekend but don't see anything in the change log regarding ntp.

Currently running K.14.47

[jaredo_1]

CORE1(config)# sh sntp

SNTP Configuration

SNTP Authentication : Disabled
Time Sync Mode: Sntp
SNTP Mode : Unicast
Poll Interval (sec) [720] : 30
Source IP Selection: 10.10.10.1


Priority SNTP Server Address Version Key-id
-------- --------------------------------------- ------- ----------
1 10.10.10.3 3 0
2 10.10.10.4 4 0

CORE1(config)# sh sntp statistics
SNTP Statistics

Received Packets : 0
Sent Packets : 86467
Dropped Packets : 0

SNTP Server Address Auth Failed Pkts
--------------------------------------- ----------------
10.10.10.3 0
10.10.10.4 0

[jaredo_1]

Was able to point it to an external ntp server with ip source sntp vlan 1, guess I'll just do that for now.

[macrocozm]

Can you ping between the switch <-> servers?

[jaredo_1]

"I can ping everything fine on any vlan from the switches, everything is running as normal otherwise."

Same from the servers.

[Glen Van Lehn]

jaredo, if routing works between v1 & v10, and your connection to the external ntp site also works, how does access-control work on the windows servers?

On my linux ntp servers, I need to add some config lines as to which ip ranges are allowed to query.

What are results of "#show sntp statistics" on the 3500?

[Olaf Borowski]

According to your statistics, the switch is querying the SNTP server but never gets a response. Check the firewall rules of the Win2008 server. Make sure UDP port 123 is allowed.
http://bchavez.bitarmory.com/archive/2009/12/21/how-to-setup-a-windows-2008-r2-sntp-ntp-server.aspx

ICMP (ping) is probably allowed so this is not a good test. Install a tool like wireshark are see if the server actually responds (assuming there is not other firewall in play).