NTP synchronization

[mirco_ek]

Hi at all, I'm working with switch HP 5120-EI, I have a little problem with NTP protocol.

I have inserted IP address of internet NTP server so that the switch is synchronized whit it.

Now I want to synchronize my other ethernet equipments with this local switch but this equipments seems not

synchronized.

I have captured NTP UDP packet between my equipments and local switch and I saw that the client query of NTP synchronization coming from my equipments to the switch contains a stratum field = 0, The switch not responding to this message so, the equipment semms not synchronizing.

My question is what happen when a HP 5120 switch receive a request of synchronization from a client with the stratum field = 0? 

 thanks

[Vince-Whirlwind]

Correct me if I am wrong, but your 5120 switches are NTP clients, not servers. 

You will need an NTP server to point all your 5120 NTP clients to.

[mirco_ek]

Hi, sorry but I think you are wrong, as a Configuration Guide said at chapter 10 (Network Management and Monitor Configuration), HP5120 can synchrronize other device on the Local Area Network when it is synchrronize with an external NTP server.

As I explain in the post above, the thre HP 5120 of my scenario seems work properly (The first one (A) is synchrronized with externall NTP server, the other two (B,C) are synchrronized whit the first one (A)) but,  other equipment on the LAN  are not sinchronyzed with (A).

With wireshark I found a strange value of stratum field (stratum=0) in the NTP query that this equipments send to the HP5120 (A) to synchrronize with it and seems that HP5120 (A) don't replay to thees messages.

I think that this values should be between 1 to 16 (1=better precision, 2=worse precision, 16=Unsynchrronized).

My question is : can this value be the cause of not synchrronization of this equipments?

Thank you very much for your replay.

[Apachez-]

Sounds like something you should report to HP.

How is your current ntp settings?

Mine are (I dont sync against my 5120EI, only let them sync against NTP-servers to get proper time):

acl number 2000 name v4-DENY-ANY
hardware-count enable
rule 0 deny

acl number 2001 name v4-MGMT-NTP
hardware-count enable
rule 0 deny fragment 
rule 5 permit source 192.36.144.22 0 
rule 10 permit source 192.36.144.23 0 
rule 15 permit source 192.36.133.17 0 
rule 20 permit source 192.36.133.25 0 
rule 25 permit source 192.36.134.17 0 
rule 30 permit source 192.36.134.25 0 
rule 35 deny

acl ipv6 number 2000 name v6-DENY-ANY
hardware-count enable
rule 0 deny

acl ipv6 number 2001 name v6-MGMT-NTP
hardware-count enable
rule 0 deny fragment 
rule 5 deny routing 
rule 10 deny

ntp-service source-interface Vlan-interface100
ntp-service ipv6 source-interface Vlan-interface100
ntp-service access peer 2001 
ntp-service access server 2000 
ntp-service access synchronization 2000 
ntp-service access query 2000 
ntp-service ipv6 access peer 2001 
ntp-service ipv6 access server 2000 
ntp-service ipv6 access synchronization 2000 
ntp-service ipv6 access query 2000 
ntp-service unicast-server 192.36.144.22
ntp-service unicast-server 192.36.144.23
ntp-service unicast-server 192.36.133.17
ntp-service unicast-server 192.36.133.25
ntp-service unicast-server 192.36.134.17
ntp-service unicast-server 192.36.134.25

[Vince-Whirlwind]

Looks like you are right, the manual for the 5120 says (among other things!)

"The local clock of this Switch Series cannot operate as a reference clock. It can serve as an NTP
server only after it is synchronized."

So if you can show in your 5120 logs that it is succeeding at synchronising against an NTP server, show that to HP support and ask them why it's not working.

I seem to recall having problems with NTP in the earlier releases of Comware7, so maybe also check your firmware version.