Huawei Quidway S3100 Series User Manual

Operation Manual – NTP
Quidway S3100 Series Ethernet Switches Chapter 1
NTP Configuration
Huawei Technologies Proprietary
1-2
 Note:
z The accuracy of a clock is determined by its stratum, which ranges from 1 to 16. The
stratum of the reference clock ranges from 1 to 15. The accuracy descends with the
increasing of stratum number. The clocks with the stratum of 16 are in
unsynchronized state and cannot serve as reference clocks.
z The local clock of an S3100 series switch cannot operate as a master clock. And an
S3100 series switch can serve as a time server only when it is synchronized.
1.1.2 Working Principle of NTP
The working principle of NTP is shown in Figure 1-1.
In Figure 1-1, The Ethernet switch A (LS_A) is connected to the Ethernet switch B
(LS_B) through their Ethernet ports. Both of them have system clocks of their own, and
they need to synchronize the clocks of each other through NTP. For ease of
understanding, suppose that:
z Before the system clocks of LS_A and LS_B are synchronized, the clock of LS_A
is set to 10:00:00am, and the clock of LS_B is set to 11:00:00am.
z LS_B serves as the NTP time server, that is, the clock of LS_A will be
synchronized to that of LS_B.
z It takes one second for a packet sent by one switch to reach the other.
Netw ork
Netw ork
NTP Pac ket 10:00:00am
Netw ork
Netw ork
11:00:01am
10:00:00am 11:00:01am 11:00:02am
10:00:00am
NTP Packet received at 10:00:03
1.
2.
3.
4.
LS_A
LS_A
LS_A
LS_A
LS
LS
_B
_B
LS
LS
_B
_B
NT P Pac ket
NT P Pac ket
Netw ork
Netw ork
NTP Pac ket 10:00:00 am
Netw ork
Netw ork
11:00:01 am
10:00:00 am 11:00:01 am 11:00:02 am
10:00:00 am
NTP Packet received at 10:00:03 am
1.
2.
3.
4.
LS_A
LS_A
LS_A
LS_A
LS
LS
_B
_B
LS
LS
_B
_B
NT P Pac ket
NT P Pac ket
Netw ork
Netw ork
NTP Pac ket 10:00:00am
Netw ork
Netw ork
11:00:01am
10:00:00am 11:00:01am 11:00:02am
10:00:00am
NTP Packet received at 10:00:03
1.
2.
3.
4.
LS_A
LS_A
LS_A
LS_A
LS
LS
_B
_B
LS
LS
_B
_B
NT P Pac ket
NT P Pac ket
Netw ork
Netw ork
NT P Pac ket 10:00:00 am
Netw ork
Netw ork
11:00:01 am
10:00:00 am 11:00:01 am 11:00:02 am
10:00:00 am
NTP Packet received at 10:00:03 am
1.
2.
3.
4.
LS_A
LS_A
LS_A
LS_A
LS_
LS_
B
B
LS_
LS_B
B
NTP Packet
NT P Pac ket
Netw ork
Netw ork
NTP Pac ket 10:00:00am
Netw ork
Netw ork
11:00:01am
10:00:00am 11:00:01am 11:00:02am
10:00:00am
NTP Packet received at 10:00:03
1.
2.
3.
4.
LS_A
LS_A
LS_A
LS_A
LS
LS
_B
_B
LS
LS
_B
_B
NT P Pac ket
NT P Pac ket
Netw ork
Netw ork
NTP Pac ket 10:00:00 am
Netw ork
Netw ork
11:00:01 am
10:00:00 am 11:00:01 am 11:00:02 am
10:00:00 am
NTP Packet received at 10:00:03 am
1.
2.
3.
4.
LS_A
LS_A
LS_A
LS_A
LS
LS
_B
_B
LS
LS
_B
_B
NT P Pac ket
NT P Pac ket
Netw ork
Netw ork
NTP Pac ket 10:00:00am
Netw ork
Netw ork
11:00:01am
10:00:00am 11:00:01am 11:00:02am
10:00:00am
NTP Packet received at 10:00:03
1.
2.
3.
4.
LS_A
LS_A
LS_A
LS_A
LS
LS
_B
_B
LS
LS
_B
_B
NT P Pac ket
NT P Pac ket
Netw ork
Netw ork
NT P Pac ket 10:00:00 am
Netw ork
Netw ork
11:00:01 am
10:00:00 am 11:00:01 am 11:00:02 am
10:00:00 am
NTP Packet received at 10:00:03 am
1.
2.
3.
4.
LS_A
LS_A
LS_A
LS_A
LS_
LS_
B
B
LS_
LS_B
B
NTP Packet
NT P Pac ket
Figure 1-1 Working principle of NTP

Huawei Quidway S3100 Series Specifications

General

Brand	Huawei
Model	Quidway S3100 Series
Category	Switch
Language	English