H3C S5600 series Operation Manual

Also see for H3C S5600 Series: Configuration Operation manual Operation manual Operation manual Operation manual

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H3C S5600 series Operation Manual Manual pdf 3 page image

Operation Manual – NTPH3C S5600 Series Ethernet Switches-Release 1510 Chapter 1 NTP Configuration1-2Note:z The accuracy of a clock is determined by its stratum, which ranges from 1 to 16. Thestratum of the reference clock ranges from 1 to 15. The accuracy descends with theincreasing of stratum number. The clocks with the stratum of 16 are inunsynchronized state and cannot serve as reference clocks.z The local clock of an S5600 series switch cannot operate as a reference clock. Andan S5600 series switch can serve as a time server only when it is synchronized.1.1.2 Working Principle of NTPThe 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, andthey need to synchronize the clocks of each other through NTP. For ease ofunderstanding, suppose that:z Before the system clocks of LS_A and LS_B are synchronized, the clock of LS_Ais 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 besynchronized to that of LS_B.z It takes one second for a packet sent by one switch to reach the other.Netw orkNetw orkNTP Packet10:00:00amNetw orkNetw ork11:00:01am10:00:00am 11:00:01am 11:00:02am10:00:00amNTP Packet received at 10:00:031.2.3.4.LS_ALS_ALS_ALS_ALSLS_B_BLSLS_B_BNTP PacketNTP PacketNetw orkNetw orkNTP Packet10:00:00 amNetw orkNetw ork11:00:01 am10:00:00 am 11:00:01 am 11:00:02 am10:00:00 amNTP Packet received at 10:00:03 am1.2.3.4.LS_ALS_ALS_ALS_ALSLS_B_BLSLS_B_BNTP PacketNTP PacketNetw orkNetw orkNTP Packet10:00:00amNetw orkNetw ork11:00:01am10:00:00am 11:00:01am 11:00:02am10:00:00amNTP Packet received at 10:00:031.2.3.4.LS_ALS_ALS_ALS_ALSLS_B_BLSLS_B_BNTP PacketNTP PacketNetw orkNetw orkNTP Packet 10:00:00 amNetw orkNetw ork11:00:01 am10:00:00 am 11:00:01 am 11:00:02 am10:00:00 amNTP Packet received at 10:00:03 am1.2.3.4.LS_ALS_ALS_ALS_ALS_BLS_BLS_LS_BBNTP PacketNTP PacketNetw orkNetw orkNTP Packet10:00:00amNetw orkNetw ork11:00:01am10:00:00am 11:00:01am 11:00:02am10:00:00amNTP Packet received at 10:00:031.2.3.4.LS_ALS_ALS_ALS_ALSLS_B_BLSLS_B_BNTP PacketNTP PacketNetw orkNetw orkNTP Packet10:00:00 amNetw orkNetw ork11:00:01 am10:00:00 am 11:00:01 am 11:00:02 am10:00:00 amNTP Packet received at 10:00:03 am1.2.3.4.LS_ALS_ALS_ALS_ALSLS_B_BLSLS_B_BNTP PacketNTP PacketNetw orkNetw orkNTP Packet10:00:00amNetw orkNetw ork11:00:01am10:00:00am 11:00:01am 11:00:02am10:00:00amNTP Packet received at 10:00:031.2.3.4.LS_ALS_ALS_ALS_ALSLS_B_BLSLS_B_BNTP PacketNTP PacketNetw orkNetw orkNTP Packet 10:00:00 amNetw orkNetw ork11:00:01 am10:00:00 am 11:00:01 am 11:00:02 am10:00:00 amNTP Packet received at 10:00:03 am1.2.3.4.LS_ALS_ALS_ALS_ALS_BLS_BLS_LS_BBNTP PacketNTP PacketFigure 1-1 Working principle of NTP