H3C Technologies H3C WX3000E Series Wireless Switches User Manual
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NOTE:
All NTP messages mentioned in this document refer to NTP clock synchronization messages.
A clock synchronization message is encapsulated in a UDP message, in the format shown in
Figure 6 Clock synchronization message format
Main fields are described as follows:
•
LI (Leap Indicator)—A 2-bit leap indicator. If set to 11, it warns of an alarm condition (clock
unsynchronized). If set to any other value, it is not to be processed by NTP.
•
VN (Version Number)—A 3-bit version number that indicates the version of NTP. The latest version
is version 4.
•
Mode—A 3-bit code that indicates the work mode of NTP. This field can be set to these values:
{
0—Reserved
{
1—Symmetric active
{
2—Symmetric passive
{
3—Client
{
4—Server
{
5—Broadcast or multicast
{
6—NTP control message
{
7—Reserved for private use
•
Stratum—An 8-bit integer that indicates the stratum level of the local clock, taking the value of 1 to
16. Clock precision decreases from stratum 1 through stratum 16. A stratum 1 clock has the highest
precision, and a stratum 16 clock is not synchronized.
•
Poll—An 8-bit signed integer that indicates the maximum interval between successive messages,
which is called the poll interval.