Hi,

We are having time server running NTPV3 (Server mode), and a client
running NTPV4.
What should be version field in the packet replied from the server ?
Is there any difference in the replies between v3 and v4 NTP servers ?

Md Nazeem wrote:

> Hi,
> 
> We are having time server running NTPV3 (Server mode), and a client
> running NTPV4.
> What should be version field in the packet replied from the server ?
> Is there any difference in the replies between v3 and v4 NTP servers ?
> 

The version field should report the version being used!

The actual network protocol is identical for version 3 and version 4. 
The changes from version 3 to version 4 were algorithmic improvements 
and new features in the reference implementation.

In article <1169555391.897031.218530@h3g2000cwc.googlegroups.com>,
Md Nazeem <charan.madhu@gmail.com> wrote:

> We are having time server running NTPV3 (Server mode), and a client
> running NTPV4.
> What should be version field in the packet replied from the server ?

I seem to remember that the reference implementation of version 3 will
reject up version polls, although it looks as though version 4.2.0
accepts them, although it rejects up version mode 7 management requests.
It would generally be advisable to explicitly specify that version 3
should be used in the server lines for the downversion servers.

Obviously it cannot respond with a version higher than 3, because it 
doesn't know the future.

NTP V3 is obsolete, though.