Shape NTP traffic

[lars_4]

Hi,

I have a stratum 1 NTP server on a 60/60mbit fiber connection, i also use the same line for private use.
The problem is that when i use a lot of bandwidth privately the external NTP packets get delayed a little bit which shows in the external monitoring.
Is there a way i can make the NTP packets have the highest priority?

Have one WAN and one LAN interface.
I am absolutely new to traffic shaping and the wizards are not that easy for me.
Maybe someone can help me through it for the first time?

[dusan]

The simplest way would be to run NTP in a dedicate queue.

For example, I put NTP in qGames for my stratum 2 NTP server. The Internet link is symmetrical 30/30 mbps. I use for years HFSC, with 7 queues created by the wizard. My bandwidth allocation is qDefault = qHigh = qGames = qVoIP = 20%, qLow = 10%, qACK = 8%, qP2P = 2%.

[lars_4]

Sound very interesting.
How does pfsense see the difference between NTP and other traffic?

What do i need to fill in the wizard to have a simular setup?

[dusan]

@lars_4:

Sound very interesting.
How does pfsense see the difference between NTP and other traffic?

NTP's destination port is 123 UDP and (rarely) TCP.

@lars_4:

What do i need to fill in the wizard to have a simular setup?

Nothing special, just accept the default to finish the wizard then edit the queues and firewall rules using Firewall -> Traffic Shaper -> By Interface and Firewall -> Rules -> Floating (in v.2.0).

[dhatz]

@dusan:

NTP's destination port is 123 UDP and (rarely) TCP.

Does NTP ever use TCP/123 ?

It doesn't according to the NTP folks:

"Note that NTP does not use TCP in any form. Also note that NTP requires port 123 for both source and destination ports." – http://www.eecis.udel.edu/~mills/ntp/html/debug.html