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NTP not working??

I'm having a problem getting NTP packets to pass through my firewall.  My NTP client (MRTech ClockAlign) has three options for protocol to use. . .SNMP, which works fine, and standard NTP via UDP or TCP, neither of which does.  The downer on this is that SNMP NTP requests have the least info of all types, I'm told.

I have defined NTP on my definitions as dest. port 37 UDP/TCP, send.port 1024:65535.  I have then created a rule in the packet filters that says "Any" NTP from "Any" allow.

Nevertheless, when I try to sync my clock using MRTech on TCP or UDP the packet filter shows the following:

11:51:30 192.168.0.33 2008  ->  192.5.41.40 37 TCP SYN
11:51:30 192.168.0.33 2009  ->  192.5.41.40 37 TCP SYN
11:51:34 192.168.0.33 2009  ->  192.5.41.40 37 TCP SYN
11:51:34 192.168.0.33 2010  ->  192.5.41.40 37 TCP SYN

and with UDP:

11:54:02 192.168.0.33 2074  ->  192.5.41.40 37 UDP
11:54:06 192.168.0.33 2076  ->  192.5.41.40 37 UDP
11:54:10 192.168.0.33 2079  ->  192.5.41.40 37 UDP
11:54:14 192.168.0.33 2081  ->  192.5.41.40 37 UDP
11:54:18 192.168.0.33 2083  ->  192.5.41.40 37 UDP

Switch it to SNMP and it's fat & happy.

Any clues?

Thanks

Dan

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0 kr8 over 22 years ago

Code:


Hi,

Not sure why this thread has lasted this long without a resolution, but unless you have a Packet Filter
rule that is clobering your NTP rule, this is what I have in my configuration, and I have no issues.

I access any NTP server from my LAN to the Internet using the following rules.


Network / NAT/Masquerading
	Intranet_to_Internet	 	Intranet -> All / All	 	MASQ__eth2	 	None


Packet Filter / Rules
	Intranet  	{ ntp }  	Any  	Allow


...and the details to define the objects:


Definitions / Networks
	Intranet  	192.168.2.0  	255.255.255.0


Definitions / Services
	NTP  		udp  	123  		123  	 	
	NTP-Async 	udp 	1024:65535 	123


Definitions / Service Groups
	ntp
		NTP
		NTP-Async


Using the above will certainly give you access to any NTP server from your Intranet to the Internet.

Not sure if this is any help to you but I'm sure you can bend the "rules" to do what you need. :-)


Regards
kr8

Reply

0 kr8 over 22 years ago

Code:


Hi,

Not sure why this thread has lasted this long without a resolution, but unless you have a Packet Filter
rule that is clobering your NTP rule, this is what I have in my configuration, and I have no issues.

I access any NTP server from my LAN to the Internet using the following rules.


Network / NAT/Masquerading
	Intranet_to_Internet	 	Intranet -> All / All	 	MASQ__eth2	 	None


Packet Filter / Rules
	Intranet  	{ ntp }  	Any  	Allow


...and the details to define the objects:


Definitions / Networks
	Intranet  	192.168.2.0  	255.255.255.0


Definitions / Services
	NTP  		udp  	123  		123  	 	
	NTP-Async 	udp 	1024:65535 	123


Definitions / Service Groups
	ntp
		NTP
		NTP-Async


Using the above will certainly give you access to any NTP server from your Intranet to the Internet.

Not sure if this is any help to you but I'm sure you can bend the "rules" to do what you need. :-)


Regards
kr8

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