[solved] ntp and firewall

nTia89 · 2011-08-11 20:43:48

hi to everybody,

does ntp require particular iptables rule to work ?

thanks

Last edited by nTia89 (2011-08-12 12:07:26)

jelly · 2011-08-11 21:34:03

Do you mean the server or the service?

ataraxia · 2011-08-11 21:41:35

You don't need any special port opened to just use ntpd to set your clock correctly. The "--state RELATED,ESTABLISHED" rule is enough to allow replies back to you from timeservers.

fukawi2 · 2011-08-11 23:06:47

nTia89 wrote:

does ntp require particular iptables rule to work ?

NTP uses UDP port 123, so that will need to have an open path in both directions between the client and server(s). This can be done either explicitly with --dport and --sport or using connection tracking as ataraxia has pointed out.

nTia89 · 2011-08-12 09:28:43

so, i need, for example:

iptables -A INPUT -i eth0 -m state --state RELATED,ESTABLISHED -j ACCEPT

before start npd ?
and every time i launch it, because iptables reset every reboot, is right ?

Last edited by nTia89 (2011-08-12 09:29:54)

fukawi2 · 2011-08-12 10:56:02

nTia89 wrote:

and every time i launch it, because iptables reset every reboot, is right ?

Not if you save the rules after you set them

/etc/rc.d/iptables save

nTia89 · 2011-08-12 12:07:11

ok

solved

Arch Linux

#1 2011-08-11 20:43:48

[solved] ntp and firewall

#2 2011-08-11 21:34:03

Re: [solved] ntp and firewall

#3 2011-08-11 21:41:35

Re: [solved] ntp and firewall

#4 2011-08-11 23:06:47

Re: [solved] ntp and firewall

#5 2011-08-12 09:28:43

Re: [solved] ntp and firewall

#6 2011-08-12 10:56:02

Re: [solved] ntp and firewall

#7 2011-08-12 12:07:11

Re: [solved] ntp and firewall

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