Bill Unruh schrieb: > On Fri, 30 Oct 2009, walter harms wrote: > >> Hi list, >> the question is a bit of topic, but >> has someone a dial-in server with ntpd running ? >> we have noticed that 'ntpd 4.2.4p6' seems >> to have problems accepting connections from ppp0. >> > > Lets understand your problem a bit better. You have a machine which is > connected to the net via ppp. That machine is listed as an ntp server on > another machine. That other machine is having trouble syncing to this > machine. the box in question has 2 interfaces: 1.permanent eth0 2. demand ppp0 the box is running the ntpd and it works. now a 2. box is connecting via modem (ppp0) and tries to get time vi ntp. This fails often. > What evidence do you have that the the problem is "accepting connections"? > Do you have a tcpdump which shows that the ntp packets are being > dropped by no, i took a look with "netstat -l" and you can see the daemon listen to ip:ntp > the server (ie not being processed ) (up the poll interval to 4 on the > outside > machine so you can see the packets over a reasonable period of time) > > >> i "fixed" the problem with a kill -1 in ip-up. > > I have no idea how a kill -1 ( of what?) would fix anything. As James pointed out ntpd is reading the interface list at start (i did not read the code so do not take it literal). so when ip-up is called by pppd it does a "kill -HUP $(pidof ntpd)". This causes ntpd to reread the interfaces (confirmed with netstat -l) and it replys propperly. It seems that ntpd is scanning the interfaces from time to time because it notice sometimes that ppp0 is there and stays for a while. That means if someone is testing and it works, it may work again if the redail is soon enought (interface not droped yet) but if it takes a bit longer (e.g. you have a phonecall) it does not work anymore. hope that helps, wh -- To unsubscribe from this list: send the line "unsubscribe linux-ppp" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
