On 2014-09-11, Rob <[email protected]> wrote: > Martin Burnicki <[email protected]> wrote: >> This is also what Rob has mentioned in another post of this thread, and >> I agree with Rob that a one approach could be to specify (and configure >> for ntpd) the systematic error due to asymmetry of your internet connection. >> >> However, this can also be pretty tricky if you have several NTP nodes on >> your home network, if all nodes and the inet router are connected to the >> same switch. >> >> For different nodes on you home net there is no asymmetry (thus no time >> error), but for each of them who contacts also an external server there >> is. And often a specific machine contacts the other internal devices as >> well as the external ones via the same own LAN interface. >> >> So for your internal operation this means: >> >> - If you specify a fudge time for a specific interface this may be OK >> for external servers but yield an error for internal servers, i.e. >> exactly the other way round as without compensation. >> >> - You had indeed to specify a fudge time for servers of which you know >> they are outside on the internet, e.g. other pool servers >> >> >> On the other hand, if your local NTP server shall be accessible both for >> external pool clients, and local clients, how should you know where a >> specific request comes from? Based on the IP address? Only if the local >> network and the internet interface are connected via different interfaces? >> >> So even though it would be good to be able to specify some compensation >> values, there should be different ways to do it, and putting all >> together in a way that there is no error is tricky. > > Well, in my own system I have a different IP address for the internet > than I have for my local network. In the bug report I asked for a > fudge time1 that could be specified per local IP addres. This would > work OK in my case. When you use the same address on a LAN and on > internet it is more difficult. I guess this only happens in cases > where there is a NAT router that translates requests from internet to > a local address. Not a configuration I would recommend when being > in the pool anyway.
Nope. You could have a local network in which each computer has its own public IP addess, but the connection to that subnetwork is assymetric. I doubt that NAT would add much assymetry. An adsl connection might well since they advertise very different rates up from down. _______________________________________________ questions mailing list [email protected] http://lists.ntp.org/listinfo/questions
