In article <[EMAIL PROTECTED]> Tom Smith <[EMAIL PROTECTED]> writes: >Erik wrote: >> On 15 mrt, 17:21, Tom Smith <[EMAIL PROTECTED]> wrote: >>>> broadcast 145.47.51.127 key 1 >>>> broadcast 145.47.51.255 key 1 >>>> broadcast 145.47.52.127 key 1 >>>> broadcast 145.47.53.127 key 1 >>> That's the right idea, but the second one above already >>> includes the first.
How do you figure that? If (according to latest report) there are two networks a) 145.47.51.0/25 and b) 145.47.51.128/25, the address 145.47.51.255 doesn't "include" 145.47.51.127 in any way. 145.47.51.127 is the broadcast address for a), 145.47.51.255 is the broadcast address for b) - and hosts on network a) will not see 145.47.51.255 as a broadcast address - in fact they will just see it as a random address on a remote network. A broadcast address is either 255.255.255.255 or one where the network part matches exactly and the host part is all-ones. >> there is one network-card in the server that connects to the network >> and has access to the network segments mentioned above >> The IP-data of this server (PC) is (ipconfig-output): >> >> IP-adres . . . . . . . . . . . . . . .: 145.47.54.146 >> Subnetmask . . . . . . . . . . . .: 255.255.255.128 >> Standaardgateway . . . . . . . .: 145.47.54.129 >> >> Does this answer your question? > >Yes. That answers the question. With that configuration, >in order to reach any of the clients, the packets that the >server sends will have to be routed and cannot (usually) be >broadcast. The server can (usually) only broadcast to its >own subnet(s). > >That said, there are, of course, exceptions. I believe >that if the subnets are, in fact, all on the same VLAN, >you may be able to send a broadcast addressed to a >network wider than the subnet defined by the server's >netmask to any other network on the VLAN. In that case, >you could use the single broadcast address 145.47.63.255 >to reach all of your clients. It might work and it might not. No way *that* could possibly work - it's not a broadcast address on any of the relevant networks. *If* the subnets are actually on the same wire, what *might* work is to give the server an address in each network (using "virtual interfaces" or "aliases" depending on the OS flavor), and then specify all the individual broadcast addresses on their own "broadcast" line in ntp.conf. >The second exception is if your routers are configured >route broadcast messages to be beyond the subnet >on which they originate. In that case, you could again >use the single broadcast address 145.47.63.255 or >the 3 individual broadcast addresses (2 through 4 in >your list). Again, it might or might not work in your >existing network configuration. No - "directed broadcast" could work if the routers are so configured (which they typically aren't, but that could perhaps be changed) - but it still requires that ntpd actually sends out packets with each of the per-network broadcast addresses. But here another problem arises - none of the client-network broadcast addresses are broadcast addresses on the server network. I'm not sure what ntpd will do with "broadcast" lines with an address that isn't actually a broadcast address on any directly- connected network - it would "just" need to send the packets out with the given address and let the kernel routing deal with it, but in case it searches for a local interface with the given broadcast address, it won't find one. >What will work, without question, is not using >broadcast in the first place. You will have to work >with the company who supplied your systems to fix >the problem. You should continue this discussion >with them. This is really no longer about NTP. >It is about your network design. Agreed - sorry for pushing the subject further off-topic.:-) --Per Hedeland [EMAIL PROTECTED] _______________________________________________ questions mailing list [email protected] https://lists.ntp.isc.org/mailman/listinfo/questions
