In article <[EMAIL PROTECTED]> Tom Smith <[EMAIL PROTECTED]> writes: >Per Hedeland wrote: >> 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. > >145.47.51.0/25 = *.0-127 > broadcast 145.47.51.127 broadcasts to all of them >145.47.51.128/25 = = *.128-255 > broadcast 145.47.51.255 broadcasts to all of them > >145.47.51.0/24 - *.0-255 > broadcast 145.47.51.255 broadcasts to all of them
Yes of course - but the 2 x /25 and the 1 x /24 are two different cases, and according to the OP /25 was used here. >Whether it would "work", depends on the next answer, which >was: No, regardless of whether the subnets are on the same wire, or whether routers forward directed broadcasts, the hosts on 145.47.51.0/25 will never see 145.47.51.255 as a broadcast address. For route advertisement to remote networks, adjacent subnets can and should be aggregated - i.e. the router that has both 145.47.51.0/25 and 145.47.51.128/25 can advertise 145.47.51.0/24 - but that doesn't change the local broadcast address on those networks, of course. The remaining points seem to result from a similar misconception, so I won't comment further on them. --Per Hedeland [EMAIL PROTECTED] _______________________________________________ questions mailing list [email protected] https://lists.ntp.isc.org/mailman/listinfo/questions
