[Dnsmasq-discuss] Incorrect broadcast address given

[OB Lutz]

Sorry, wasnt that clear in my explanation
This happens when the address range is at the end of a traditional
class C subnet (192.168.2.0/24). So the router's ip range is
x.x.x.224-255, with .225 being br-lan, .255 being its broadcast
address,and attempting to give dhcp'd ips from .230 through .254.
Using an address range anywehre else, such as the range you have,
works correctly.

>From the router:
# ifconfig br-lan
br-lan    Link encap:Ethernet  HWaddr 00:D0:12:09:91:52
          inet addr:192.168.8.225  Bcast:192.168.8.255  Mask:255.255.255.224

>From my laptop, after getting an ip via dhcp
$ ifconfig eth0
eth0      Link encap:Ethernet  HWaddr 00:1D:09:C2:74:BC
          inet addr:192.168.8.253  Bcast:192.168.8.226  Mask:255.255.255.224

On Tue, Oct 7, 2008 at 9:56 AM, B. Cook <bcook at poughkeepsieschools.org> wrote:
>
> On Oct 6, 2008, at 11:17 AM, OB Lutz wrote:
>
>> Hi
>> I'm running dnsmasq 2.41 on openwrt kamikaze. My network has various
>> routers with blocks of 32 addresses hanging off of them. On every 8th
>> router, the relevant line from my dnsmasq.conf is :
>>
>> dhcp-range=vlan0,192.168.8.230,192.168.8.254,255.255.255.224,48h
>>
>> This should yield a broadcast address of 192.168.8.255. However, when
>> obtaining an IP address from the router, I am given a broadcast IP of
>> 192.168.8.226, which happens to be the IP of a wireless interface on
>> the router. Changing the configuration to specify the broadcast
>> address manually everything is fine. Other IP ranges yield the proper
>> broadcast, but every router whose addresses are at the end of the
>> class C subnet give this incorrect broadcast address.
>>
>> _______________________________________________dnsmasq-discuss at lists.thekelleys.org.uk
>> Dnsmasq-discuss mailing list
>> Dnsmasq-discuss at lists.thekelleys.org.uk
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>
> Hmm,
>
>  ipcalc -n 192.168.8.230/27
> Address:   192.168.8.230        11000000.10101000.00001000.111 00110
> Netmask:   255.255.255.224 = 27 11111111.11111111.11111111.111 00000
> Wildcard:  0.0.0.31             00000000.00000000.00000000.000 11111
> =>
> Network:   192.168.8.224/27     11000000.10101000.00001000.111 00000
> HostMin:   192.168.8.225        11000000.10101000.00001000.111 00001
> HostMax:   192.168.8.254        11000000.10101000.00001000.111 11110
> Broadcast: 192.168.8.255        11000000.10101000.00001000.111 11111
> Hosts/Net: 30                    Class C, Private Internet
>
> Looks like what you are asking for is correct.
>
> I am using things like this without any problems..
>
> dhcp-range=172.16.64.11,172.16.64.25,255.255.255.224,8h
>
> dnsmasq --version
> Dnsmasq version 2.45  Copyright (C) 2000-2008 Simon Kelley
> Compile time options no-IPv6 GNU-getopt BSD-bridge no-ISC-leasefile no-DBus
> no-I18N TFTP
>
> I am not sure what you mean by "every router whose addresses are at the end
> of the class C subnet give this incorrect broadcast address"..
>
> What do you define for vlan0 what does that look like?
>
>
>
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>