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From: itba on 31 May 2010 13:29
Hello,
I have a production server running a slackware (
Linux skoll 2.6.28.7-smp #1 SMP Sat Feb 28 12:26:08)
whit dnsmasq (Dnsmasq version 2.47) and 3 vlans, so I have one file per vlan
ir
order to act as a dhcp server in each virtual interface
The reason for having 3 diferents networks is for security, so:
the configs it's as follows

cat /etc/dnsmasq.conf
dhcp-lease-max=5000
log-dhcp
conf-dir=/etc/dnsmasq.d

cat /etc/dnsmasq.d/red_uno
domain-needed
bogus-priv
interface=lo
interface=eth0.100
dhcp-range=red_uno,10.0.100.0,10.0.255.255,12h
domain=itba.edu.ar,10.0.0.0/16
# Opcion 44: Servidores WINS
dhcp-option=net:red_uno,44,10.0.0.66

cat /etc/dnsmasq.d/red_dos
domain-needed
bogus-priv
interface=lo
interface=eth0.200
domain=alu.itba.edu.ar,172.17.0.0/16
dhcp-range=red_dos,172.17.24.0,172.17.25.255,12h
# Opcion 44: Servidores WINS
dhcp-option=net:red_dos,44,172.17.8.16

cat /etc/dnsmasq.d/red_tres
domain-needed
bogus-priv
interface=lo
interface=eth0.300
dhcp-range=red_tres,10.2.1.0,10.2.100.255,12h
domain=lanwifi.itba.edu.ar,10.2.0.0/16

So, the problems become when a host of a network request an ip, and the
service
responds offering 3 diferent ips, one of each network !
for example: the mac-address of client is 00:13:20:da:ab:69 and it's belong to
"/etc/dnsmasq.d/red_dos" so the valid range is
172.17.24.0,172.17.25.255 and look what it happens then:
grep 00:13:20:da:ab:69 /var/log/dnsmasq/dnsmasq.log

May 31 09:09:21 skoll dnsmasq[3379]: DHCPDISCOVER(eth0.100) 169.254.217.131
00:13:20:da:ab:69
May 31 09:09:21 skoll dnsmasq[3379]: DHCPOFFER(eth0.100) 10.0.235.33
00:13:20:da:ab:69
May 31 09:09:24 skoll dnsmasq[3379]: DHCPDISCOVER(eth0.200) 169.254.217.131
00:13:20:da:ab:69
May 31 09:09:24 skoll dnsmasq[3379]: DHCPOFFER(eth0.200) 172.17.25.34
00:13:20:da:ab:69
May 31 09:09:27 skoll dnsmasq[3379]: DHCPDISCOVER(eth0.300) 169.254.217.131
00:13:20:da:ab:69
May 31 09:09:27 skoll dnsmasq[3379]: DHCPOFFER(eth0.300) 10.2.68.33
00:13:20:da:ab:69
May 31 09:09:27 skoll dnsmasq[3379]: DHCPDISCOVER(eth0.100) 169.254.217.131
00:13:20:da:ab:69
May 31 09:09:27 skoll dnsmasq[3379]: DHCPOFFER(eth0.100) 10.0.235.33
00:13:20:da:ab:69
May 31 09:09:27 skoll dnsmasq[3379]: DHCPDISCOVER(eth0.200) 169.254.217.131
00:13:20:da:ab:69
May 31 09:09:27 skoll dnsmasq[3379]: DHCPOFFER(eth0.200) 172.17.25.34
00:13:20:da:ab:69
May 31 09:09:27 skoll dnsmasq[3379]: DHCPDISCOVER(eth0.300) 169.254.217.131
00:13:20:da:ab:69
May 31 09:09:27 skoll dnsmasq[3379]: DHCPOFFER(eth0.300) 10.2.68.33
00:13:20:da:ab:69
May 31 09:09:28 skoll dnsmasq[3379]: DHCPREQUEST(eth0.100) 10.0.235.33
00:13:20:da:ab:69
May 31 09:09:28 skoll dnsmasq[3379]: DHCPACK(eth0.100) 10.0.235.33
00:13:20:da:ab:69 labb14
May 31 09:09:29 skoll dnsmasq[3379]: DHCPREQUEST(eth0.100) 10.0.235.33
00:13:20:da:ab:69
May 31 09:09:29 skoll dnsmasq[3379]: DHCPACK(eth0.100) 10.0.235.33
00:13:20:da:ab:69 labb14
May 31 09:10:37 skoll dnsmasq[3379]: DHCPINFORM(eth0.100) 10.0.235.33
00:13:20:da:ab:69
May 31 09:10:37 skoll dnsmasq[3379]: DHCPACK(eth0.100) 10.0.235.33
00:13:20:da:ab:69 labb14
May 31 09:12:38 skoll dnsmasq[3379]: DHCPREQUEST(eth0.100) 10.0.235.33
00:13:20:da:ab:69
May 31 09:12:38 skoll dnsmasq[3379]: DHCPACK(eth0.100) 10.0.235.33
00:13:20:da:ab:69 labb14
May 31 09:12:38 skoll dnsmasq[3379]: DHCPREQUEST(eth0.200) 10.0.235.33
00:13:20:da:ab:69
May 31 09:12:38 skoll dnsmasq[3379]: DHCPNAK(eth0.200) 10.0.235.33
00:13:20:da:ab:69 wrong network
May 31 09:12:38 skoll dnsmasq[3379]: DHCPREQUEST(eth0.300) 10.0.235.33
00:13:20:da:ab:69
May 31 09:12:38 skoll dnsmasq[3379]: DHCPNAK(eth0.300) 10.0.235.33
00:13:20:da:ab:69 wrong network
May 31 09:12:42 skoll dnsmasq[3379]: DHCPREQUEST(eth0.100) 10.0.235.33
00:13:20:da:ab:69
May 31 09:12:42 skoll dnsmasq[3379]: DHCPACK(eth0.100) 10.0.235.33
00:13:20:da:ab:69 labb14
May 31 09:12:42 skoll dnsmasq[3379]: DHCPREQUEST(eth0.200) 10.0.235.33
00:13:20:da:ab:69
May 31 09:12:42 skoll dnsmasq[3379]: DHCPNAK(eth0.200) 10.0.235.33
00:13:20:da:ab:69 wrong network
May 31 09:12:42 skoll dnsmasq[3379]: DHCPREQUEST(eth0.300) 10.0.235.33
00:13:20:da:ab:69
May 31 09:12:42 skoll dnsmasq[3379]: DHCPNAK(eth0.300) 10.0.235.33
00:13:20:da:ab:69 wrong network
May 31 09:16:25 skoll dnsmasq[3379]: DHCPINFORM(eth0.100) 10.0.235.33
00:13:20:da:ab:69
May 31 09:16:25 skoll dnsmasq[3379]: DHCPACK(eth0.100) 10.0.235.33
00:13:20:da:ab:69 labb14
May 31 09:16:25 skoll dnsmasq[3379]: DHCPINFORM(eth0.100) 10.0.235.33
00:13:20:da:ab:69
May 31 09:16:25 skoll dnsmasq[3379]: DHCPACK(eth0.100) 10.0.235.33
00:13:20:da:ab:69 labb14
May 31 11:50:35 skoll dnsmasq[20676]: DHCPREQUEST(eth0.100) 10.0.235.33
00:13:20:da:ab:69
May 31 11:50:35 skoll dnsmasq[20676]: DHCPACK(eth0.100) 10.0.235.33
00:13:20:da:ab:69 labb14
May 31 11:50:36 skoll dnsmasq[20676]: DHCPREQUEST(eth0.200) 10.0.235.33
00:13:20:da:ab:69
May 31 11:50:36 skoll dnsmasq[20676]: DHCPNAK(eth0.200) 10.0.235.33
00:13:20:da:ab:69 wrong network
May 31 11:50:36 skoll dnsmasq[20676]: DHCPREQUEST(eth0.300) 10.0.235.33
00:13:20:da:ab:69
May 31 11:50:36 skoll dnsmasq[20676]: DHCPNAK(eth0.300) 10.0.235.33
00:13:20:da:ab:69 wrong network


What is wrong here ?
From: Tauno Voipio on 1 Jun 2010 01:34
On 31.5.10 8:29 , itba wrote:
> Hello,
> I have a production server running a slackware (
> Linux skoll 2.6.28.7-smp #1 SMP Sat Feb 28 12:26:08)
> whit dnsmasq (Dnsmasq version 2.47) and 3 vlans, so I have one file per vlan
> ir
> order to act as a dhcp server in each virtual interface
> The reason for having 3 diferents networks is for security, so:
> the configs it's as follows
>
> cat /etc/dnsmasq.conf
> dhcp-lease-max=5000
> log-dhcp
> conf-dir=/etc/dnsmasq.d
>
> cat /etc/dnsmasq.d/red_uno
> domain-needed
> bogus-priv
> interface=lo
> interface=eth0.100
> dhcp-range=red_uno,10.0.100.0,10.0.255.255,12h
> domain=itba.edu.ar,10.0.0.0/16
> # Opcion 44: Servidores WINS
> dhcp-option=net:red_uno,44,10.0.0.66
>
> cat /etc/dnsmasq.d/red_dos
> domain-needed
> bogus-priv
> interface=lo
> interface=eth0.200
> domain=alu.itba.edu.ar,172.17.0.0/16
> dhcp-range=red_dos,172.17.24.0,172.17.25.255,12h
> # Opcion 44: Servidores WINS
> dhcp-option=net:red_dos,44,172.17.8.16
>
> cat /etc/dnsmasq.d/red_tres
> domain-needed
> bogus-priv
> interface=lo
> interface=eth0.300
> dhcp-range=red_tres,10.2.1.0,10.2.100.255,12h
> domain=lanwifi.itba.edu.ar,10.2.0.0/16
>
> So, the problems become when a host of a network request an ip, and the
> service
> responds offering 3 diferent ips, one of each network !
> for example: the mac-address of client is 00:13:20:da:ab:69 and it's belong to
> "/etc/dnsmasq.d/red_dos" so the valid range is
> 172.17.24.0,172.17.25.255 and look what it happens then:
> grep 00:13:20:da:ab:69 /var/log/dnsmasq/dnsmasq.log
>
> May 31 09:09:21 skoll dnsmasq[3379]: DHCPDISCOVER(eth0.100) 169.254.217.131
> 00:13:20:da:ab:69
> May 31 09:09:21 skoll dnsmasq[3379]: DHCPOFFER(eth0.100) 10.0.235.33
> 00:13:20:da:ab:69
> May 31 09:09:24 skoll dnsmasq[3379]: DHCPDISCOVER(eth0.200) 169.254.217.131
> 00:13:20:da:ab:69
> May 31 09:09:24 skoll dnsmasq[3379]: DHCPOFFER(eth0.200) 172.17.25.34
> 00:13:20:da:ab:69
> May 31 09:09:27 skoll dnsmasq[3379]: DHCPDISCOVER(eth0.300) 169.254.217.131
> 00:13:20:da:ab:69
> May 31 09:09:27 skoll dnsmasq[3379]: DHCPOFFER(eth0.300) 10.2.68.33
> 00:13:20:da:ab:69
> May 31 09:09:27 skoll dnsmasq[3379]: DHCPDISCOVER(eth0.100) 169.254.217.131
> 00:13:20:da:ab:69
> May 31 09:09:27 skoll dnsmasq[3379]: DHCPOFFER(eth0.100) 10.0.235.33
> 00:13:20:da:ab:69
> May 31 09:09:27 skoll dnsmasq[3379]: DHCPDISCOVER(eth0.200) 169.254.217.131
> 00:13:20:da:ab:69
> May 31 09:09:27 skoll dnsmasq[3379]: DHCPOFFER(eth0.200) 172.17.25.34
> 00:13:20:da:ab:69
> May 31 09:09:27 skoll dnsmasq[3379]: DHCPDISCOVER(eth0.300) 169.254.217.131
> 00:13:20:da:ab:69
> May 31 09:09:27 skoll dnsmasq[3379]: DHCPOFFER(eth0.300) 10.2.68.33
> 00:13:20:da:ab:69
> May 31 09:09:28 skoll dnsmasq[3379]: DHCPREQUEST(eth0.100) 10.0.235.33
> 00:13:20:da:ab:69
> May 31 09:09:28 skoll dnsmasq[3379]: DHCPACK(eth0.100) 10.0.235.33
> 00:13:20:da:ab:69 labb14
> May 31 09:09:29 skoll dnsmasq[3379]: DHCPREQUEST(eth0.100) 10.0.235.33
> 00:13:20:da:ab:69
> May 31 09:09:29 skoll dnsmasq[3379]: DHCPACK(eth0.100) 10.0.235.33
> 00:13:20:da:ab:69 labb14
> May 31 09:10:37 skoll dnsmasq[3379]: DHCPINFORM(eth0.100) 10.0.235.33
> 00:13:20:da:ab:69
> May 31 09:10:37 skoll dnsmasq[3379]: DHCPACK(eth0.100) 10.0.235.33
> 00:13:20:da:ab:69 labb14
> May 31 09:12:38 skoll dnsmasq[3379]: DHCPREQUEST(eth0.100) 10.0.235.33
> 00:13:20:da:ab:69
> May 31 09:12:38 skoll dnsmasq[3379]: DHCPACK(eth0.100) 10.0.235.33
> 00:13:20:da:ab:69 labb14
> May 31 09:12:38 skoll dnsmasq[3379]: DHCPREQUEST(eth0.200) 10.0.235.33
> 00:13:20:da:ab:69
> May 31 09:12:38 skoll dnsmasq[3379]: DHCPNAK(eth0.200) 10.0.235.33
> 00:13:20:da:ab:69 wrong network
> May 31 09:12:38 skoll dnsmasq[3379]: DHCPREQUEST(eth0.300) 10.0.235.33
> 00:13:20:da:ab:69
> May 31 09:12:38 skoll dnsmasq[3379]: DHCPNAK(eth0.300) 10.0.235.33
> 00:13:20:da:ab:69 wrong network
> May 31 09:12:42 skoll dnsmasq[3379]: DHCPREQUEST(eth0.100) 10.0.235.33
> 00:13:20:da:ab:69
> May 31 09:12:42 skoll dnsmasq[3379]: DHCPACK(eth0.100) 10.0.235.33
> 00:13:20:da:ab:69 labb14
> May 31 09:12:42 skoll dnsmasq[3379]: DHCPREQUEST(eth0.200) 10.0.235.33
> 00:13:20:da:ab:69
> May 31 09:12:42 skoll dnsmasq[3379]: DHCPNAK(eth0.200) 10.0.235.33
> 00:13:20:da:ab:69 wrong network
> May 31 09:12:42 skoll dnsmasq[3379]: DHCPREQUEST(eth0.300) 10.0.235.33
> 00:13:20:da:ab:69
> May 31 09:12:42 skoll dnsmasq[3379]: DHCPNAK(eth0.300) 10.0.235.33
> 00:13:20:da:ab:69 wrong network
> May 31 09:16:25 skoll dnsmasq[3379]: DHCPINFORM(eth0.100) 10.0.235.33
> 00:13:20:da:ab:69
> May 31 09:16:25 skoll dnsmasq[3379]: DHCPACK(eth0.100) 10.0.235.33
> 00:13:20:da:ab:69 labb14
> May 31 09:16:25 skoll dnsmasq[3379]: DHCPINFORM(eth0.100) 10.0.235.33
> 00:13:20:da:ab:69
> May 31 09:16:25 skoll dnsmasq[3379]: DHCPACK(eth0.100) 10.0.235.33
> 00:13:20:da:ab:69 labb14
> May 31 11:50:35 skoll dnsmasq[20676]: DHCPREQUEST(eth0.100) 10.0.235.33
> 00:13:20:da:ab:69
> May 31 11:50:35 skoll dnsmasq[20676]: DHCPACK(eth0.100) 10.0.235.33
> 00:13:20:da:ab:69 labb14
> May 31 11:50:36 skoll dnsmasq[20676]: DHCPREQUEST(eth0.200) 10.0.235.33
> 00:13:20:da:ab:69
> May 31 11:50:36 skoll dnsmasq[20676]: DHCPNAK(eth0.200) 10.0.235.33
> 00:13:20:da:ab:69 wrong network
> May 31 11:50:36 skoll dnsmasq[20676]: DHCPREQUEST(eth0.300) 10.0.235.33
> 00:13:20:da:ab:69
> May 31 11:50:36 skoll dnsmasq[20676]: DHCPNAK(eth0.300) 10.0.235.33
> 00:13:20:da:ab:69 wrong network
>
>
> What is wrong here ?

The DHCP server in dnsmasq ia a simple one intended for a
simple single network. Install a dedicated DHCP server
instead and disable the DHCP service in dnsmasq.

How do you intend to tell the server which VLAN a
client is intended to go? The operating system
is not telling the server which VLAN was used
for the requests.

--

Tauno Voipio
tauno voipio (at) iki fi

From: Pascal Hambourg on 1 Jun 2010 09:17
Hello,

Tauno Voipio a �crit :
>
> The DHCP server in dnsmasq ia a simple one intended for a
> simple single network. Install a dedicated DHCP server
> instead and disable the DHCP service in dnsmasq.

Or maybe each VLAN should have a dedicated instance of dnsmasq serving a
single IP subnet.

> How do you intend to tell the server which VLAN a
> client is intended to go? The operating system
> is not telling the server which VLAN was used
> for the requests.

According to the log, it is. What puzzles me is how the hell the same
request is received on each VLAN.
From: itba on 1 Jun 2010 09:31
Tauno Voipio wrote on 06/01/2010 01:34 ET :
> On 31.5.10 8:29 , itba wrote:
>> Hello,
>> I have a production server running a slackware (
>> Linux skoll 2.6.28.7-smp #1 SMP Sat Feb 28 12:26:08)
>> whit dnsmasq (Dnsmasq version 2.47) and 3 vlans, so I have one file per vlan
>> ir
>> order to act as a dhcp server in each virtual interface
>> The reason for having 3 diferents networks is for security, so:
>> the configs it's as follows
>>
>> cat /etc/dnsmasq.conf
>> dhcp-lease-maxP00
>> log-dhcp
>> conf-dir=/etc/dnsmasq.d
>>
>> cat /etc/dnsmasq.d/red_uno
>> domain-needed
>> bogus-priv
>> interface=lo
>> interface=eth0.100
>> dhcp-range=red_uno,10.0.100.0,10.0.255.255,12h
>> domain=itba.edu.ar,10.0.0.0/16
>> # Opcion 44: Servidores WINS
>> dhcp-option=net:red_uno,44,10.0.0.66
>>
>> cat /etc/dnsmasq.d/red_dos
>> domain-needed
>> bogus-priv
>> interface=lo
>> interface=eth0.200
>> domain=alu.itba.edu.ar,172.17.0.0/16
>> dhcp-range=red_dos,172.17.24.0,172.17.25.255,12h
>> # Opcion 44: Servidores WINS
>> dhcp-option=net:red_dos,44,172.17.8.16
>>
>> cat /etc/dnsmasq.d/red_tres
>> domain-needed
>> bogus-priv
>> interface=lo
>> interface=eth0.300
>> dhcp-range=red_tres,10.2.1.0,10.2.100.255,12h
>> domain=lanwifi.itba.edu.ar,10.2.0.0/16
>>
>> So, the problems become when a host of a network request an ip, and the
>> service
>> responds offering 3 diferent ips, one of each network !
>> for example: the mac-address of client is 00:13:20:da:ab:69 and it's belong
to
>> "/etc/dnsmasq.d/red_dos" so the valid range is
>> 172.17.24.0,172.17.25.255 and look what it happens then:
>> grep 00:13:20:da:ab:69 /var/log/dnsmasq/dnsmasq.log
>>
>> May 31 09:09:21 skoll dnsmasq[3379]: DHCPDISCOVER(eth0.100) 169.254.217.131
>> 00:13:20:da:ab:69
>> May 31 09:09:21 skoll dnsmasq[3379]: DHCPOFFER(eth0.100) 10.0.235.33
>> 00:13:20:da:ab:69
>> May 31 09:09:24 skoll dnsmasq[3379]: DHCPDISCOVER(eth0.200) 169.254.217.131
>> 00:13:20:da:ab:69
>> May 31 09:09:24 skoll dnsmasq[3379]: DHCPOFFER(eth0.200) 172.17.25.34
>> 00:13:20:da:ab:69
>> May 31 09:09:27 skoll dnsmasq[3379]: DHCPDISCOVER(eth0.300) 169.254.217.131
>> 00:13:20:da:ab:69
>> May 31 09:09:27 skoll dnsmasq[3379]: DHCPOFFER(eth0.300) 10.2.68.33
>> 00:13:20:da:ab:69
>> May 31 09:09:27 skoll dnsmasq[3379]: DHCPDISCOVER(eth0.100) 169.254.217.131
>> 00:13:20:da:ab:69
>> May 31 09:09:27 skoll dnsmasq[3379]: DHCPOFFER(eth0.100) 10.0.235.33
>> 00:13:20:da:ab:69
>> May 31 09:09:27 skoll dnsmasq[3379]: DHCPDISCOVER(eth0.200) 169.254.217.131
>> 00:13:20:da:ab:69
>> May 31 09:09:27 skoll dnsmasq[3379]: DHCPOFFER(eth0.200) 172.17.25.34
>> 00:13:20:da:ab:69
>> May 31 09:09:27 skoll dnsmasq[3379]: DHCPDISCOVER(eth0.300) 169.254.217.131
>> 00:13:20:da:ab:69
>> May 31 09:09:27 skoll dnsmasq[3379]: DHCPOFFER(eth0.300) 10.2.68.33
>> 00:13:20:da:ab:69
>> May 31 09:09:28 skoll dnsmasq[3379]: DHCPREQUEST(eth0.100) 10.0.235.33
>> 00:13:20:da:ab:69
>> May 31 09:09:28 skoll dnsmasq[3379]: DHCPACK(eth0.100) 10.0.235.33
>> 00:13:20:da:ab:69 labb14
>> May 31 09:09:29 skoll dnsmasq[3379]: DHCPREQUEST(eth0.100) 10.0.235.33
>> 00:13:20:da:ab:69
>> May 31 09:09:29 skoll dnsmasq[3379]: DHCPACK(eth0.100) 10.0.235.33
>> 00:13:20:da:ab:69 labb14
>> May 31 09:10:37 skoll dnsmasq[3379]: DHCPINFORM(eth0.100) 10.0.235.33
>> 00:13:20:da:ab:69
>> May 31 09:10:37 skoll dnsmasq[3379]: DHCPACK(eth0.100) 10.0.235.33
>> 00:13:20:da:ab:69 labb14
>> May 31 09:12:38 skoll dnsmasq[3379]: DHCPREQUEST(eth0.100) 10.0.235.33
>> 00:13:20:da:ab:69
>> May 31 09:12:38 skoll dnsmasq[3379]: DHCPACK(eth0.100) 10.0.235.33
>> 00:13:20:da:ab:69 labb14
>> May 31 09:12:38 skoll dnsmasq[3379]: DHCPREQUEST(eth0.200) 10.0.235.33
>> 00:13:20:da:ab:69
>> May 31 09:12:38 skoll dnsmasq[3379]: DHCPNAK(eth0.200) 10.0.235.33
>> 00:13:20:da:ab:69 wrong network
>> May 31 09:12:38 skoll dnsmasq[3379]: DHCPREQUEST(eth0.300) 10.0.235.33
>> 00:13:20:da:ab:69
>> May 31 09:12:38 skoll dnsmasq[3379]: DHCPNAK(eth0.300) 10.0.235.33
>> 00:13:20:da:ab:69 wrong network
>> May 31 09:12:42 skoll dnsmasq[3379]: DHCPREQUEST(eth0.100) 10.0.235.33
>> 00:13:20:da:ab:69
>> May 31 09:12:42 skoll dnsmasq[3379]: DHCPACK(eth0.100) 10.0.235.33
>> 00:13:20:da:ab:69 labb14
>> May 31 09:12:42 skoll dnsmasq[3379]: DHCPREQUEST(eth0.200) 10.0.235.33
>> 00:13:20:da:ab:69
>> May 31 09:12:42 skoll dnsmasq[3379]: DHCPNAK(eth0.200) 10.0.235.33
>> 00:13:20:da:ab:69 wrong network
>> May 31 09:12:42 skoll dnsmasq[3379]: DHCPREQUEST(eth0.300) 10.0.235.33
>> 00:13:20:da:ab:69
>> May 31 09:12:42 skoll dnsmasq[3379]: DHCPNAK(eth0.300) 10.0.235.33
>> 00:13:20:da:ab:69 wrong network
>> May 31 09:16:25 skoll dnsmasq[3379]: DHCPINFORM(eth0.100) 10.0.235.33
>> 00:13:20:da:ab:69
>> May 31 09:16:25 skoll dnsmasq[3379]: DHCPACK(eth0.100) 10.0.235.33
>> 00:13:20:da:ab:69 labb14
>> May 31 09:16:25 skoll dnsmasq[3379]: DHCPINFORM(eth0.100) 10.0.235.33
>> 00:13:20:da:ab:69
>> May 31 09:16:25 skoll dnsmasq[3379]: DHCPACK(eth0.100) 10.0.235.33
>> 00:13:20:da:ab:69 labb14
>> May 31 11:50:35 skoll dnsmasq[20676]: DHCPREQUEST(eth0.100) 10.0.235.33
>> 00:13:20:da:ab:69
>> May 31 11:50:35 skoll dnsmasq[20676]: DHCPACK(eth0.100) 10.0.235.33
>> 00:13:20:da:ab:69 labb14
>> May 31 11:50:36 skoll dnsmasq[20676]: DHCPREQUEST(eth0.200) 10.0.235.33
>> 00:13:20:da:ab:69
>> May 31 11:50:36 skoll dnsmasq[20676]: DHCPNAK(eth0.200) 10.0.235.33
>> 00:13:20:da:ab:69 wrong network
>> May 31 11:50:36 skoll dnsmasq[20676]: DHCPREQUEST(eth0.300) 10.0.235.33
>> 00:13:20:da:ab:69
>> May 31 11:50:36 skoll dnsmasq[20676]: DHCPNAK(eth0.300) 10.0.235.33
>> 00:13:20:da:ab:69 wrong network
>>
>>
>> What is wrong here ?
>>
>>
>>
> The DHCP server in dnsmasq ia a simple one intended for a
> simple single network. Install a dedicated DHCP server
> instead and disable the DHCP service in dnsmasq.
>
> How do you intend to tell the server which VLAN a
> client is intended to go? The operating system
> is not telling the server which VLAN was used
> for the requests.
>
>
> Tauno Voipio
> tauno voipio (at) iki fi
>
Hi Tauno, thanks for reply my post,

"The DHCP server in dnsmasq ia a simple one intended for a
simple single network. Install a dedicated DHCP server
instead and disable the DHCP service in dnsmasq."
Yes, I know, you are right about that,
however among all my nets I reach near 300-400 hosts,
allegedly it would be enough for dnsmasq (less than 1000 host, according I
readed somewhere)

"How do you intend to tell the server which VLAN a
client is intended to go? The operating system
is not telling the server which VLAN was used
for the requests."
Well, I think that this is the real trouble whit all this.
So, the question 1 would be: If I'm telling to dnsmasq to listen
in eth0.100 (one of three pools), why then dnsmasq will offer
ips from others pools (like eth0.200 and eth0.300) ???
And the question 2, the job of telling to dnsmasq which subinterface is,
isn't for Operative System ?
From: Tauno Voipio on 1 Jun 2010 09:43
On 1.6.10 4:17 , Pascal Hambourg wrote:
> Hello,
>
> Tauno Voipio a �crit :
>>
>> The DHCP server in dnsmasq ia a simple one intended for a
>> simple single network. Install a dedicated DHCP server
>> instead and disable the DHCP service in dnsmasq.
>
> Or maybe each VLAN should have a dedicated instance of dnsmasq serving a
> single IP subnet.
>
>> How do you intend to tell the server which VLAN a
>> client is intended to go? The operating system
>> is not telling the server which VLAN was used
>> for the requests.
>
> According to the log, it is. What puzzles me is how the hell the same
> request is received on each VLAN.


The DHCPDISCOVER message is an UDP broadcast. It seems to me that
the VLAN association is not forwarded to the server process, but
it responds to the broadcast with all the associations it knows.

Getting multiple DHCPOFFERS is not a breach of the DHCP protocol.
The client is free to pick the server it wants to proceed with.

The DHCP server in dnsmasq is a rudimentary one. Please start with
a dedicated DHCP server, like dhcp3.

--

Tauno Voipio
tauno voipio (at) iki fi
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