Need Help DHCP Server

Fri Mar 15 21:15:42 UTC 2013

Greetings List,

someone please help, i have multi tenant DHCP server running on one Ubuntu
12.4LTS host. Setup, one physical interface (eth1) there is no ip address
on physical interface (eth1 using as trunk mode).

following static ip address are configured on logical interfaces, and all
five starts DHCP daemons starts up alright and issues ip address as
expected only when the "dhcpd.conf" is as following.

vlan10 ineterafce=192.168.10.10/24
vlan20 ineterafce=192.168.20.20/24
vlan30 ineterafce=192.168.30.30/24
vlan40 ineterafce=192.168.40.40/24
vlan50 ineterafce=192.168.50.50/24

# Vlan 10
subnet 192.168.11.0 netmask 255.255.255.0 {
 option routers 192.168.11.1;
 option subnet-mask 255.255.255.0;
 option broadcast-address 192.168.11.255;
 option domain-name-servers 41.211.0.41;
 option domain-name "teledataict.net";
 default-lease-time 3600;
 max-lease-time 7200;
 range 192.168.11.100 192.168.11.200;
}

# Vlan 20
subnet 192.168.21.0 netmask 255.255.255.0 {
 option routers 192.168.21.1;
 option subnet-mask 255.255.255.0;
 option broadcast-address 192.168.21.255;
 option domain-name-servers 41.211.0.41;
 option domain-name "teledataict.net";
 default-lease-time 3600;
 max-lease-time 7200;
 range 192.168.21.100 192.168.21.200;
}

# Vlan 30
subnet 192.168.31.0 netmask 255.255.255.0 {
 option routers 192.168.31.1;
 option subnet-mask 255.255.255.0;
 option broadcast-address 192.168.31.255;
 option domain-name-servers 41.211.0.41;
 option domain-name "teledataict.net";
 default-lease-time 3600;
 max-lease-time 7200;
 range 192.168.31.100 192.168.31.200;
}

# Vlan 40
subnet 192.168.41.0 netmask 255.255.255.0 {
 option routers 192.168.41.1;
 option subnet-mask 255.255.255.0;
 option broadcast-address 192.168.41.255;
 option domain-name-servers 41.211.0.41;
 option domain-name "teledataict.net";
 default-lease-time 3600;
 max-lease-time 7200;
 range 192.168.41.100 192.168.41.200;
}

# Vlan 50
subnet 192.168.51.0 netmask 255.255.255.0 {
 option routers 192.168.51.1;
 option subnet-mask 255.255.255.0;
 option broadcast-address 192.168.51.255;
 option domain-name-servers 41.211.0.41;
 option domain-name "teledataict.net";
 default-lease-time 3600;
 max-lease-time 7200;
 range 192.168.51.100 192.168.51.200;
}

But we have the requirement where i need to issue ip address from the
range that is not configured on the server (request coming through dhcp
relay agent (bootp helper) from remote network) for example. Please mind
that ip address "192.168.61.x" is not configured on any interface of my
DHCP server ("/etc/network/interface"). If i was adding following code in
to the "dhcpd.conf" daemon fails to start. since this ip range (subnet) in
not my server, i have to issue these ip to remote client request came
through dhcp relay agent.

subnet 192.168.61.0 netmask 255.255.255.0 {
 option routers 192.168.61.1;
 option subnet-mask 255.255.255.0;
 option broadcast-address 192.168.61.255;
 option domain-name-servers 41.211.0.41;
 option domain-name "teledataict.net";
 default-lease-time 3600;
 max-lease-time 7200;
 range 192.168.61.100 192.168.61.200;
}

But following configuration solved the problem. i as able to issue ip
address for subnet "192.168.61.0" if configuration is like this.

subnet 192.168.0.0 netmask 255.255.0.0 {
 option routers 192.168.10.10;
 option subnet-mask 255.255.255.0;
 option broadcast-address 192.168.10.255;
 option domain-name-servers 41.211.0.41;
 option domain-name "teledataict.com";
 default-lease-time 3600;
 max-lease-time 7200;
 range 192.168.10.100 192.168.10.200;
}

subnet 192.168.0.0 netmask 255.255.0.0 {
 option routers 192.168.20.20;
 option subnet-mask 255.255.255.0;
 option broadcast-address 192.168.20.255;
 option domain-name-servers 41.211.0.41;
 option domain-name "teledataict.net";
 default-lease-time 3600;
 max-lease-time 7200;
 range 192.168.20.100 192.168.20.200;
}

subnet 192.168.0.0 netmask 255.255.0.0 {
 option routers 192.168.30.30;
 option subnet-mask 255.255.255.0;
 option broadcast-address 192.168.30.255;
 option domain-name-servers 41.211.0.41;
 option domain-name "teledataict.net";
 default-lease-time 3600;
 max-lease-time 7200;
 range 192.168.30.100 192.168.30.200;
}

subnet 192.168.0.0 netmask 255.255.0.0 {
 option routers 192.168.40.40;
 option subnet-mask 255.255.255.0;
 option broadcast-address 192.168.40.255;
 option domain-name-servers 41.211.0.41;
 option domain-name "teledataict.net";
 default-lease-time 3600;
 max-lease-time 7200;
 range 192.168.40.100 192.168.40.200;
}

subnet 192.168.0.0 netmask 255.255.0.0 {
 option routers 192.168.50.50;
 option subnet-mask 255.255.255.0;
 option broadcast-address 192.168.50.255;
 option domain-name-servers 41.211.0.41;
 option domain-name "teledataict.net";
 default-lease-time 3600;
 max-lease-time 7200;
 range 192.168.50.100 192.168.50.200;
}

But now the client from vlan10 get the ip from vlan20 scope & from vlan40
scope etc...

I badly need help to solve this problem, i am willing to learn but after
reading hundreds of posts unable to understand.

Warnings in Logs:

Mar 15 10:38:25 captive dhcpd: Internet Systems Consortium DHCP Server
4.1-ESV-R4
Mar 15 10:38:25 captive dhcpd: Copyright 2004-2011 Internet Systems
Consortium.
Mar 15 10:38:25 captive dhcpd: All rights reserved.
Mar 15 10:38:25 captive dhcpd: For info, please visit
https://www.isc.org/software/dhcp/
Mar 15 10:38:25 captive dhcpd: Warning: subnet 192.168.0.0/16 overlaps
subnet 192.168.0.0/16
Mar 15 10:38:25  dhcpd: last message repeated 3 times
Mar 15 10:38:25 captive dhcpd: Internet Systems Consortium DHCP Server
4.1-ESV-R4
Mar 15 10:38:25 captive dhcpd: Copyright 2004-2011 Internet Systems
Consortium.
Mar 15 10:38:25 captive dhcpd: All rights reserved.
Mar 15 10:38:25 captive dhcpd: For info, please visit
https://www.isc.org/software/dhcp/
Mar 15 10:38:25 captive dhcpd: Wrote 2 leases to leases file.
Mar 15 10:38:25 captive dhcpd: Multiple interfaces match the same subnet:
vlan40 vlan20
Mar 15 10:38:25 captive dhcpd: Multiple interfaces match the same shared
network: vlan40 vlan20
Mar 15 10:38:25 captive dhcpd: Multiple interfaces match the same subnet:
vlan40 vlan50
Mar 15 10:38:25 captive dhcpd: Multiple interfaces match the same shared
network: vlan40 vlan50
Mar 15 10:38:25 captive dhcpd: Multiple interfaces match the same subnet:
vlan40 vlan30
Mar 15 10:38:25 captive dhcpd: Multiple interfaces match the same shared
network: vlan40 vlan30
Mar 15 10:38:25 captive dhcpd: Multiple interfaces match the same subnet:
vlan40 vlan10
Mar 15 10:38:25 captive dhcpd: Multiple interfaces match the same shared
network: vlan40 vlan10

Thanks for attending to this request.
Regards