«
»

How to configure Cisco router to use Microsoft DHCP server Or Active Directory Server between vlans

Note :This is a router on a stick method (cisco 1941 router)

(a) Find out router interfaces

EVROUTER#show ip interface brief
Interface                  IP-Address      OK? Method Status                Prot
ocol
GigabitEthernet0/0         unassigned      YES manual up                    up
 
GigabitEthernet0/1         88.88.88.81    YES DHCP   up                    up
 
NVI0                       unassigned      NO  unset  up                    up

(b) Create Sub interface related to individuals vlan

For vlan1 
configure terminal
interface GigabitEthernet0/0.1
 encapsulation dot1Q 1
 ip address 192.168.1.1 255.255.255.0
 
For Vlan 10
configure terminal
interface GigabitEthernet0/0.10
 encapsulation dot1Q 10
 ip address 192.168.10.1 255.255.255.0
 
For Vlan 20
 
configure terminal
interface GigabitEthernet0/0.20
 encapsulation dot1Q 20
 ip address 192.168.20.1 255.255.255.0

output should be :

EVROUTER#show ip interface brief
Interface                  IP-Address      OK? Method Status                Prot
ocol
GigabitEthernet0/0         unassigned      YES manual up                    up
 
GigabitEthernet0/0.1       192.168.1.1        YES manual up                    up
 
GigabitEthernet0/0.10      192.168.10.1    YES manual up                    up
 
GigabitEthernet0/0.20      192.168.20.1    YES manual up                    up
 
GigabitEthernet0/1         88.88.88.81    YES DHCP   up                    up
 
NVI0                       unassigned      NO  unset  up                    up
 
EVROUTER#

(c)Setup the relay agent for individuals subnet

For vlan 1 
EVROUTER#configure terminal
EVROUTER(config)#interface gigabitEthernet 0/0.1
EVROUTER(config-subif)#ip helper-address 192.168.1.7
 
For Vlan10:
EVROUTER#configure terminal
EVROUTER(config)#interface gigabitEthernet 0/0.10
EVROUTER(config-subif)#ip helper-address 192.168.1.7
 
For vlan20
EVROUTER#configure terminal
EVROUTER(config)#interface gigabitEthernet 0/0.20
EVROUTER(config-subif)#ip helper-address 192.168.1.7

now all your vlans will be able to get Ip from each individuals subnet from DHCP server and they would be able to use active directory to login each computer with their user name and password.

(d) Allow each vlans to use internat
(1) label each interface and sub interface for NAT

     configure terminal	 
     interface gigabitEthernet 0/0.1 
     ip nat inside
     exit
      interface gigabitEthernet 0/0.10 
     ip nat inside
    exit
    interface gigabitEthernet 0/0.20 
     ip nat inside
    exit
     interface gigabitEthernet 0/1 
     ip nat outside
    exit

(2)Create Access list to allow this vlans to use NAT

     configure terminal
     ip access-list standard NAT_ADDRESS 
     permit 192.168.0.0 0.0.255.255

(3)Enable nat overload

   ip nat inside source list NAT_ADDRESS gigabitEthernet 0/1  overload

note : At this point all vlans will be able to get to the internet .

This entry was posted on Friday, July 9th, 2010 at 1:28 pm and is filed under Cisco Router/Switch. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

One Response to “How to configure Cisco router to use Microsoft DHCP server Or Active Directory Server between vlans”

  1. Ashwani says:
    July 10, 2010 at 9:16 pm

    Excellent article!!

    i”ll try to use it on GNS3 if i can :( ….this where i need real switches…lol

Leave a Reply