06-05-2013 02:58 AM - edited 03-07-2019 01:43 PM
i am not getting ip add from the dhcp server ,
if i am adding the dhcp server to vlan 50 then only i am getting ip add
i am having two vlan 50 and vlan 51
so can any one help me what is the isssue i am attaching my network diagram and configuration
core switch configuration
Switch#sho run
Building configuration...
Current configuration : 2964 bytes
!
version 12.2
no service timestamps log datetime msec
no service timestamps debug datetime msec
no service password-encryption
!
hostname Switch
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!
!
!
!
ip routing
!
!
!
!
!
!
!
!
!
!
!
!
!
!
interface FastEthernet0/1
channel-group 1 mode on
switchport trunk encapsulation dot1q
switchport mode trunk
!
interface FastEthernet0/2
channel-group 1 mode on
switchport trunk encapsulation dot1q
switchport mode trunk
!
interface FastEthernet0/3
channel-group 1 mode on
switchport trunk encapsulation dot1q
switchport mode trunk
!
interface FastEthernet0/4
channel-group 1 mode on
switchport trunk encapsulation dot1q
switchport mode trunk
!
interface FastEthernet0/5
channel-group 2 mode on
switchport trunk encapsulation dot1q
switchport mode trunk
!
interface FastEthernet0/6
channel-group 2 mode on
switchport trunk encapsulation dot1q
switchport mode trunk
!
interface FastEthernet0/7
channel-group 2 mode on
switchport trunk encapsulation dot1q
switchport mode trunk
!
interface FastEthernet0/8
channel-group 2 mode on
switchport trunk encapsulation dot1q
switchport mode trunk
!
interface FastEthernet0/9
channel-group 3 mode on
switchport trunk encapsulation dot1q
switchport mode trunk
!
interface FastEthernet0/10
channel-group 3 mode on
switchport trunk encapsulation dot1q
switchport mode trunk
!
interface FastEthernet0/11
channel-group 3 mode on
switchport trunk encapsulation dot1q
switchport mode trunk
!
interface FastEthernet0/12
channel-group 3 mode on
switchport trunk encapsulation dot1q
switchport mode trunk
!
interface FastEthernet0/13
channel-group 4 mode on
switchport trunk encapsulation dot1q
switchport mode trunk
!
interface FastEthernet0/14
channel-group 4 mode on
switchport trunk encapsulation dot1q
switchport mode trunk
!
interface FastEthernet0/15
channel-group 4 mode on
switchport trunk encapsulation dot1q
switchport mode trunk
!
interface FastEthernet0/16
channel-group 4 mode on
switchport trunk encapsulation dot1q
switchport mode trunk
!
interface FastEthernet0/17
!
interface FastEthernet0/18
!
interface FastEthernet0/19
!
interface FastEthernet0/20
!
interface FastEthernet0/21
!
interface FastEthernet0/22
!
interface FastEthernet0/23
!
interface FastEthernet0/24
!
interface GigabitEthernet0/1
!
interface GigabitEthernet0/2
!
interface Port-channel 1
switchport trunk encapsulation dot1q
switchport mode trunk
!
interface Port-channel 2
switchport trunk encapsulation dot1q
switchport mode trunk
!
interface Port-channel 3
switchport trunk encapsulation dot1q
switchport mode trunk
!
interface Port-channel 4
switchport trunk encapsulation dot1q
switchport mode trunk
!
interface Vlan1
no ip address
shutdown
!
interface Vlan50
ip address 192.168.50.1 255.255.255.0
ip helper-address 192.168.50.2
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interface Vlan51
ip address 192.168.51.1 255.255.255.0
ip helper-address 192.168.50.2
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ip classless
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!
!
!
!
!
!
line con 0
line vty 0 4
login
!
!
!
end
LAYER 2 SW-1
Building configuration...
Current configuration : 1834 bytes
!
version 12.2
no service timestamps log datetime msec
no service timestamps debug datetime msec
no service password-encryption
!
hostname Switch
!
!
!
interface FastEthernet0/1
channel-group 1 mode on
switchport mode trunk
!
interface FastEthernet0/2
channel-group 1 mode on
switchport mode trunk
!
interface FastEthernet0/3
channel-group 1 mode on
switchport mode trunk
!
interface FastEthernet0/4
channel-group 1 mode on
switchport mode trunk
!
interface FastEthernet0/5
switchport access vlan 50
description DHCP SERVER
!
interface FastEthernet0/6
switchport access vlan 50
!
interface FastEthernet0/7
switchport access vlan 50
!
interface FastEthernet0/8
switchport access vlan 50
!
interface FastEthernet0/9
switchport access vlan 50
!
interface FastEthernet0/10
switchport access vlan 50
!
interface FastEthernet0/11
switchport access vlan 50
!
interface FastEthernet0/12
switchport access vlan 50
!
interface FastEthernet0/13
switchport access vlan 50
!
interface FastEthernet0/14
switchport access vlan 50
!
interface FastEthernet0/15
switchport access vlan 50
!
interface FastEthernet0/16
switchport access vlan 50
!
interface FastEthernet0/17
switchport access vlan 50
!
interface FastEthernet0/18
switchport access vlan 50
!
interface FastEthernet0/19
switchport access vlan 50
!
interface FastEthernet0/20
switchport access vlan 50
!
interface FastEthernet0/21
switchport access vlan 50
!
interface FastEthernet0/22
switchport access vlan 50
!
interface FastEthernet0/23
switchport access vlan 50
!
interface FastEthernet0/24
switchport access vlan 50
!
interface GigabitEthernet1/1
!
interface GigabitEthernet1/2
!
interface Port-channel 1
!
interface Vlan1
no ip address
shutdown
!
interface Vlan50
no ip address
ip helper-address 192.168.50.2
!
!
line con 0
!
line vty 0 4
login
line vty 5 15
login
!
!
end
LAYER 2 SW-2
Building configuration...
Current configuration : 1834 bytes
!
version 12.2
no service timestamps log datetime msec
no service timestamps debug datetime msec
no service password-encryption
!
hostname Switch
!
!
!
interface FastEthernet0/1
channel-group 2 mode on
switchport mode trunk
!
interface FastEthernet0/2
channel-group 2 mode on
switchport mode trunk
!
interface FastEthernet0/3
channel-group 2 mode on
switchport mode trunk
!
interface FastEthernet0/4
channel-group 2 mode on
switchport mode trunk
!
interface FastEthernet0/5
switchport access vlan 51
!
interface FastEthernet0/6
switchport access vlan 51
!
interface FastEthernet0/7
switchport access vlan 51
!
interface FastEthernet0/8
switchport access vlan 51
!
interface FastEthernet0/9
switchport access vlan 51
!
interface FastEthernet0/10
switchport access vlan 51
!
interface FastEthernet0/11
switchport access vlan 51
!
interface FastEthernet0/12
switchport access vlan 51
!
interface FastEthernet0/13
switchport access vlan 51
!
interface FastEthernet0/14
switchport access vlan 51
!
interface FastEthernet0/15
switchport access vlan 51
!
interface FastEthernet0/16
switchport access vlan 51
!
interface FastEthernet0/17
switchport access vlan 51
!
interface FastEthernet0/18
switchport access vlan 51
!
interface FastEthernet0/19
switchport access vlan 51
!
interface FastEthernet0/20
switchport access vlan 51
!
interface FastEthernet0/21
switchport access vlan 51
!
interface FastEthernet0/22
switchport access vlan 51
!
interface FastEthernet0/23
switchport access vlan 51
!
interface FastEthernet0/24
switchport access vlan 51
!
interface GigabitEthernet1/1
!
interface GigabitEthernet1/2
!
interface Port-channel 2
!
interface Vlan1
no ip address
shutdown
!
interface Vlan51
no ip address
ip helper-address 192.168.50.2
!
!
line con 0
!
line vty 0 4
login
line vty 5 15
login
!
!
end
06-05-2013 03:45 AM
Hi,
For DHCP relay agent to work you must enable the DHCP service with service DHCP global configuration mode command and your DHCP server must have a route for the IP of the interface where ip helper-address is configured and of course you must have the corresponding pool configured.
Regards
Alain
Don't forget to rate helpful posts.
06-05-2013 03:50 AM
Hi Mohammed,
Yes you are correct you need to add the command ip helper address under vlan on which you need to recieve the same.
Couple of things to be check:
ip dhcp server X.X.X.X >>> I hope this is there
service dhcp enable>>>> SErvice is enabled.
For example:
PC-----Switch----Router
PC---Obtain ip addres--------Port in access vlan 50------Switch( Int vlan 50, ip helper address 1.1.1.1)----router (DHCP server).
Ref:
http://www.cisco.com/en/US/docs/ios-xml/ios/ipaddr_dhcp/configuration/12-4t/config-dhcp-server.html
HTH
REgards
Inayath
06-05-2013 04:10 AM
service dhcp enable should be configure on all the switches or just core switch
i am having 1 core 4507 to which rem 4 layer 2 switch are connected
06-05-2013 04:50 AM
Hi,
it should be enabled on the switch acting as a Relay agent so your core switch.
Regards
Alain
Don't forget to rate helpful posts.
06-05-2013 04:57 AM
on Server.
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