Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

IP Helper-address

I have a network with mutiple vlans multiple dhcp servers. Someone else set it up but is unavailable to make the any changes. I would like to use a network that was shutdown vlan 26/192.168.26.x/23 see the config below. I have the dhcp server 192.168.26.0 length 23 I changed one of the interfaces to that vlan and i am not getting a dhcp address. I can ping the dhcp server 192.168.16.12.
 

!
interface GigabitEthernet1/0/27
 switchport access vlan 26

interface Vlan1
 ip address 192.168.29.1 255.255.255.0
 ip helper-address 192.168.28.2
!
interface Vlan2
 description CBT Internet
 ip address 66.42.138.142 255.255.255.224
 shutdown
!
interface Vlan5
 ip address 192.168.5.1 255.255.255.0
!
interface Vlan9
 description OldSAN Do Not ShutDown
 ip address 192.168.6.1 255.255.255.0
!
interface Vlan16
 description Servers
 ip address 192.168.30.1 255.255.255.0 secondary
 ip address 192.168.16.1 255.255.255.0
!
interface Vlan19
 description AspectServers
 ip address 192.168.19.1 255.255.255.0
!
interface Vlan21
 description Wireless
 ip address 192.168.21.1 255.255.255.0
 shutdown
!
interface Vlan24
 ip address 192.168.24.1 255.255.255.0
!
interface Vlan26
 ip address 192.168.26.1 255.255.254.0
 ip helper-address 192.168.16.12
!
interface Vlan28
 description ShoreTel
 ip address 192.168.28.1 255.255.255.0
!
interface Vlan121
 ip address 192.168.121.1 255.255.255.0
!
ip classless
ip route 0.0.0.0 0.0.0.0 192.168.16.4
ip route 192.168.120.0 255.255.255.0 192.168.16.4
no ip http server
no ip http secure-server

 

Thank you for any help you can provide

6 REPLIES

If this is your interface

If this is your interface config

interface GigabitEthernet1/0/27
 switchport access vlan 26

you need to add switchport mode access

New Member

Yes that is the interface how

Yes that is the interface how could i forget the mode let me change it.

Silver

Hi there, Cisco has DTP

Hi there, 

Cisco has DTP enabled by default set to "auto" if connected to a server or PC it will automatically go to access.

Nonetheless, try hardcoding it into access see if it works

Based on your config, can you verify your DHCP server IP?
You stated in your problem that it is 192.168.16.12, but in your configuration it is 192.168.16.2

Kindly check and change if necessary.

 

 

Don't forget to rate or mark as correct helpful post! :)

New Member

I check switchport mode

I check switchport mode access that isnt it. I dont see 192.168.16.2 where do you see that?

Silver

interface Vlan1 ip address

interface Vlan1
 ip address 192.168.29.1 255.255.255.0
 ip helper-address 192.168.28.2

Please verify your configuration

New Member

This ^^, it doesn't matter,

This ^^, it doesn't matter, it will still work, however, in the interests of security all access ports should be configured as such.

OP, how do you know your DHCP server is working correctly?

Martin

99
Views
0
Helpful
6
Replies
CreatePlease login to create content