Windows DHCP - Multi vlan

[Leonardo Gonzaga]

Hello,

I have a multi vlan LAN where a Windows Svr is the DHCP. The below output shows the vlan interfaces with the ip helper and the interface connected to the server.

Still workstations are not getting IPs in any vlan.Please help.

...

interface GigabitEthernet1/0/42

description Link to Workstations
 switchport access vlan 6
 spanning-tree portfast

interface GigabitEthernet1/0/46
 description Link to DHCP Server (10.10.33.11)
 switchport mode trunk
 spanning-tree portfast

interface Vlan4
 description Link to SVR_PTR
 ip address 10.10.33.200 255.255.255.0

interface Vlan6
 description Link to WIRED
 ip address 10.10.35.1 255.255.255.0
 ip helper-address 10.10.33.11

interface Vlan7
 description link to WIRELESS USERS
 ip address 10.10.36.1 255.255.255.0
 ip helper-address 10.10.33.11

[Jon Marshall]

Why is the port for the DHCP server a trunk link ?

Jon

[Leonardo Gonzaga]

Hi Jon,

I thought it needed because the DHCP is giving IPs to more than one vlan. Is it right?

Leonardo

[Jon Marshall]

Leonardo

I thought it needed because the DHCP is giving IPs to more than one vlan

No, that is what your "ip helper-address .." commands do.

If the server is not trunking on it's network interface then you need to modify the configuration of the port connecting to the server ie. remove the trunk part and make it an access port in vlan 4.

Jon

[Leonardo Gonzaga]

Thanks Jon, I'll give it a try and let you know how it worked out.

[Leonardo Gonzaga]

Hello Jon,

I changed the conf. on the interface connected to the server to access on its proper vlan. Still I'm unable to get an ip.

Here's how the config looks now:

interface Vlan3
 description Link to CCTV
 ip address 10.10.32.129 255.255.255.224

interface Vlan4
 description Link to SVR_PTR
 ip address 10.10.33.200 255.255.255.0

interface Vlan6
 description Link to WIRED USERS
 ip address 10.10.35.250 255.255.255.0
 ip helper-address 10.10.33.11

interface Vlan7
 description link to WIRELESS USERS
 ip address 10.10.36.1 255.255.255.0
 ip helper-address 10.10.33.11

interface GigabitEthernet1/0/47
 description Link to HP Servers
 switchport access vlan 4
 switchport mode access
 spanning-tree portfast

interface GigabitEthernet1/0/17

description Link to User
 switchport access vlan 6
 switchport voice vlan 5
 spanning-tree portfast

[Jon Marshall]

Leonardo

Are you sure the scopes have been activated on the DHCP server ?

I assume you are using a scope per subnet ?

Also noticed you don't have an interface for vlan 5 with an ip helper-address, is tha just missing from your post ?

Jon

[Leonardo Gonzaga]

Hello Jon,

The scopes are all activated.

The interface vlan5 and ip helper do exist. I excluded from the post. 

I'll reset the switch to factory default and reconfigure . 

Will let you know how it goes.

Thanks,

[Leonardo Gonzaga]

Still Having problems:

This is what the debug looks like:

Reload workspace interface Vlan6 tableid 0.
Apr 16 17:36:25.703: DHCPD: tableid for 10.10.35.1 on Vlan6 is 0
Apr 16 17:36:25.703: DHCPD: client's VPN is .
Apr 16 17:36:25.703: DHCPD: DHCPREQUEST received from client 0100.2356.0c30.00.
Apr 16 17:36:25.703: DHCPD: Finding a relay for client 0100.2356.0c30.00 on interface Vlan6.
Apr 16 17:36:25.703: DHCPD: Looking up binding using address 10.10.35.1
Apr 16 17:36:25.703: DHCPD: setting giaddr to 10.10.35.1.
Apr 16 17:36:25.703: DHCPD: BOOTREQUEST from 0100.2356.0c30.00 forwarded to 10.10.33.11.

Can you see any anomaly?