4507R+e dhcp

[dgausepohl]

I have a 4507 where I have created several new vlan and dhcp pools on a windows 2008 server. When I configure a port for one of these new vlans I get a 169 address instead of the an address I expected.

Has anyone else had this problem?

[Jon Marshall]

Have you added the "ip helper-address ..." command under the SVIs ie. 

int vlan <x> 
ip address x.x.x.x y.y.y.y
ip helper-address <IP of DHCP server> 

Jon

[dgausepohl]

That would be too easy. Here is what the vlan that works

interface Vlan10
ip address 10.181.128.1 255.255.240.0 secondary
ip address 10.10.0.1 255.255.0.0
ip helper-address 10.1.0.98
ip helper-address 10.1.0.116
ip helper-address 10.1.0.97
ip helper-address 10.1.0.96
ip helper-address 10.1.1.37
no ip redirects
ip policy route-map NewNet

here is the one that doesn't work:

interface Vlan93
description SCS Wireless Management
ip address 10.181.171.1 255.255.255.0
ip helper-address 10.1.0.218
ip helper-address 10.1.0.98
ip helper-address 10.1.0.97
!

[Jon Marshall · Accepted solution]

Do you have any devices with static IPs in vlan 93 to confirm it is working ? 

Has the vlan been created on all necessary switches (if any) and added to trunk links etc. 

Jon

[Georg Pauwen]

Hello,

what are the multiple helper-addresses for ? What does the PBR do on the working interface ?

[dgausepohl]

No, I did not try a static addressed device to see if the vlan works. You may have hit a point where the dhcp server may not have the vlans on the switch that they are connect to.

I do not have a very good understanding of this site. I think everything was installed in 2015, and hasn't been touched since.

i logged into the dhcp server and got the MAC, found that it lived on another switch. Went to that switch, add the vlans, the saw that it was port-channeled. The port channel only allowed certain vlans, added the new vlans. 

Now I have the question, where are all the other vlans that are not in that port channel getting their ip addresses. Also they don't include the dhcp server that I am using. Very strange, the local person doesn't know either.

[Jon Marshall]

Difficult to say without knowing the site but there are lot of ip helper-address commands under the SVIs so there may be other servers you are not aware of. 

Could also be network device with DHCP pools setup that is also handing out these IPs. 

I would start at the L3 switch responsible for routing between vlans and try and trace it from there. 

Jon

[dgausepohl]

The PBR has to do with the phones. Not sure why they just didn't use switchport voice vlan XX for the phones.