Problem with DHCP server providing IP address

[m-abooali]

                  hi,

a new LAN installation, two VSS pair 6509 core, 15 closets, with 3750 stacks. Floor 15 only, devices/hosts can ping teh DHCP server but cannot aquire IP addresses. no such problem on other floors?

portfast an dother parameters are intact.

your thoughts with be appreciated.

Masood

[networksupport · Accepted solution]

Are the trunks going to the closet switches allowing the vlan the DHCP server is in?


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[m-abooali]

I am not sure but I don't thik so!?

what commands must be under the trunk link?

Regards,.

Masood

[m-abooali]

I am sorry, yes.

it does alloow te VLAn the DHCP server is in.

masood

[mvsheik123 · Accepted solution]

Hi,

If all you config on L3 interfaces are correct (helper address), make sure DHCP scope is activated in DHCP server and the scope got enough IPs for the vlan/subnet.

hth

MS

[Sebastian Helmer · Accepted solution]

Did you install the "ip helper-address" with the DHCP Server IP on the SVI for the clients off the problem floor?

Maybe u give us an overview about your design (VLANs and IP-Ranges)

[m-abooali]

I assume they had but I will check into it. I am not on site.

Thanks,

Masood

[m-abooali]

even changing vlan and subnet on that specific floor deosn't work, Static IP or DHCP!?

I had them try that vlan and subnet on a differnet  floor and it works so teh cofiguration of that vlan is correct. from teh  switch prompt on that floor they can ping everywhere no problem but no  host regardless of which vlan and subnet doesn't work on tha floor?

they had used single mode fiber and SFPs in teh entire bukding so could it be the fiber and distance, etc.?

Thanks,

Masood

[m-abooali]

its all goo dnoe. they had a doifferent vlan as "allowed" under the trunk configuration. removing that resolved the issue.

Thanks so much for taking the respoding to my question.

Regards,

Masood

[Sebastian Helmer · Accepted solution]

would u rate, if it was helpful.

[m-abooali]

thanks everyone for your thoughful answers and all were right answers.

I was not on site and was relying on the info getting form the person on-site. they had a wrong vlan name under the trunk port facing the server on teh VSS pair.

removing that command line took care of the problem

Thank you all.

Masood