IP Helper Address on 3850

[cephasahiaku]

I am having issues with IP helper address,
I dont get IP from my DHCP but able to ping gateway on the vlan interface
MY DHCP SERVER ins on CentOS
DHCP ip 192.168.200.96
Router 192.168.200.1

On 3850
Trunk
Port Mode Encapsulation Status Native vlan

Gi1/0/3 on 802.1q trunking 1

Vlan
VLAN Name Status Ports
---- -------------------------------- --------- -------------------------------
1 default active Gi1/0/2, Gi1/0/9, Gi1/0/12
Gi1/0/14, Gi1/0/15, Gi1/0/16
Gi1/0/17, Gi1/0/18, Gi1/0/19
Gi1/0/20, Gi1/0/22, Gi1/0/23
Gi1/1/1, Gi1/1/2, Gi1/1/3
Gi1/1/4

22 Build_A active

interface Vlan22
description Building A SVI
ip address 192.168.202.1 255.255.255.0
ip helper-address 192.168.200.96

On 2969-X

interface GigabitEthernet1/0/25
description CONN TO 3850 -- Gi1/0/3

VLANS
VLAN Name Status Ports
---- -------------------------------- --------- -------------------------------
1 default active Gi1/0/11, Gi1/0/12, Gi1/0/13
Gi1/0/14, Gi1/0/15, Gi1/0/16
Gi1/0/17, Gi1/0/18, Gi1/0/19
Gi1/0/20, Gi1/0/21, Gi1/0/22
Gi1/0/23, Gi1/0/24, Gi1/0/26
Gi1/0/27, Gi1/0/28
XX XXXXX active
XX XXXX active
XX XXXXXXXXXXXX active
XX XXXXXXXXXXXX active
XX XXXXXXXX active
XX XXXXXXXX active
22 Build_A active Gi1/0/1, Gi1/0/2, Gi1/0/3
Gi1/0/4, Gi1/0/5, Gi1/0/6
Gi1/0/7, Gi1/0/8, Gi1/0/9
Gi1/0/10

Trunk
Port Mode Encapsulation Status Native vlan
Gi1/0/25 auto 802.1q trunking 1

My Problem is When I connect to the Port assigned to the vlan22 I dont not get IP
But when I configure manual I am able to ping the gateway of of the vlan22 which is on the 3850
I dont know what am doing wrong.

[brselzer]

Hello,

When you connect your laptop and give it a static IP. Can you ping all the way to the DHCP server? The DHCP server will need to have reachability all the way back to vlan 22. This is because the relay will encapsulate the discover in a unicast packet with a source IP of vlan 22. You could also try to ping the DHCP server from the 3850 sourced from vlan 22. (ping 192.168.200.96 source vlan 22).

If the ping fails, you will need to troubleshoot that connectivity. If the ping is successful, you might want to do a wireshark capture on the PC while it is trying to DHCP an IP to see where the process is failing. 

Hope that helps!