Strange Issue in Campus Layer.

[reversearrow]

We are encountering very strange issue in our campus network. For example, the host is connected to Switch A - Port 20, everything is working fine. When we move the host to any other switch/port, the host doesn't get the IP address. We are running Layer3 at the campus layer so all vlans are locally significant. 

Here is a sample switch-port configuration: 

interface GigabitEthernet1/6
switchport access vlan 100
switchport mode access
switchport port-security
spanning-tree portfast edge
spanning-tree bpduguard enable

Cisco IOS Version:

Cisco IOS Software, IOS-XE Software, Catalyst 4500 L3 Switch  Software (cat4500es8-UNIVERSALK9-M), Version 03.08.00.E RELEASE SOFTWARE (fc2)

Cisco Switch Hardware:

NAME: "Switch System", DESCR: "Cisco Systems, Inc. WS-C4510R+E 10 slot switch "
PID: WS-C4510R+E

[Reza Sharifi]

Where is the gateway for vlan 100? 

What is topology look like?

[reversearrow]

Hi,

The gateway is on the switch iteslf, it is layer 3 switch (Campus Access Layer). Topology looks like this:L3 is on Campus Access Layer

[Reza Sharifi]

Hi,

If the gateway is on the access switches than you can't have the same vlan spanning multiple switches.  If you want to have vlan 100  on both switches, the access switches need to be layer-2 with a trunk connection between access and core and then the gateway is configured on the core.

HTH

[reversearrow]

Hi,

VLANs doesn't span multiple switches. 

[Reza Sharifi]

ok, but in your first post you said:

"For example, the host is connected to Switch A - Port 20, everything is working fine. When we move the host to any other switch/port, the host doesn't get the IP address.

So, does that mean when the host is connected to swtich-A port 20, it is in vlan 100 and when you connect it to say switch-B port 20 the vlan is different?

What is the vlan for switch-B?

Can you post the config?