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After Enabling trunking and two VLANs on switchports - clients don't receive IP Addresses

pendal8286
Level 1
Level 1

Hello all and thanks for your help and expertise.  Here's my scenario:  

I have approximately 35 Ruckus APs in a building which has multiple VLANs.   The switches are Cisco 3560G.  I want to segment the wireless traffic onto a dedicated wireless VLAN (218).  I created two scopes in DHCP to service the APs and wireless clients. The APs should get their IP addresses on VLAN 1 (VLAN 1 scope in dhcp.)   The clients should get their IP addresses on VLAN 218 (VLAN 218 scope in dhcp).  I utilized the following commands to accomplish this goal, unsuccessfully.

Example:  on port gi0/5

1 - switchport trunk encapsulation dot1q

2 - switchport mode trunk

3 - switchport mode access

4 - switchport trunk allowed vlan 1,218

 

Problems:  1) The APs are not getting an IP address on the default or native VLAN 1 unless I configure an IP Helper.  Please note we have another building where a consultant set this configuration up (and it works) but I don't see an IP helper set when I check the config for VLAN 1.  

2) The wireless clients do not get an IP address on VLAN 218, even if I set an IP helper address.  In the other building - there is an IP helper set on VLAN 218 so I'm not sure what I missing or if something else is configured.  

I would greatly, greatly appreciate if someone could tell me what I'm missing here.  Is there something else I have to do to ensure clients on vlan 1 and 218 are able to obtain dhcp addresses in the config of the switch?  Do I have to further configure vlan 1 or 218?  I'm enabling the correct encapsulation, trunking the ports, and setting the vlans.  What am I missing here relative to APs and clients getting dhcp addresses.  Anyway your help is much apprecaited.

 

 

 

 

8 Replies 8

johnd2310
Level 8
Level 8

 

Where is the DHCP server? If the DHCP server is on the same subnet as the client, then you do not need the ip helper(could be why the other building is working without ip helper). If DHCP server is on a different subnet to client, you need ip helper.

What is the output of 'show interface gi0/5 trunk'? Is the port in trunking mode? If not, it would explain why the wireless clients are not getting an ip address.

 

Thanks

John

 

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The dhcp server is on a different subnet.  There are multiple vlans in this building.   I'll double check the status of the port and post here soon.  Thanks. 

The port is trunked.  Clients still can't get IP addresses on vlan 218.

I'm not familiar with Ruckus but did you configure the APs to use dot1q trunks and put the clients on vlan 218?

Yes.  The config on the Ruckus controller is configured correct.  That was the easy part.

Question:  Do you have to add vlan 218 into the spanning tree on the core switch and all the uplinks?

You need vlan 218 on all switches and allowed on all trunks that need to pass traffic for that vlan.

You don't have to add it explicitly to STP as it should be run anyway but if you manually set STP priorities for other vlans you should probably do if for this vlan as well.

Shouldn't stop it working though.

If you manually assign a vlan 218 IP to a client can it ping the SVI IP ie. it's default gateway and if so can it ping devices in other vlans ?

Jon

Jon,

 

Yes, vlan 218 is allowed on all trunks.  

However, when we manually configure a device with the vlan 218 scope - we are unable to ping the vlan 218 gateway.  This is so frustrating.  Everything seems right.

Can the AP ping it's default gateway ?

Can you post a "sh int trunk" for any port connected to an AP ?

In addition are the SVIs on the 3560G or are they are another switch ?

Jon

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