Microsoft DHCP Issue

[neeper67]

I am having issues with implementing DHCP using Dell Powerconnect 6248P switches.

I have done the following:

1. Configured VLAN 2 (172.30.1.0)
2. Enabled Routing for both data (VLAN 1) and Voice (VLAN 2)
3. Enabled DHCP/BOOTP Relay
4. Enabled General mode for all the ports (trunking)
5. Enabled Tagging for all ports
6. I have ShoreGear on Access ports.
7. Implemented a new DHCP Scope for my VLAN 2 Phones.
8. Added Option 156 to both scopes with the string reading " ftpservers=172.30.1.6, layer2tagging=1, vlanid=2

I am able to ping between VLAN 1 and 2.
I am able to statically assign a phone with VLAN 2 configurations and it will function.
When using DHCP configured on the phone (after factory resetting it) it will obtain an ip address from my data scope and will reboot. Once rebooted the phone will not obtain an ip address from my voice scope. The phone will continue to look for a DHCP and eventually reboot once it gets to 300 seconds which it will continue to look.

I have tried many different variations of the string, but nothing seams to work.

If anyone needs it, I have uploaded my switch config. Please please feel free to ask any question about my situation, I will be happy to explain.

Here is more info about my switch:
Shore Gear: 2/g39, 2/g41, 2g/16
Voice Server: 2/g18
Testing phone port: 2/g21
DHCP server: 2/g13

[Mwilliams]

We initially had this issue on first setup. We thought we would make the new DHCP a custom. On the DHCP subnet make sure that 156 voip config - advanced tab -

1/ Vendor Class - DHCP Standard options
2/ User Class - Default User Class

[neeper67]

Hi, I was thinking of making the DHCP custom too, but I have not.

The settings are exactly how you stated for both of my option 156.

1/ Vendor Class - DHCP Standard options
2/ User Class - Default User Class

Please take a look at my screen shots of my scopes.

[aj1104]

Re:

On your network switches make sure that the port that your DHCP server is connected to is untagged member in the data vlan only. do not add it to the voice vlan or you will have problems pulling an address form the DHCP server.

AJ

[neeper67]

HI AJ,

Yes the DHCP server is untagged and is in the data vlan only.

[aj1104]

Re:

Neeper67

one thing that i see is that on your switches your gateway for the data vlan is 172.30.0.2 and in your dhcp scope it is 172.30.0.1. you need to change the router ip in your data dhcp scope to match the data vlan router gateway, also what port is your dhcp server connected to.

AJ

[neeper67]

Should I make the change even though my gateway firewall is 172.30.0.1? Then all computers will resolve to the switch the firewall which adds an extra hop. (just trying to get a good understanding, not doubting your intelligence)

My DHCP is located on port 2/g13

Shoretel Server: 2/g18
Shoregear: 2/g39, 2/g41, 2/g16

[aj1104]

Re:

Neeper67

On my switches which are extreme i point all traffic (voice and data) to the respective vlan gateway and the in the switch i defined the default gateway or internet gateway on my switch as my firewall ip address. Try changing in you dhcp scope and then reboot one of the phones and a pc and let them pull the new info and see what happens. As long as the other machine don't reboot the should retain the old info.and if it doenst work you can go back in and change it back. Make sure you add the default gateway in your switchgear.
Initailly i had the same issue until i pointed the dhcp router address to the respective vlan gateway


AJ

[shep]

I wound up with my data vlan untagged and my voice vlan untagged using 2 NICs in the server.

[neeper67]

I did make the change for my data scope to the 172.30.0.2 address, but the phone still continues to poll for DHCP on the "second boot"

[aj1104]

Re:

make sure that all of your SG switches are untagged in the voice vlan only.

[neeper67]

Shep, Does spanning tree ever shut down your ports?

[neeper67]

AJ, yes all the SG switches are exclusively in VLAN 2. (access mode)

[aj1104]

Re

Also make sure spannigntree is shutdown on any ports with SG swithes attached.

[aj1104]

spanning tree

this is some documentation that i pulled from shoretel support site

The following issues may be encountered when a ShoreGear switch is connected to an Ethernet port with Spanning Tree enabled:

ShoreGear IP Phones will fail to obtain an IP address from a DHCP server due to Spanning Tree blocking DHCP responses
ShoreGear switches can frequently lose connectivity to each other, as well as the ShoreWare Server
Delays in the establishment of the voice path for voice calls
Voice calls being dropped
Call control being delayed between Call manager and IP Phone
Voice calls not being able to connect
Poor quality of VoIP calls