Phone Booting to a VLAN

[paul3461000]

I am just wondering how a phone boots up when there's a VLAN.

Does the phone boot, pull down the 46xxsettings.txt file, read the "SET L2QVLAN 2" then reboot to the new VLAN?

Does it do repeat the process in all future boots or is the new VLAN informaion stored on the phone and used until the 46xxsettings.txt file is differnt than the current setting?

Do I have it right?

 

[kwing112000]

I usually use the 176 option in the DHCP server. I would add a string into the data scope with the VLAN number in it and when the phone boots it gets that 176 string. then it reboots with the correct VLAN number and pulls all of its info.

Kevin Wing
ACA- Implement IP Office
Carousel Industries

 

[tlpeter]

Set it in the dhcp server

Make an option 176 and put in this:

L2Q=1,L2QVLAN=xxx,PHY2VLAN=yyy

Then you make a new scope
In this scope again make option 176
put in this:

MCIPADD=xxx.xxx.xxx.xxx,MCPORT=yyyy,TFTPSRVR=zzz.zzz.zzz.zzz

In this case your dhcp server must have two nics or you need two routers !!!


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[paul3461000]

Kevin,

Could I get you to post your Option 176 string?

I can't seem to find the syntax needed for the VLAN even though I've been all over the 4600_lan_admin.pdf guide.

 

[tlpeter]

Paul, i already did that


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ACS - Implement IP Office
ACA - Voice Services Management
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Women and cats can do as they please and men and dogs should relax and get used to the idea!

 

[kwing112000]

Peter,
You can do that with one nic and one router. we do it all the time. youhave to set the port on the network switch for untagged in the data VLAN and it will work.

Kevin Wing
ACA- Implement IP Office
Carousel Industries

 

[tlpeter]

Good to know that
I normaly never do the network part so i do not know those things


ACA - Implement IP Office
ACS - Implement IP Office
ACA - Voice Services Management
______________
Women and cats can do as they please and men and dogs should relax and get used to the idea!

 

[paul3461000]

I am using 3750 siwtches and I believe the native VLAN on the data side is untagged by default (that's why it is the native VLAN)

Just trying to wrap my head around this.

When the phone boots it will send broadcast out requsting an IP address from a DHCP server. The first time it will broadcast untagged on the data vlan because the phone is set not use a vlan. DHCP server answers with an IP address in the data lan but also tells the phone to go to VLAN2 via option 176. The phone now has an invalid IP address for VLAN2.

What am I missing here? Does the phone then send out another DHCPREQUEST on the tagged VLAN and get the proper ip address?

 

[kwing112000]

yes the phone sends out a new request saying i am in VLAN 2 give me the right address. you may need DHCP helpers in the cisco for this to happen. you should have a second DHCP scope for VLAN 2.

Kevin Wing
ACA- Implement IP Office
Carousel Industries

 

[kurthansen]

Also be sure to have the DHCP server only on the native vlan and no access to the voice vlan. What happens is the server will try to respond to the voice vlan and still give it a native vlan IP address when the device was requesting a IP on the voice vlan.

 

[paul3461000]

To all who posted, thanks for the excellent information.

By the way I did find the VLAN DHCP settings in the 4600_lan_admin guide. I just had to find a new version of the document, it wasn't in the 2004 version I was looking at.