Voice network help - Boot process.

Guys, Im really scratching my head on this one. where to begin.. ok...

I have my voice lab setup and my phones are stuck @ configuring IP which tells me one simple thing, no communication with the dhcp server. Interesting enough, my laptop grabs an ip address just fine. attached is a sample of my voice network. the sample shows the pc connected to the phone, but in my case, the pc is connected to port 3 on the switch.

I am not sure if i am missing something but if someone can assist, i would be grateful.

Thank you.

DHCP router is setup for both voice/data pools.

interface FastEthernet0/0
ip address 172.16.2.5 255.255.255.0
duplex auto
speed auto

ip dhcp excluded-address 172.16.1.1 172.16.1.10
ip dhcp excluded-address 172.16.2.1 172.16.2.10
!
ip dhcp pool voice
network 172.16.1.0 255.255.255.0
default-router 172.16.1.1
option 150 ip 172.16.1.1
dns-server 4.2.2.2
!
ip dhcp pool data
network 172.16.2.0 255.255.255.0
default-router 172.16.2.1
dns-server 4.2.2.2

CME router it setup for router-on-stick

interface FastEthernet0/0
no ip address
duplex auto
speed auto
!
interface FastEthernet0/0.10
encapsulation dot1Q 10
ip address 172.16.1.1 255.255.255.0
ip helper-address 172.16.2.5
!
interface FastEthernet0/0.50
encapsulation dot1Q 50
ip address 172.16.2.1 255.255.255.0

Switch A port 1 setup for VLAN 50 (to dhcp)
Switch A port 23 setup for Trunk (t0 cme)
Switch A port 24 setup for Trunk (to switch

interface FastEthernet0/1
switchport access vlan 50
switchport mode access
spanning-tree portfast

interface FastEthernet0/23
switchport mode trunk
!
interface FastEthernet0/24
switchport mode trunk

Switch B port 24 setup for Trunk (to switch A)
Switch B port 1 setup for Voice vlan 10 and access vlan 50
Switch B port 2 setup for Voice vlan 10 and access vlan 50
Switch B port 3 setup for Voice vlan 10 and access vlan 50

7940 IP phone connected to port 1 and 2, Laptop connected to port 3.

interface FastEthernet0/1
switchport access vlan 50
switchport mode access
spanning-tree portfast
!
interface FastEthernet0/2
switchport access vlan 50
switchport voice vlan 10
spanning-tree portfast
!
interface FastEthernet0/3
switchport access vlan 50
switchport voice vlan 10
spanning-tree portfast

Voice.jpg

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Comments

wastedtime

Not completely sure but I would say try to do a factory reset on the phone, and make sure CDP is enabled on the switch.

Resetting 7900 Series IP Phones to Factory Defaults [Cisco Unified IP Phones 7900 Series] - Cisco Systems

This has a bullet point under "Voice VLAN Configuration Guidelines" about CDP
Catalyst 2970 Switch Software Configuration Guide, 12.1(14)EA1 - Configuring Voice VLAN [Cisco Catalyst 2970 Series Switches] - Cisco Systems

tokhss

I already reset the phone to factory on both and also made sure CDP was enabled on both switches. when i do a sh cdp, i can clearly see the ip phones

i can also ping the CME router from the dhcp server on both sub interfaces and so forth from the CME router to the dhcp router.

the only thing i can think of is wiping out everything on all hardware and starting from scratch, with a clear config.

wastedtime

I think it just hit me. You have dhcp on 1 router and cme on the other but you are using the "ip helper-address" on the cme router. I believe I ran into this problem before. You need "service dhcp" on the cme router as it will not do dhcp relay without the dhcp service running.

tokhss

I will def give that a try first thing tomm night as i am about to knock out (to bes honest, the equipment is shutdown)..lol.. in the meantime, just to test my equipment, i hooked up my UC520W and setup some vlans and bam, it worked. I really didnt want to get my UC520 out and configed yet as i wanted to learn by the book first. Ah well, at least i know my phones are fine.

again, once i get time to throw that line on the CME router i will respond back and let you know.. thanks!

laidbackfreak

This is also incorrect :-

interface FastEthernet0/1
switchport access vlan 50
switchport mode access
spanning-tree portfast
!
interface FastEthernet0/2
switchport access vlan 50
switchport voice vlan 10
spanning-tree portfast

fa0/1 is missing the voice vlan and fa0/2 and fa0/3 are missing the mode command.

tokhss

good catch... i have redone my config so many times that its not a shocker to see things missing now.. im in a drowsy state lol.. nevertheless, i will report back tomm night

im gonna kick myself if its something stupid i didnt put in..

darkerosxx

Also, check your phones to see if the network settings are admin-locked. I got a set of phones that were admin-locked and had to look up the unlock codes. Until I had those codes, a factory reset didn't actually do anything.

tokhss

Well, NO luck with command "service dhcp" on the cme router. whats throws me off is that the PC grabs an ip but the phones dont, at least in this physical configuration. If i connect my phones to the UC520W then my config works just fine.

I seriously think i need to wipe out my config on everything and start over, unless i need to add something to the config that i am not aware about.

what i know and can do so far with the dual router + 2 switch configuration...

1. DHCP router is able to ping CME router on both sub interfaces
2. CME router is able to ping FA0/0 interface on DHCP router.
3. PC connected to switch B is able to pull a DHCP IP of 172.16.2.11 and ping all interfaces.
4. IP phones on vpice vlan 10 wait for ip address.

Swtich B = 3524 power
Switch A = 2960 XL

laidbackfreak

If I get a chance I'll try to lab this up later today see if I can recreate the problem.

For now though, chuck the dhcp config onto the CME and see if that works ?

tokhss

yeah.. im about to knock out again.. my study time is roughly 2 hrs worth everynight if i get a chance.. lol.. but i will try that and report back sometime tonight since its 2 am right now lol.

CME = 2650XM

darkerosxx

Did you check to ensure your phones weren't locked? I had the exact same situation... my laptop would get an IP, two other phones would get IPs, but not the phones that were locked.

tokhss

The phones are not locked as they get IPs when connected to the UC520 ... the only time they do not get IPs is when they are connected in the configuration that i provided above.

darkerosxx

Ok, well yeah, after you get the changes mentioned previously done, if it's still not working, copy/paste your full configs so we can have a look.

tokhss

well, i found the problem. however, i dont understand why this is happening.

i simply removed "access vlan 50" on a single port from the 3524 switch as a test and bam, the ip phone got an address.

so wtf? lol seems that if i keep the port config simple, the phone gets an ip, but if i add the data vlan to it, then the problem comes about.

tokhss

in the meantime, i am using my UC520 as my curriculum platform. so far so good, i can make calls between phones, however, i dont have a phone line to a pstn nor do i have a itsp account. lol..

darkerosxx

Glad you got it working. You should be able to keep that statement there and have it working, though. Without seeing your configs, I don't think we'll be much help.

I'm using a UC520, also, for my CCNA:V studies. Are you getting into the IOS or just doing stuff with the Cisco Configuration Assistant?

tokhss

CLI only until the end of the book where its required to know the CCA. i must say tho, all the fun was setting up the network and making a call. the rest is pretty damn boring in regards to features, forwarding, groups, parking, etc.. im dragging my feet in this area..