IP Phones stuck on detecting Network?

[JBrav0]

First things I have to explain why I an incompetent idiot is here asking this question. I work at a low budget community college and last month I was what most would consider a help desk or IT Level 1? I started studying Networking because I was interested. The start of this month is my first month in Networking because the last guy gave a sudden 2 weeks in and was the only Networking guy here. So now I'm here flying solo and trying my best, so sorry if I don't understand some things. 

With that said I really would appreciate any help. 

Recently a switch died and that lead to a certain user to lose connection, after changing the switch the phone would no longer register. It would stay at "Detecting network". I have no idea why, but thought it would have been short circuited due to being PoE. luckily it was on the list to replace since it was old. So I pulled out a an 8811 model Cisco Phone, went to CUCM and did what I had been doing for a while. The last guy left me a note that he would already have a template done for the new phones and all I would have to do is super copy that template and fill it out with the right extension and name as well as connect the users AD account. So far its worked on everyone's phone that I have done. 

After all had been done, I connect the new phone to the network and nothing. just stuck at detecting network. I tried 3 different phones (made sure to delete the other profiles). Nothing. maybe it was the switch so I took my office phone out and  plugged this new one in. Nothing. I manually went to the settings, turned DHCP off and copied all the settings from my working phones to it, with the exception of the IP address, I found one that wasn't reserved. Nothing. 

So at this point I'm at a loss. MAC address is good, no duplicates on extensions, MAC address or profiles. AD has been synching in just fine. 

What am I missing? or could be causing the issue? 

I also made sure things are in the correct VLAN's

[Roger Kallberg]

Initial guess would have been VLAN, but as you said it was checked out and was correct that’s likely not it. Have you checked the uplink from the new switch, is it configured the same as the old switch that you replaced? Maybe it doesn’t have the VLAN allowed to traverse the trunk? When you replaced the switch did you restore the configuration from the faulty switch on the new one?

Does the phone get a IP address when you connect it? If so do it get information on what TFTP server address to use?

Have you tried to reset the security settings on the phone?

[JBrav0]

The new switch is a Meraki switch, so configuring it was super easy. Even then I took it to my office where its entirely different switch with a working port. Since my VoIP Phone works, so I unplugged it and plugged the one that's having issues, nothing. I ran Wireshark and granted I don't know how to read the files as well, but there was only 3 things going on, and what stood out was DHCP was happening over and over as if it was trying to connect to it. Another thing that happened today was an already configured phone is also stuck in network detection mode after I applied a button update and hit applied config on CUCM. I want to say its a DHCP issue, even when I manually put the addresses in it has the same issue. Just not sure if that would be 100% accurate or makes sense. If so I don't even know where to start. 

[Adam Pawlowski]

You should be able to go to Settings -> Admin Settings -> Reset -> All Settings and reset the device.

You can look as well as the status messages in the Settings -> Admin Settings -> Status -> Status Messages to see what it is crying about before you do that, but I would think in most cases unless there's some specific network setting that's been keyed into the phone, you can reset the phone's settings and it should just slurp up what it needs.

[JBrav0]

So I did this and the status that it keeps giving is " Could not acquire IP address form DHCP" and "DHCP timeout". 

I tried doing a manual configuration and still had the same issue. We don't have a DHCP server on CUCM, but I have access to the server that does. I do see a 150 option for scope options as well. 

[Roger Kallberg]

Sounds like you don’t have a IP helper defined so that the request from the phone does not reach the DHCP server.

Using CUCM for DHCP is not recommended, so no issue that you don’t have it. It’s actually a good thing I would say.

[JBrav0]

Well I finally got it to reach the DHCP server, I came back after a while and checked the status on it, not sure how it got connected, but it did. However there is a new issue that the status displays "TFTP timeout" and "No trust list installed". I tried researching the question and all other things ive read just confused me or have me scared because I don't know much about CUCM and don't want to break anything. 

[Ratheesh Kumar]

Hi there

Can you also check if option 150 in the DHCP scopes.

Option 150 should be configured with all your TFTP servers (most of the cases the CUCM Pub)


Hope this Helps

Cheers
Rath!

***Please rate helpful posts and if applicable mark "Accept as a Solution"***

[JBrav0]

Yes, I see that option 150 has been configured in DHCP.

[Roger Kallberg]

Do you have anything in the network that filter what traffic is allowed to pass, like a firewall or an ACL? Sounds like your phone is not allowed to connect with your defined TFTP server or possibly as simple as the IP that is defined in the DHCP scope for option 150 simply is pointed to something that does run the CM TFTP service.

[Scott Leport]

Hi there, 

We've all been there at one stage in our career! I was also inclined to think VLAN, but it appears you've got that right. How many switches exist at site? Is it just the Meraki or does that uplink into a core / distribution switch? Have you got the appropriate VLANs allowed between the Meraki and any upstream switches?  

How is the DHCP pool looking on the DHCP server? Are there quite a lot of DHCP leases in place? What happens if you remove / delete a DHCP entry and connect the problem phone back into the network, does the issue still exist? 

Also has the 8811 phone previously worked? Was it previously registered to this CUCM or another CUCM? If it's the latter, then as Roger pointed out it would need the security certs cleared on the phone. 

[JBrav0]

In the area that I swapped it out with it has 4 switches all regular cisco switches. The Meraki uplinks to one switch that leads to the core switches. I do have the appropriate VLANS, actually when I connect a preconfigured phone it works, but when when I try with the phone that's giving me issues it wont do anything.  

I'm not extremely familiar with DHCP, but from what I gathered there is a set up and dedicated to VoIP's. I used Angry IP to scan the range and it seems that there are plenty of open IP addresses. 

This is a new 8811 phone, I was in the process of getting rid of the old ones and adding these around campus. No issue with the ones I've done, this is the first. I even tried 3 different new phones and still nothing. 

[JBrav0]

I ended up getting an IP from DHCP, but got a new issue where status message displays "TFTP timeout" and "No trust list installed". I tried researching the question and all other things I've read just confused me or have me scared because I don't know much about CUCM and don't want to break anything. 

[Scott Leport]

Hi there,

Have you tried connecting the new phone to a known working switch and port? Did you have the phone connected to another switch in another area to do the initial phone configuration and registration or did you just take the phone to the area where you have the problem? Can you take a known good working phone and patch it into the same switch and port where the problem phone is connected? Have you even tried another port on the Meraki switch?

If you have ruled all that out, can you try clearing the security certs of the problem phone please? To do this on an 8811 it is the following:

1. Apps Softkey (should be 3rd Softkey option, if not check your softkey template)

2. Select Admin Settings (4th option)

3. Select Reset Settings (4th option)

4. Select Security softkey (4th softkey)

5. Confirm the reset by selecting the reset softkey

If this doesn't work, do the same procedure, but in step 4 instead of selecting Security, select All. Adam has suggested that already, but I wasn't clear from other posts that you had tried that.

[JBrav0 · Accepted solution]

I figured out the issue. The CUCM Manager was up and running, but switch that was hooked up to it was dead. 

What was odd was that the publisher was running fine, but after running Cisco Unified Real Time Monitoring tool I noticed that the subscriber was down. I also later found out that the TFTP server was installed in the subscriber. So since the switch was dead do to a failure of a UPS it cased the phones to no be able to reach the TFTP file that it needed. After I got the switch up and running the subscriber was able to run through the network again giving the TFTP files that it needed. 

Thanks all for the help!