Solved DHCP

[Joe A]

Hi,
I am having a weird issue with a new setup.

I just setup 3CX hosted by 3CX.
as I am adding phones onto the network, I don't have option 66 in the router (Hitron cable modem/router) so I am logging into the phone and adding the provisioning url.
it has been working fine, until I add the 5th phone.

the phone gets DHCP and then after 20 seconds it drops its network config. I ordered another phone and it is doing the same

the phones are connected to:
GS324TP S350 Series 24-Port Gigabit Ethernet PoE+ Smart Managed Pro Switch with 2 SFP Ports (190W)
under factory settings

I logged into the Hitron router and disabled SIP ALG

the phone reports an error:
Error: ipv4 ip obtain failed
Error: Vlan id: 1

The other 4 phones work fine. I just can't add anything more than that to the network

Any suggestions?

Thanks
Joe

 

[Evolute IT]

Running out of IPs? How big is the pool and how many devices are there already?

Are there any static IPs on the network that could cause conflicts?

 

[Joe A]

I have a block of 100 IP's and only a dozen items on the network

I have tried assigning a static ip to the phone (through reservation) and it works for 20 seconds
That is the only reservation in DHCP

 

[leejor]

How many IP's is the router set to allow for DHCP? Most have a limit preset, perhaps you've reached that..

 

[Joe A]

there is a post online about disabling the vlan option in the phone. I haven't tried that yet.
The Netgear .GS324TP is factory default. shouldn't be messing with DHCP. and there is only 1 VLAN, id#1 that is the default for all traffic
I am leaning towards the router, but there are no advanced setting in DHCP

maybe UPnP, I turned off SIP ALG

 

[JohnS_3CX]

Hi Joe,

Since you are using a smart switch, there's always the possibility that a misconfiguration could cause issues.
I would start by factory-defaulting the switch and ensure its not doing anything funny (ie. it acts as a plain old switch)

Then I would reboot the HITRON device (assuming it's the one running DHCP here) and connect only the switch to it and absolutely nothing else.

Now that you have an isolated network, you can log into the HITRON and see its DHCP client list, which should in theory be empty.

Finally, you may start connecting phones one by one and observe the results.
By the way you haven't mentioned what phone models you are connecting, or what firmware version they are running..

 

[Joe A]

I got it fixed last night.
I had to set a static IP on the phone, then I logged into the phone from the webgui

Disabled the DHCP VLAN, LLDP Settings and the Cisco Discovery (CDP) settings (see attached)
It is now staying on and I was able to provision the phone (yeah!)

I don't know which one of the settings is causing this to happen and why on the 5th phone.

If I need to add more phones, I might have to disable the DHCP services on the Hitron and set it up on the switch instead. Probably a better way to do it as the switch will give me DHCP options that the Hitron won't

-Joe

 

[JohnS_3CX]

Hi Joe,

Glad to hear you got your phones back online! If you need any further assistance in the future feel free to start a new thread.