Dell EMC N1548 Switch stack and ShoreTel VoIP issues

Question

Hi all I've now spent hours trying to configure our Dell EMC N1548 Switch stack (sw ver. 6.5.1.3) to work with ShoreTel 230 handsets, so I'm hoping someone out there can help. Basically, handsets switch to the Voice VLAN,  but does not get an IP address from DHCP and goes into and endless reboot loop. Setup: Switch version: stack_1#show ver Switch version: Machine Description............... Dell EMC Networking Switch System Model ID................... N1548P Machine Type...................... Dell EMC Networking N1548P Serial Number..................... CN0MVV1J1111111R1111A00 Manufacturer...................... 0xbc00 Burned In MAC Address............. 1418.77F5.64B2 System Object ID.................. 1.3.6.1.4.1.674.10895.3066 SOC Version....................... BCM56150_A0 HW Version........................ 2 CPLD Version...................... 16 Image File........................ N1500v6.5.1.3 Software Capability............... Stack Limit = 4, VLAN Limit = 512 Our switches are fairly simple, in that we only have 2 VLANs: the Default (VLAN 1) and Voice (VLAN 2). We have global voice vlan enabled: switchport voice vlan Auto VoIP mode is not used: stack_1#show switchport voice gigabitethernet 2/0/19 Interface Auto VoIP Mode Traffic Class --------- -------------- ------------------ Gi2/0/19 Disabled 6 (all other ports are the same) IP Helper is configured globally and in the voice vlan: ip helper-address 192.168.32.51 dhcp ip helper-address 192.168.32.52 dhcp ... interface vlan 2 ip address 192.168.40.20 255.255.255.0 ip helper-address 192.168.32.51 dhcp ip helper-address 192.168.32.52 dhcp exit Port config: (note that vlan 1 untagged and pvid vlan 1 does not show in the config as these are default) switchport mode general switchport general allowed vlan add 2 tagged switchport voice vlan 2 DHCP is configured on Windows Server 2012r2 - each scope has this configured: (Data, Voice and TestData as mentioned below) Option 156 'IP Phone Boot Server' ftpservers=10.100.0.1, country=7, language=4, layer2tagging=1, vlanid=2 The phone model I'm testing is the ShoreTel 230 (various handsets tried)   LLDP is enabled as far as I can tell: stack_1#show lldp med LLDP MED Global Configuration Fast Start Repeat Count: .................... 3 Device Class ................................ Network Connectivity stack_1#show lldp med interface gigabitethernet 2/0/19 TLV Codes: 0- Capabilities, 1- Network Policy 2- Extended PSE, 3- Extended Pd Interface Link configMED operMED ConfigNotify TLVsTx --------- ------ --------- -------- ------------ ----------- Gi2/0/19 Up Enabled Enabled Disabled 0,1,2,3 Symptoms: The phone starts up, gets an IP in the VLAN1 range, then 'Reconfigures' (meaning it tries to switch to VLAN2) and then it just sits waiting for DHCP forever. I've noticed that the mac address table has two entries for this handset at this stage: stack_1#show mac address-table interface gigabitethernet 2/0/19 Aging time is 300 Sec Vlan Mac Address Type Port -------- --------------------- ----------- --------------------- 1 0010.4946.196E Dynamic Gi2/0/19 2 0010.4946.196E Dynamic Gi2/0/19 Attempts: At first I thought there might be an issue with the fact that we use the Default (1) vlan for data, so I creted another vlan (100), configured it to use the same ip-helpers and also created a new scope for the new VLAN. The new config looks like this for the switchport (which brings it in-line with Dell's documentation): stack_1#show running-config interface gi2/0/19 switchport mode general switchport general pvid 100 switchport general allowed vlan add 100 switchport general allowed vlan add 2 tagged switchport voice vlan 2 So, I reset the phone and tried again, but the same symptoms persist. The mac address table looks similar again (it gets an IP in vlan 100, then tries to switch to VLAN 2): stack_1#show mac address-table interface gigabitethernet 2/0/19 Aging time is 300 Sec Vlan Mac Address Type Port -------- --------------------- ----------- --------------------- 2 0010.4946.196E Dynamic Gi2/0/19 100 0010.4946.196E Dynamic Gi2/0/19   I've changed the port back to this:  switchport mode general switchport general allowed vlan add 2 tagged switchport voice vlan 2 Running Wireshark on the DHCP servers caught this (note that it does not have any packets since releasing the VLAN1 address): DHCP packet capture So please! I'm a bit stuck here and I'm being told 'You should have bought Cisco switches!' all the time, so I really need to get this fixed. Thanks

melcon · Answer

So, have you had any luck on fixing this or is it still an issue?   Best regards - MM

ixope · Answer

Same scenario here. A 4 member stack but with Cisco IP Phones.

Some random phones doesn't get IP address. Moving to another port within the same stack get's the phone up.

The recommendation from Dell's technical support, after a 6 month open case, was to dismantle the stack... No real reason behind this recomendation (bug, use case... nothing).

We have 8 stacks trough all the building. Managing each switch individually is far from what we expect at the moment of purchasing these.

We're very disappointed with Dell on this.

EDIT: I now realize that your entry is from 2018!!! We're at 2021 withe the same problem!!! So no changes in 3 years!!!

ingeflex · Answer

same issue. only works fine with firts 8 ports and lasts 8 ports.

DELL-Young E · Answer

Hello, thanks for choosing Dell. To me this sounds like you have some hardware issue. And as far as I know this might have a lifetime warranty. Could you please get in touch with our tech support team with an official ticket?  https://dell.to/3MKVrHl

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