11-04-2017 04:01 AM - edited 03-08-2019 12:37 PM
I have a Cisco 4331 router that was configured with as a DHCP server for a small pool of Mitel iP Phones. The config of this router is a s follows:
ip dhcp excluded-address 172.20.2.139 172.20.2.142
!
ip dhcp pool Voice
network 172.20.2.128 255.255.255.240
default-router 172.20.2.142
domain-name xyz.com
option 43 ascii "id:ipphone.mitel.com;sw_tftp=10.104.0.2;10.103.0.2;call_srv=10.104.0.2;vlan=20;l2p=6v6s6;dscp=46v46s2"
!
!
The main LAN interface on the 4331 is setup as a dot1q trunk for VLAN’s 10 (Data) and 20 (Voice). The router makes a DHCP offer but the Mitel IP phone never accepts it, another DHCP request is then made by the IP Phone. The output of ‘show ip dhcp binding’ on the router shows the router offering the IP to be allocated e.g.
RTR01#sh ip dhcp bind
Bindings from all pools not associated with VRF:
IP address Client-ID/ Lease expiration Type State Interface
Hardware address/
User name
172.20.2.133 0108.000f.ba4c.30 Nov 02 2017 09:52 PM Automatic Selecting GigabitEthernet0/0/0.20
I move the same DHCP config to a Cisco 887 creating VLAN 10 and 20 and trunking them on Fa0 to the switch and it works fine.
The internal switch is a HP 2920 that is configured to trunk VLAN 10 and 20 back to the respective routers. The keyword ‘voice’ is configured VLAN 20 on the HP.
Using Wireshark (port mirrored from the phone directly) the only difference I can see in the DHCP offer between the 2 x router types is that on the 4331 Option 61 (Client - ID) is in the DHCP Offer reply to the IP Phone (the phone MAC).
In the 887 I don’t see option 61 in the DHCP Offer reply. Should this even matter.
I should have connected the 887 to the same port on the switch as the 4331 and re-tested but the VLAN trunking is the same on the separate ports back to the respective routers.
Can anyone offer an opinion. It’s driving me mad. Better still has anyone got a Cisco 4K config they can share that provides DHCP for a Mitel setup.
Many thanks for taking time to read.
Regards
Darren
11-04-2017 04:43 AM - edited 11-04-2017 04:45 AM
Hi @darreng
Not sure why it is necessary to add dscp on the dhcp option if you are not using QoS, but, I've seen others example where the option for dscp is dscp=46v46s26.
If possible, try to share both switches config so that maybe we can see something you're missing.
-If I helped you somehow, please, rate it as useful.-
11-05-2017 01:51 AM
Hi Flavio,
Thank you for taking the time to reply. Rather than send the whole switch and router config, I have summarised the key config snippets below. DHCP config is as per the original post on this router.
Port 1/1 on the HP switch stack that shows an IP phone plugged in. Other phones are plugged into the switch, the same config is repeated on those ports.
E.g. VLAN 10 (untagged) and VLAN 20 tagged towards the phone.
STACK-01# sh vlan port 1/1 de
15:19:59 Status and Counters - VLAN Information - for ports 1/1
Port name: Voice Port
VLAN ID Name | Status Voice Jumbo Mode
10 DATA | Port-based No No Untagged
20 VOICE | Port-based Yes No Tagged
STACK-01# sh cdp neigh de
CDP neighbors information
Port : 1/1
Device ID : 00 00 00 00 00
Address Type : UNKNOWN
Address : Unsupported format
Platform : MITEL 5320 IP,h/w rev 0,ASIC rev 1,f/w Boot 06.01.00.09,...
Capability : Switch
Device Port : LAN port
Version : MITEL 5320 IP,h/w rev 0,ASIC rev 1,f/w Boot 06.01.00.09,...
------------------------------------------------------------------------------
Port : 1/1
Device ID : SEP08000FBA5A70
Address Type : IP
Address : 192.168.1.10
Platform : M6020001
Capability :
Device Port : Port 1
Version : M6020001
VLAN 10 & 20 config, note the router is in port 1/48.
STACK-01# sh run vlan 10
Running configuration:
vlan 10
name "DATA"
tagged 1/48,4/48,Trk1-Trk2
untagged 1/1-1/44,2/1-2/44,3/1-3/43,4/1-4/44
no ip address
spanning-tree instance 1
exit
STACK-01# sh run vlan 20
Running configuration:
vlan 20
name "VOICE"
tagged 1/1-1/2,1/48,2/1-2/3,3/1-3/3,4/1-4/3,4/48
no ip address
voice
spanning-tree instance 1
exit
—————
Router configuration shows VLAN 10 and 20 trunked.
!
interface GigabitEthernet0/0/0.10
description Data VLAN
encapsulation dot1Q 10
ip address 10.1.219.252 255.255.254.0
no ip redirects
ip nat inside
standby 10 ip 10.1.219.254
standby 10 priority 105
standby 10 preempt delay minimum 25
standby 10 track 1 decrement 10
!
interface GigabitEthernet0/0/0.20
description VOICE VLAN
encapsulation dot1Q 20
ip address 172.20.2.140 255.255.255.240
no ip redirects
ip nat inside
standby 20 ip 172.20.2.142
standby 20 priority 105
standby 20 preempt delay minimum 25
standby 20 track 1 decrement 10
!
Regards
Darren
12-19-2018 09:59 AM
12-19-2018 11:13 AM
Hello
does access port include the both data/voice vlans
is a pc able to obtain dhcp address from the voice vlan scope
On the access port try
disable cdp
enable portfast
12-22-2018 03:26 AM - edited 12-22-2018 03:38 AM
Apologies for my delayed response to all those who replied. I haven’t been on the community forums for a while.
In the end we left the 887 providing the DHCP for the site in question. I’ll lab up the recommended changes above to see how things work out.
Thanks to to all for taking the time to reply.
Regards
Darren
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