02-13-2013 01:02 AM - edited 03-07-2019 11:41 AM
Hi,
I am configuring DHCP pool for voice vlan on cisco 2921 router.
Here is the setup.
2921 router -> 3750 -> 2960 PoE -> 7942 IP Phone
Router Config
ip dhcp excluded-address 10.146.54.1 10.146.89.50
!
ip dhcp pool VoiceVlan
network 10.146.54.0 255.255.255.0
subnet prefix-length 24
dns-server 10.144.68.32 10.144.68.33
option 150 ip 10.146.68.36
default-router 10.146.54.1
netbios-name-server 10.144.68.32 10.144.68.33
netbios-node-type h-node
domain-name wft.root.loc
lease 0 8
interface GigabitEthernet0/0
ip address 10.144.54.16 255.255.255.0
duplex full
speed 1000
!
interface GigabitEthernet0/0.50
encapsulation dot1Q 50
ip address 10.146.54.15 255.255.255.0
!
3750 Config
interface GigabitEthernet1/0/3
description To Router
switchport access vlan 54
switchport mode access
switchport voice vlan 50
speed 1000
duplex full
spanning-tree portfast
interface Vlan50
description VoiceVLAN
ip address 10.146.54.1 255.255.255.0
interface Vlan54
ip address 10.144.54.1 255.255.255.0
2960 Config
interface FastEthernet0/1
switchport access vlan 50
switchport mode access
spanning-tree portfast
!
Troubleshooting
Trunk is formed
2960#sh int tru
Port Mode Encapsulation Status Native vlan
Gi0/3 on 802.1q trunking 1
Port Vlans allowed on trunk
Gi0/3 1-4094
Port Vlans allowed and active in management domain
Gi0/3 1,50,54
Port Vlans in spanning tree forwarding state and not pruned
Gi0/3 1,50,54
Router received the dhcp discover from IP Phone, but it doesn't issue any IP. Here is the debug log
875525: Feb 13 15:11:26.167 GMT+8: IP: s=0.0.0.0 (GigabitEthernet0/0.50), d=255.255.255.255, len 576, input feature
875526: Feb 13 15:11:26.167 GMT+8: UDP src=68, dst=67, MCI Check(80), rtype 0, forus FALSE, sendself FALSE, mtu 0, fwdchk FALSE
875527: Feb 13 15:11:26.167 GMT+8: FIBipv4-packet-proc: route packet from GigabitEthernet0/0.50 src 0.0.0.0 dst 255.255.255.255
875528: Feb 13 15:11:26.167 GMT+8: FIBfwd-proc: Default:255.255.255.255/32 receive entry
875529: Feb 13 15:11:26.167 GMT+8: FIBipv4-packet-proc: packet routing failed
875530: Feb 13 15:11:26.167 GMT+8: IP: s=0.0.0.0 (GigabitEthernet0/0.50), d=255.255.255.255, len 576, rcvd 2
875531: Feb 13 15:11:26.167 GMT+8: UDP src=68, dst=67
875532: Feb 13 15:11:26.167 GMT+8: IP: s=0.0.0.0 (GigabitEthernet0/0.50), d=255.255.255.255, len 576, stop process pak for forus packet
875533: Feb 13 15:11:26.167 GMT+8: UDP src=68, dst=67
875534: Feb 13 15:11:26.167 GMT+8: DHCPD: client's VPN is .
875535: Feb 13 15:11:26.167 GMT+8: DHCPD: No option 125
875536: Feb 13 15:11:26.167 GMT+8: DHCPD: DHCPDISCOVER received from client 0110.bd18.0149.5b on interface GigabitEthernet0/0.50.
Any help is appreciated.
Cheers!
02-13-2013 03:51 AM
Will try to have a look once have some time but if you move this post to Network infrastructure > LAN switching and routing section you will get more feedback.
Terry
Sent from Cisco Technical Support iPad App
04-03-2015 10:39 AM
Dude, look at your DHCP exclude on your router.
It is supposed to be low/high IP.
So basicly you told the router to exclude IP address from 10.146.54.1 to 10.146.89.5.
This means that DHCP will not hand out 10.146.54.1 through 10.146.89.5
try
ip dhcp excluded-address 10.146.54.1 10.146.54.15
Hope this helps.
Also, I know this is years ago but thought I would throw that out there.
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