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Cisco 7940 IP Phones are taking the IP address from Data Vlan

Hi,

I have 300 Cisco IP Phones (7940G) in which only around 40-50 Phones are taking the ip address from Data Vlan ip address range, rest all the ip phones are taking from the voice vlan ip address range.

I have windows 2003 DHCP Server in which Data Vlan & Voice Vlan is created each having 512 IP Address, both have sufficient free IP Address.

Ip Helper address command is fine and all the ports are added to voice vlan. Everything was fine but now i am facing this problem like some phones are taking the IP Address from Data Vlan.

Can somebody pls let me know how to rectify it.
Voice Over IPDHCPWindows Server 2003

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8/22/2022 - Mon
Slawomir Malinowski

Could you post a command "sh int switchport"?
ASKER
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Name: Fa4/19
Switchport: Enabled
Administrative Mode: static access
Operational Mode: static access
Administrative Trunking Encapsulation: negotiate
Operational Trunking Encapsulation: native
Negotiation of Trunking: Off
Access Mode VLAN: 15 (user)
Trunking Native Mode VLAN: 1 (default)
Administrative Native VLAN tagging: enabled
Voice VLAN: 16 (voice)
Administrative private-vlan host-association: none
Administrative private-vlan mapping: none
Administrative private-vlan trunk native VLAN: none
Administrative private-vlan trunk Native VLAN tagging: enabled
Administrative private-vlan trunk encapsulation: dot1q
Administrative private-vlan trunk normal VLANs: none
Administrative private-vlan trunk associations: none
Administrative private-vlan trunk mappings: none
Operational private-vlan: none
Trunking VLANs Enabled: ALL
Pruning VLANs Enabled: 2-1001
Capture Mode Disabled
Capture VLANs Allowed: ALL

Unknown unicast blocked: disabled
Unknown multicast blocked: disabled
Appliance trust: none

Name: Fa4/20
Switchport: Enabled
Administrative Mode: static access
Operational Mode: static access
Administrative Trunking Encapsulation: negotiate
Operational Trunking Encapsulation: native
Negotiation of Trunking: Off
Access Mode VLAN: 15 (user)
Trunking Native Mode VLAN: 1 (default)
Administrative Native VLAN tagging: enabled
Voice VLAN: 16 (voice)
Administrative private-vlan host-association: none
Administrative private-vlan mapping: none
Administrative private-vlan trunk native VLAN: none
Administrative private-vlan trunk Native VLAN tagging: enabled
Administrative private-vlan trunk encapsulation: dot1q
Administrative private-vlan trunk normal VLANs: none
Administrative private-vlan trunk associations: none
Administrative private-vlan trunk mappings: none
Operational private-vlan: none
Trunking VLANs Enabled: ALL
Pruning VLANs Enabled: 2-1001
Capture Mode Disabled
Capture VLANs Allowed: ALL

Unknown unicast blocked: disabled
Unknown multicast blocked: disabled
Appliance trust: none

Name: Fa4/21
Switchport: Enabled
Administrative Mode: static access
Operational Mode: static access
Administrative Trunking Encapsulation: negotiate
Operational Trunking Encapsulation: native
Negotiation of Trunking: Off
Access Mode VLAN: 15 (user)
Trunking Native Mode VLAN: 1 (default)
Administrative Native VLAN tagging: enabled
Voice VLAN: 16 (voice)
Administrative private-vlan host-association: none
Administrative private-vlan mapping: none
Administrative private-vlan trunk native VLAN: none
Administrative private-vlan trunk Native VLAN tagging: enabled
Administrative private-vlan trunk encapsulation: dot1q
Administrative private-vlan trunk normal VLANs: none
Administrative private-vlan trunk associations: none
Administrative private-vlan trunk mappings: none
Operational private-vlan: none
Trunking VLANs Enabled: ALL
Pruning VLANs Enabled: 2-1001
Capture Mode Disabled
Capture VLANs Allowed: ALL

Unknown unicast blocked: disabled
Unknown multicast blocked: disabled
Appliance trust: none
Slawomir Malinowski

Config looks fine.
What is your phone firmware version.
Below 7.3 is a bug with dhcp.
"The phone accepts a DHCP offer from the data VLAN and tries to communicate on the voice VLAN with this IP".
Your help has saved me hundreds of hours of internet surfing.
fblack61
ASKER
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Hi.
Sorry for the late response, i was on leave

In Settings Status
Firmware Versions
1) App Load ID - P00308000700
2) Boot Load ID - PC0303010200
3) Version - 8.0(7.0)
4) Expansion Module 1
5) Expansion Module 2
6) DSP - 4.0(4.0)[A0]

i am seeing these but the firmware version as u mentioned is 8.0 and in brackets it shows as 7.0
Pls let me know what to do.
Slawomir Malinowski

Your firmware is ok.
Please check the link below - it should help.
http://www.cisco.com/en/US/products/sw/voicesw/ps556/products_tech_note09186a008055c1fe.shtm
ASKER
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No that link is not available now
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Slawomir Malinowski

ASKER
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this tftp option has been already, this is fine from our part.
Slawomir Malinowski

What about cdp configuration?
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William Peck
ASKER
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CDP is disabled
ASKER CERTIFIED SOLUTION
Slawomir Malinowski

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ASKER
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Yeh Thanks,

I enabled the cdp and it started working . Thanks a lot.