Symptoms:

• Router detects duplicate IP address
• Duplicated IP address reported on the 3103 phone LCD
• No audio on Layer 3 calls
• No Audio on VTL calls
• Need to understand how NCP assign ip address from IP pool when IP on Fly (IPoF) is used
• IP address conflicts
• Duplicated ip address reported by Layer 3 switch

Facts:

• SuperStack 3 NBX V5000 Call Processor
• SuperStack 3 NBX V5000 Chassis
• NBX 100
• NBX V3001R
• 3Com NBX V3000
• NBX R5_0
• NBX R6_0
• BX R4_4
• NBX R4_3
• NBX R4_2
• NBX R4_1
• NBX R4_0

Causes: NBX Code version 5 or early does not support Round Robin method when assign IP address using IPoF

Fixes: Upgrade to NBX code version 6

Notes: Under code version 5.x.x and early, NCP will assign IP address to devices as First in First out. For example, NBX using IP range from 10.1.1.100 to 10.1.1.200, if there is only one layer 3 calll at a time, the device will receive IP 10.1.1.200 each time.

This may cause Layer 3 network device to detect duplicate IP address or ARP conflict.lt;o:p>

Under version 6.x.x, NCP will assign IP address to devices using Round Robin method. For example, NBX has IP address range from 10.1.1.100 to 10.1.1.200, if there is only one layer 3 call at a time, the device will receive different IP each time, eg. 10.1.1.200, 10.1.1.199, 10.1.1.198 etc.

• Product(s): NBX
• Sub Product(s): NBX 100, SuperStack 3 NBX, 3Com NBX V3000

— David Gonzalez 2021/04/13 11:01