1, problem description
IP phone receives S5700 POE switching equipment repeatedly, appear cannot electrify problem.
S5700 model: S5700-48TP-PWR-SI
IP phone model: Cisco 7911
Interface configuration:
#
Interface GigabitEthernet0/0/3
Undo Negotiation Auto
Description PC
Voice-vlan 4 Enable
Voice-vlan Legacy Enable
Port Hybrid Pvid Vlan 2
Port Hybrid Tagged Vlan 4
Port Hybrid Untagged Vlan 2
Stp Edged-port Enable
Port-security Enable
Port-security Max-mac-num 3
Trust 8021p
Trust Dscp
#
2, handle a process
1, affirm whether switching equipment supports POE. This switching equipment is POE switching equipment.
2, whether does examination IP phone have a problem. IP phone joins Cisco equipment can be used, the proof is no problem.
3, standard of examination POE power supply, investigate compatibility issue.
Affirm whether switching equipment can detect the compatibility between 802.3af and 802.3at standard. Below acquiescent circumstance, switching equipment won't detect this is characteristic.
Add a command
<PoE>System-View
[PoE] Int Gig 0/0/3
[PoE-GigabitEthernet0/0/3] Poe Legacy Enable
Ask the problem is solved
3, the root because
Cisco phone and China join to POE is passed between switching equipment, put in problem of compatibility of standard of POE power supply sometimes.
4, solution
Configuration
<PoE>System-View
[PoE] Int Gig 0/0/3
[PoE-GigabitEthernet0/0/3] Poe Legacy Enable
Command of Poe Legacy Enable is used make can PSE of power supply equipment detects to the compatibility of PD function.
