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no ethernet connection IP Phone

nabeel92 used Ask the Experts™
Hi there,
There is a PC connected to an IP phone. PC works fine, IP phone says "no ethernet connection". I've checked the configuration on switchport for access/voice vlan which is ok. any pointers what can be the issue ? Last time I had an issue like this, it was related to incorrect switchport configuration but config looks ok !

interface GigabitEthernet0/x
 description IPPhone+PC Port
 switchport access vlan 14
 switchport mode access
 switchport voice vlan 114
 switchport port-security maximum 2
 switchport port-security
 switchport port-security aging time 5
 switchport port-security violation restrict
 no logging event link-status
 speed auto 10 100
 priority-queue out
 mls qos vlan-based
 no snmp trap link-status
 storm-control broadcast level 0.10
 spanning-tree portfast
 spanning-tree bpduguard enable
 spanning-tree guard root

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Steve JenningsSr Manager Cloud Networking Ops

. . . maybe PC is trying to negotiate 100 and phone is trying to negotiate 10? Honestly never played much with patching phone through pc or vice versa. But it seems like "auto" isn't a good idea. Also, just for grins take out the switchport port-security or make it 3 . . . don't the phones have a mini-hub that might be throwing out a 3rd mac?

Good luck,

Has the phone been programmed to use VLAN 114 or should it be pulling its settings down from a DHCP server option?

Also, maybe try it without the "speed auto 10 100" line.  Most IP phones are 100, but maybe the phone wants to auto-negotiate.


Yes. I changed the phone's duplex settings to full and auto-negotiate as well. The switch ports are configured for speed 10 100 and IP phones are set to auto negotiate for all other IP phones. Making port-security maximum 3 might be a good idea but am not sure if it displays "ethernet disconnected" on IP phone if port-security max. is violated, not sure on that ?
PC works fine directly on that wall jack, phone doesn't. No phone works on that Wall Jack. I think I'll have somebody repunch the connections in that Wall jack and increase port security maximum to 3.
If all else fails, you can try removing all the port-security settings.  But if that config is working on other ports with the same model of ip phone then yeah, it may be an issue with the jack


it was the wall jack ... whose connection needed to be punched .. interstingly, all pc worked in that but none of the phone would ... so am sure the phone would use different pins ... all sorted, thanks guyz !