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PC's cannot connect through IP phones to network - If bypass IP phone, connect fine. Worked fine for 4 years until a power outage.

Experts, I need some help. Our VoIP system has been in place for about 4 years and we've never had any problems with it once it was implemented. Yesterday, we had a power outage and lost power to the building for about an hour so everything went down. This morning, any PC connected to the IP phone cannot connect to the network (getting an IP address but can't ping anything). If the PC bypasses the IP phone and connects to the network drop in the room, it connects to everything just fine. So it's almost like the Avaya IP phones are preventing the PC's from connecting to the network which I can't understand. We have two sites and the switches are all configured the same way. I checked the config on the switches at the site in question and it looks the same as it did 2 years ago (config hasn't changed). I'll attach the switch configs to the case. I have two Cisco 3750 switches (One is the main routing switch and the other is connected to it using the GBIC fiber connection).

The only thing I can think of is that the IP Phones when getting an IP address from our DHCP server is somehow not assigning the data to a different VLAN and therefore not routing correctly???

I also noticed that a few lab machines that are connected to a 100MB hub also can't connect to the network (and they aren't connected throuh phones). It's almost like anything connected to a phone or hub and then connected to the network can't connect to anything. If they are connected directly to the network drop, they can. Also, the IP Phones and voice network are working fine.

Thanks in advance for any help you can give. If there's any additional info, you need, let me know.
DHCP-Settings.docx
Routing-Switch.docx
Switch.docx

rochey2009

Hi,

From the cisco switch post,

show mac-address-table int fa1/0/x

for one of the ports connected to the an IP phone and PC.

Does it list the mac address of the phone and the PC on their correct VLANs?

Can you ping the PC from the switch?

iwaxx

Hi,

Like rochey2009, I would ping the pc from the switch plus:

* Do PC get the router IP in their DHCP lease ? (10.3.110.254)
* Can they ping their router ?
* Can two PCs on the same switch and behind IP Phones can ping each other ?
-> You must start to narrow down the problem to find if it's a Layer 3 issue with your router, or a Layer 2 and point out at which level : on switch port, between the two switches ...

vianceadmin

ASKER

Cannot ping the PC from the switch.

Yes, when I do a show mac-address-table it shows both network ports (PC and phone) in the correct vlan's...

Yes, PC's get the correct router in their lease...

Seems like anything that is connected to some sort of hub (linksys hub, IP phone, etc.) cannot connect to the network...What in the switch could cause that?

iwaxx

* Can two PCs on the same switch and behind IP Phones can ping each other ?

vianceadmin

ASKER

Problem is not isolated to just IP phones...Seems like other PC's that are connected through a 4 port hub for example can also not connect (cannot ping anything locally). Two printers that are connected through a 4 port hub can only connect locally, not across the gateway (10.3.110.254).

* Can two PCs on the same switch and behind IP Phones can ping each other? No, they cannot ping each other.

iwaxx

It may comes from a vlan stuff, or a mishandling of ARP from the switch, or a port security issue (which would allow only one device behind its port).

Try "show port-security interface fastethernet 1/0/x" to see the status of the port security.

Can you send us some details of the situation with two pc behind ip phones on the same switch:

* show mac-address-table int fa1/0/x of the two ports
* show interfaces fastethernet 1/0/x of the two ports
* show vlan
* Ipconfig /all of the two pc
* ip address of the two ip phones

Have you tried to take a packet capture ?
You may see interesting answer like an ICMP reply explaining the failure

ASKER CERTIFIED SOLUTION

vianceadmin

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vianceadmin

ASKER

Issue was with an incorrectly configured switch.