Few IP phones disconnecting frequently connected to extreme switch

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We have few IP phones connected to extreme switch , single port carries both voice and data vlan.

Both voip abd data have static it's.

All Ports are configured as tag for voice and untag for data.

Some pc's and printers are directly connected to switch ports (not through phones) and have static IP configured from data vlan.

Is there any possibility of above causing few phones to hang....?
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Sai Prasad Rao Rapolu

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Posted 2 years ago

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Henrique, Employee

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Hi, I don't see any issue with that environment. 

Is that just a confirmation or you are facing some issues with your phones?
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Sai Prasad Rao Rapolu

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Few specific phones are hanging/disconnecting from network.? From voip side everything is fine...


Is it not an issue if a port is configured as tag for voice and untag for data and someone directly connects a PC on that port with static data vlan IP.
(Edited)
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Henrique, Employee

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If you have a port tagged to a voice vlan and untagged to a data vlan and someone directly connects a printer to that port, all traffic will be forwarded through the data vlan.

I don't see any issue that could affect your phones.
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Sai Prasad Rao Rapolu

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What else could cause such an issue ..... no changes done on switches .....
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Henrique, Employee

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Few questions:

  1. Those phones hang and start working again without any action or you have to do something like a reboot?
  2. Is that always related to the same phones? Only those 4?
  3. When the phones hang, can you ping them? 
  4. Can you see the FDB entries during the issue?
  5. Does the PC still work when the phone hangs?
  6. Can you ping the PC when the phone hangs?
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Sai Prasad Rao Rapolu

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1: yes they automatically start working
2: yes same phones
3: all happens so fast , hangs and comes up, no chance of ping.
4: not checked
5: all happens so fast , hangs and comes up, no chance of ping.
6: all happens so fast , hangs and comes up, no chance of ping.
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Henrique, Employee

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Do you know if all phones hang at same time?
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Sai Prasad Rao Rapolu

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those phones are on different floors, it tough to answer that...
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Hagemann, Olaf, Employee

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Did you check the FDB in case a phone hangs? Is the MAC address of the phone still learned on that port? If the phone does not send any packet for a while, the MAC maybe aged out the FDB.
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Sai Prasad Rao Rapolu

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All phones are connected to same switch, 4 out of 30 phones are having issues. Why is Mac aging happening on specific ports
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Hagemann, Olaf, Employee

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MAC aging is happening on every port. It just depends on the end system. If some of the phones are not frequently used, they could age out. Just a guess.
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Sai Prasad Rao Rapolu

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Phones are on , connected 24/7. Could it be a physical cable issue or should I try to swap the phone on other port and check.
(Edited)
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Paul Russo, Alum

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Hey Sai

No issue with VoIP and data on the same port or having VoIP tagged.  That is the proper config.  I would move the phones to other ports, maybe ones that have phones that are connected and not seeing the issue.  If you swap them and it follows the phone then that should be a key indicator.  If it stays with the port then it can point to the cable.

You can also do a show port info on those ports and see if the up/down counters are going up showing a port disconnect or is it just the phones not responding.

P
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Sai Prasad Rao Rapolu

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makes sense 


cheers :-)
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Darin Seiler

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I have a similar issue with an active GTAC case open. GTAC has reviewed my DHCP bootprelay configuration and routing.

Environment: X450-G2 Summit with 16.1.3.6 code

Scenario: Data untagged, voice tagged. A Siemens Unify phone will randomly not obtain an IP from VLAN ID discovery through DHCP. Doesn't matter which switchport. We have 802.1x and MAC auth enabled. Disabling MAC authentication on the port seems to always allow the phone to complete its DHCP discovery process. When a phone does not pull an IP, the MAC is not learned in the voice vlan.

I have found 3 ways to get the phone to work in the meantime  1) Disable netlogin mac on the port 2) Run a disable port x followed by enable port x commands 3) Move the phone to a different switchport. 

Disabling inline-power to the switchport, physically unplugging the phone and plugging it back in, replacing the phone with a new phone, replacing the patch cable all have no affect. DHCP PCs (using untagged data vlan) using the phone's pass through work fine all of the time. 

We run the same configuration on many K-Series, S-Series, N-Series and have no issues with Unify phones.

 

(Edited)
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Leonardo Peixoto

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Hi Darin,

I'm having some issues with UNIFY IP Phones too...

Any news?

Best regards
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Darin Seiler

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We did a unconfigure switch all and then upgraded the firmware track to 22.x code and issue with mac auth and Unify phone went away