[cisco-voip] Switch Hanging off Phone

[Mike Brooks]

Do you have the logs from the switch for around that time ?

thx,

Mike Brooks
CCIE# 16027 (R&S)

On Sat, Sep 20, 2008 at 4:54 PM, Todd Franklin <toddnh65 at gmail.com> wrote:
> no, not plugged back into the walljack.
>
> But the whole phone setup went wild yesterday around 6PM, and he "moved the
> network equipment on my desk around" around 6PM yesterday.  Sure seems a
> likely culprit!
>
> On Sat, Sep 20, 2008 at 2:58 PM, Matlock, Kenneth L <MatlockK at exempla.org>
> wrote:
>>
>> Are you sure that one of the ports off the linksys wasn't 'accidentally'
>> plugged back into a wall jack (and essentially into the upstream switch)?
>>
>> Very easy to bridge 2 VLANs doing that, and that will almost definitely
>> affect one (or both) of them.
>>
>> What VLAN is used for the data traffic? I believe by default most 'switch'
>> gear uses VLAN 1 by default, and if it was spitting out STP or VTP data,
>> that could cause serious issues, depending on your topology.
>>
>> Ken Matlock
>> matlockk at exempla.org
>> (303) 467-4671
>> Network Analyst
>> Exempla Healthcare
>>
>> ________________________________
>>
>> From: cisco-voip-bounces at puck.nether.net on behalf of Todd Franklin
>> Sent: Sat 9/20/2008 1:47 PM
>> To: Mike Brooks
>> Cc: cisco-voip at puck.nether.net
>> Subject: Re: [cisco-voip] Switch Hanging off Phone
>>
>>
>> Thanks Mike.  The config of the switchport:
>>
>> interface FastEthernet0/4
>>  switchport trunk encapsulation dot1q
>>  switchport mode dynamic desirable
>>  switchport voice vlan 6
>>  srr-queue bandwidth share 10 10 60 20
>>  srr-queue bandwidth shape  10  0  0  0
>>  mls qos trust device cisco-phone
>>  mls qos trust cos
>>  auto qos voip cisco-phone
>>  spanning-tree portfast
>>
>> It really screwed around with the phones.  The data stayed ok.
>>
>> He came off from the switchport, into the 7940.  From there into the
>> Linksys (which has a built in 4 port switch) and one of those ports he had
>> plugged into his PC.
>>
>> What do you think?
>>
>> Todd
>>
>>
>> On Sat, Sep 20, 2008 at 3:38 PM, Mike Brooks <2xccie2b at gmail.com> wrote:
>>
>>
>>        What was the configuration of the switchport ?  Also was the data
>> vlan
>>        affected at all or just devices on the voice vlan ?  A common issue
>> we
>>        have seen with hubs plugged in is them getting mis-cabled by the
>>        enduser and getting looped up causing major issues on the network.
>>  I
>>        do not believe the linksys devices send BPDUs.  If it was a cabling
>>        issue on the linksys ..then enabling bpduguard on the port will
>>        errdisable the port..because the port will receive its own bpdu if
>> the
>>        linksys is miscabled.
>>
>>        Also, the linksys could have been acting as a rouge dhcp server.
>>  Not
>>        knowing how your network is set up or the symptoms you were
>>        experiencing it would be hard to tell.
>>
>>        Just a few guesses ;-)
>>
>>        hth,
>>
>>        Mike Brooks
>>        CCIE# 16027 (R&S)
>>
>>
>>        On Sat, Sep 20, 2008 at 3:10 PM, Todd Franklin <toddnh65 at gmail.com>
>> wrote:
>>        > Phone system went "kerflunk" yesterday.  Found a 7940 with a
>> Linksysy
>>        > wireless router plugged into the PC port of the phone.  Could
>> that have done
>>        > it?  I seem to remember one VAR telling me this was a grand way
>> to take an
>>        > IPT network down.
>>        >
>>        > Also, is there any configuration I can add to the 3560s that
>> would
>>        > "disallow" this configuration?
>>        >
>>        > Thank you!
>>        >
>>        > Todd
>>
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>>        >
>>        >
>>
>>
>>
>
>