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New Member

SG300-28P - POE not correctly supported on all ports - possible firmware or hardware issue

So, I spent some time this weekend troubleshooting the issues I've had  with the new SG300-28P switch and POE to many of my devices in the  office.  As a recap, I cannot utilize all of the 24 POE ports on the switch  for POE purposes.  Really only every other port [with a few odd  combinations thrown in between]. In addition, the SG300-28P switch, on occasion, is sending POE to non-POE devices [e.g. my Ruckus Zone Director 1106].

Here are my POE devices [all 802.3 af-compliant]:

  • 3 Ruckus 7982 access points
  • 1 Pakedge access point
  • 2 home-automation controllers
  • 2 Polycom voip phones

I called Cisco support several times in regards to this problem, and they figured it was a hardware issue - a faulty switch.  So, Cisco sent me a replacement SG300-28P, which I  hooked up today.  The exact problem still occurs.  Default configuration  [fresh out of the box].  No way I can land, for example, the 3 Ruckus  7982 AP's on ports 1, 2, and 3 [or ports 1,13, and 2].  I have to put  them on ports 1, 3, and 5 in order for them to power up.  In addition, I  can't plug any other POE devices on the ports either between or below  them.   I had to skip another port bay.  This is very odd behavior!!   Two Cisco SG300-28P's in a row with the same problem.

However, I also had one of the new Cisco SG300-10P switches in my  possession for a recent project of ours.  I decided to hook up the same  POE devices to this switch.  ALL POE devices were recognized and  worked!  No need to skip a port.  And it didn't matter what device was  plugged in first or not.  I am now convinced that it is either a  hardware issue [bad power supply/transformer?] inside all of the  SG300-28P switches, or a firmware issue. 

Both of the SG300-28P switches were running firmware 1.1.2 [the  latest on Cisco's website].  So, I decided to install an older firmware  version on the SG300-28P switch that I'm returning [installed 1.1.1.8].   Here's what I found out.  I could then plug 2 POE devices [e.g. two  Ruckus AP's] in adjacent horizontal ports, but not three in a row.  In  addition, not all adjacent ports.  It's funky. For example, I could plug  an access point in ports 20 and 21, but not in 21 and 22.  No rhyme or  reason in how it worked.  And I still couldn't plug an access point in  adjacent vertical ports [e.g. ports 1 and 13].  BUT...

It's interesting that the same exact switch that would not initially  allow 2 horizontally-adjacent POE ports to be utilized WOULD allow 2  horizontally-adjacent POE ports to be utilized when running a different  firmware version.   It's also interesting to note that when plugged into  a "non-working" POE  port, the SG300-28P would actually make a small whining noise.  Very  subtle noise; I could hear it when approx. 1ft away from the switch.   The noise was not noticeable when ports were skipped [and POE actually  worked].  Therefore, I believe that Cisco has some SG300-28P firmware  bugs [at least in the last two versions of firmware] that is not truly  allowing all 24 ports to utilize POE correctly.  This problem does not  exist with the SG300-10P switch.

I'm really interested to hear what Cisco's reply and findings on this  matter would be.  And would welcome a reply from one of their senior  support team members/managers who could actually experiment with this,  too.   In addition, I'd like to know when they think a solution could be  created if it's firmware-related.  If hardware-related, I don't think  I'll be recommending any 28P switches in our projects.  Perhaps just the  regular SG300-28 with a separate SG300-10P.  It's a shame because the  SG300-28P is more of a bargain when compared to the two separate  components.

  • Small Business Switches
88 REPLIES
Green

Re: SG300-28P - POE not correctly supported on all ports - possi

Hi John,

Thanks for the interesting post. Can you post a few output commands?

show power inline

show interfaces advertise gigabitethernet xx (for what ports are of interest)

show power inline gigabitethernet xx (for each device plugged in)

show spanning-tree active

A few also things to try and test about to see if there is a way to narrow the process;

  • Set the port manual speed 1000 full duplex, 100 full duplex
  • If the products support CDP, try to disable it, see if it's a CDP min/max issue
  • Set the power inline priority (critical) for the active POE ports
  • Remove the POE from the ports which do not require it
  • Disable the EEE globally and per port
  • Verify there is not any port flapping, such as bpdu being received on the ports, etc

After fiddeling with those few settings, see if you can power your products in adjacent ports, etc. Make notes of what works, what doesn't work (if anything at all!)

-Tom

-Tom Please mark answered for helpful posts http://blogs.cisco.com/smallbusiness/
New Member

Re: SG300-28P - POE not correctly supported on all ports - possi

Thomas:

Forgive me. My networking skills are not the greatest.  [If it weren't for the GUI of the SG300's, I probably would be completely lost.]  How do i find these output commands you'd like me to post?

I did try several of the other recommendations you posted in the past.  Tried them again, but didn't seem to change anything.  I attempted turning off POE off all unused ports.  Problem remained - no adjacent port placements of the POE devices.  I also turned off CDP on a port-basis inside the SG300-28P.  And I set the power inline priority to critical for all POE devices.  No such luck.  Next, I disabled the EEE globally and per port.  No change in actions.

I'm not sure how to check for port flapping [don't know what that is]; however, I can confirm that BPDU guard is disabled/off.

What's really strange is that the default settings of the SG300-10P work just fine, while the default settings of the SG300-28P do not.

Any help with the output commands would be much appreciated.

Green

Re: SG300-28P - POE not correctly supported on all ports - possi

Hi John, enable telnet under security -> TCP / udp services then telnet the switch. Then you may run those commands.

-Tom

-Tom Please mark answered for helpful posts http://blogs.cisco.com/smallbusiness/
New Member

SG300-28P - POE not correctly supported on all ports - possible

I have a simular issue with a 802.3af compliant POE Adaptor ( http://www.ubnt.com/8023af )

Invalid Signature Counter rises in the properties section but I never get a POE device to power on at all.

I have updated to the latest software, 1.3 but still no luck.

New Member

SG300-28P - POE not correctly supported on all ports - possible

It's definitely not just a straight firmware problem; I've run every version of firmware since 1.0.0.27 on my 28P's and my phones and access points have always worked, power on all 24 ports.  The output of those commands Thomas asked for should reveal the usage and class of those PoE devices, among other useful details. I'm curious about this one.

New Member

Re: SG300-28P - POE not correctly supported on all ports - possi

show power inline

Port based power-limit mode

Unit  Power  Nominal Power   Consumed Power   Usage Threshold   Traps  

---- ------- ------------- ------------------ --------------- ---------

1     On      180 Watts     13 Watts (7%)          95         Disable 

  Port      Powered Device         State          Status    Priority   Class  

-------- -------------------- ---------------- ------------ -------- ---------

  gi1                               Auto            On      critical  class0  

  gi2                              Never           Off        low     class0  

  gi3                               Auto        Searching   critical  class0  

  gi4                              Never           Off        low     class0  

  gi5                               Auto            On      critical  class0  

  gi6                              Never           Off        low     class0  

  gi7                               Auto            On      critical  class2  

  gi8                               Auto        Searching     low     class0  

  gi9                               Auto        Searching     low     class0  

  gi10                              Auto        Searching     low     class0  

  gi11                              Auto        Searching     low     class0  

  gi12                             Never           Off        low     class0  

  gi13                             Never           Off        low     class0  

  gi14                             Never           Off        low     class0  

  gi15                             Never           Off        low     class0  

  gi16                             Never           Off        low     class0  

  gi17                             Never           Off        low     class0  

  gi18                             Never           Off        low     class0  

  gi19                             Never           Off        low     class0  

  gi20                              Auto        Searching     low     class0  

  gi21                             Never           Off        low     class0  

  gi22                              Auto        Searching     low     class0  

[0mMore: ,  Quit: q or CTRL+Z, One line:                                                          gi23                              Auto        Searching     low     class0  

  gi24                              Auto        Searching     low     class0  

show power inline gigabitethernet xx (for each device plugged in)

  Port      Powered Device         State          Status    Priority   Class  

-------- -------------------- ---------------- ------------ -------- ---------

  gi1                               Auto            On      critical  class0  

Power limit (for port power-limit mode): 15.400W

Port Status:               Port is on - valid resistor detected

Overload Counter:          0

Short Counter:             0

Denied Counter:            0

Absent Counter:            3

Invalid Signature Counter: 17583

  Port      Powered Device         State          Status    Priority   Class  

-------- -------------------- ---------------- ------------ -------- ---------

  gi2                              Never           Off        low     class0  

Power limit (for port power-limit mode): 15.400W

Port Status:               Port is off - user setting

Overload Counter:          0

Short Counter:             0

Denied Counter:            0

Absent Counter:            0

Invalid Signature Counter: 0

  Port      Powered Device         State          Status    Priority   Class  

-------- -------------------- ---------------- ------------ -------- ---------

  gi3                               Auto        Searching   critical  class0  

Power limit (for port power-limit mode): 15.400W

Port Status:               Port is off - detection is in process

Overload Counter:          0

Short Counter:             0

Denied Counter:            0

Absent Counter:            2

Invalid Signature Counter: 1

Port      Powered Device         State          Status    Priority   Class  

-------- -------------------- ---------------- ------------ -------- ---------

  gi4                              Never           Off        low     class0  

Power limit (for port power-limit mode): 15.400W

Port Status:               Port is off - user setting

Overload Counter:          0

Short Counter:             0

Denied Counter:            0

Absent Counter:            0

Invalid Signature Counter: 0

Port      Powered Device         State          Status    Priority   Class  

-------- -------------------- ---------------- ------------ -------- ---------

  gi5                               Auto            On      critical  class0  

Power limit (for port power-limit mode): 15.400W

Port Status:               Port is on - valid resistor detected

Overload Counter:          0

Short Counter:             0

Denied Counter:            0

Absent Counter:            0

Invalid Signature Counter: 0

  Port      Powered Device         State          Status    Priority   Class  

-------- -------------------- ---------------- ------------ -------- ---------

  gi7                               Auto            On      critical  class2  

Power limit (for port power-limit mode): 15.400W

Port Status:               Port is on - valid resistor detected

Overload Counter:          0

Short Counter:             0

Denied Counter:            0

Absent Counter:            0

Invalid Signature Counter: 0

  Port      Powered Device         State          Status    Priority   Class  

-------- -------------------- ---------------- ------------ -------- ---------

  gi13                             Never           Off        low     class0  

Power limit (for port power-limit mode): 15.400W

Port Status:               Port is off - user setting

Overload Counter:          0

Short Counter:             0

Denied Counter:            0

Absent Counter:            1

Invalid Signature Counter: 0

  Port      Powered Device         State          Status    Priority   Class  

-------- -------------------- ---------------- ------------ -------- ---------

  gi14                             Never           Off        low     class0  

Power limit (for port power-limit mode): 15.400W

Port Status:               Port is off - user setting

Overload Counter:          0

Short Counter:             0

Denied Counter:            0

Absent Counter:            0

Invalid Signature Counter: 0

show interfaces advertise gigabitethernet xx (for what ports are of interest)

Port: gi9      

Type: 1G-Copper

Link state: Down

Auto negotiation: Enabled

                                  1000f  1000h  100f  100h  10f  10h

                                  -----  -----  ----  ----  ---  ---

Admin Local link Advertisement    yes    no     yes   yes   yes  yes 

Oper Local link Advertisement     -      -      -     -     -    - 

Oper Remote link Advertisement    -      -      -     -     -    - 

Priority Resolution               -      -      -     -     -    - 

Port: gi10     

Type: 1G-Copper

Link state: Down

Auto negotiation: Enabled

                                  1000f  1000h  100f  100h  10f  10h

                                  -----  -----  ----  ----  ---  ---

Admin Local link Advertisement    yes    no     yes   yes   yes  yes 

Oper Local link Advertisement     -      -      -     -     -    - 

Oper Remote link Advertisement    -      -      -     -     -    - 

Priority Resolution               -      -      -     -     -    -

Port: gi11     

Type: 1G-Copper

Link state: Down

Auto negotiation: Enabled

                                  1000f  1000h  100f  100h  10f  10h

                                  -----  -----  ----  ----  ---  ---

Admin Local link Advertisement    yes    no     yes   yes   yes  yes 

Oper Local link Advertisement     -      -      -     -     -    - 

Oper Remote link Advertisement    -      -      -     -     -    - 

Priority Resolution               -      -      -     -     -    -

Port: gi21     

Type: 1G-Copper

Link state: Down

Auto negotiation: Enabled

                                  1000f  1000h  100f  100h  10f  10h

                                  -----  -----  ----  ----  ---  ---

Admin Local link Advertisement    yes    no     yes   yes   yes  yes 

Oper Local link Advertisement     -      -      -     -     -    - 

Oper Remote link Advertisement    -      -      -     -     -    - 

Priority Resolution               -      -      -     -     -    -

Port: gi22     

Type: 1G-Copper

Link state: Down

Auto negotiation: Enabled

                                  1000f  1000h  100f  100h  10f  10h

                                  -----  -----  ----  ----  ---  ---

Admin Local link Advertisement    yes    no     yes   yes   yes  yes 

Oper Local link Advertisement     -      -      -     -     -    - 

Oper Remote link Advertisement    -      -      -     -     -    - 

Priority Resolution               -      -      -     -     -    - 

Port: gi23     

Type: 1G-Copper

Link state: Down

Auto negotiation: Enabled

                                  1000f  1000h  100f  100h  10f  10h

                                  -----  -----  ----  ----  ---  ---

Admin Local link Advertisement    yes    no     yes   yes   yes  yes 

Oper Local link Advertisement     -      -      -     -     -    - 

Oper Remote link Advertisement    -      -      -     -     -    - 

Priority Resolution               -      -      -     -     -    - 

New Member

Re: SG300-28P - POE not correctly supported on all ports - possi

I have 6 VLANS configured on our office network.  Ideally, I'd like to arrange them in easy clusters [e.g VLAN1 on ports 1,2,3, 13, 14, and 15, etc.]  However, I could not get my Ruckus Wireless access points to all come up when doing such.  Only by staggering the inputs.  Therefore, you'll notice the staggered layout [e.g port 1, 3, and 5] for any device requiring POE.

Ports 9 [vlan4], 10 [vlan1], 11 [vlan1], 22 [vlan1], and 23 [vlan1] are all currently set up to support POE.  However, I could not get 3 access points to power up when plugged into any combination of 3 of those ports.  Only 2 max.

Port 1 currently has an active access point plugged into it.  The other 2 are currently disconnected [although sitting on our lab table as we continue to test these things out].  Again, what's interesting is that if we take the very same POE devices and plug them into the SG300-10P that was temporarily loaded into our equipment rack, we don't have to worry about skipping any ports.  All 3 access points can power up just fine [e.g ports 1,2,and 3].  In fact, our entire inventory of POE devices can be plugged into the SG300-10P simultaneously without any problems.  Same test gear, different switch.  And all those tests were run with the switches in default factory mode and after loading it with a config file.  We got the same behavior in either case.

And having both SG300-28P's loaded in our equipment rack, as well, made it real easy to test them with different firmware versions.  Both were factory-defaulted.  One with 1.1.2.   The other with 1.1.1.8.  We could easily move the patch cables around as needed.  And definitely got a different behavior of how the two handled some of our POE devices. 

I found another thread listed here in the Cisco support community: here.  Could they be related?  However, the Ruckus Wireless 7982 access points are definitely not pre-standard POE devices, as suggested in this other thread.  I couldn't quite tell from this thread if there could be an issue, in general, with how power is supplied to 4-port clusters within the 28-port switch.  Maybe, I misread the thread. Anyhows, looking forward to your thoughts.

Green

Re: SG300-28P - POE not correctly supported on all ports - possi

Hi John, email or pm me your tele number. I'd like to give you a call around 4pm EST today.

-Tom

-Tom Please mark answered for helpful posts http://blogs.cisco.com/smallbusiness/
New Member

SG300-28P - POE not correctly supported on all ports - possible

Hi, was this problem ever resolved? I have the exact same issue with a new SG300-28P using firmware version 1.2.7.76.

Thanks.

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