08-02-2010 08:46 AM - edited 03-06-2019 12:16 PM
I have a Catalyst 3550 with PoE (WS-C3550-24-PWR) that has 1 x AP 1220 connected using PoE. When I add 2 x AP 1242s, I get an insufficient power message. How many devices using PoE can this switch support? I'm running IOS v.12.1(19)EA1c - could this be an IOS update issue? Thank you in advance. -Jason
08-02-2010 09:00 AM
Hello,
If you issue "show power inline", it will tell you the amount of power
delivered and the amount of power remaining. Typically the switch will have
360W of power and it can deliver 15.4 W per interface (max).
Hope this helps.
Regards,
NT
08-02-2010 09:58 AM
Hi,
Thanks for responding. See below for the results of the 'show power inline'-
----snip--------------------
Interface Admin Oper Power Device Class
(Watts)
---------- ----- ---------- ------- ------------------- ----------
Fa0/1 auto on 6.2 cisco AIR-AP1220-IO n/a
Fa0/2 auto on 15.0 Ieee device
Fa0/3 auto on 15.0 Ieee device
Fa0/4 auto off 0.0 n/a n/a
Fa0/5 auto off 0.0 n/a n/a
Fa0/6 auto off 0.0 n/a n/a
Fa0/7 auto off 0.0 n/a n/a
Fa0/8 auto off 0.0 n/a n/a
Fa0/9 auto off 0.0 n/a n/a
Fa0/10 auto off 0.0 n/a n/a
Fa0/11 auto off 0.0 n/a n/a
Fa0/12 auto off 0.0 n/a n/a
Fa0/13 off off 0.0 n/a n/a
Fa0/14 off off 0.0 n/a n/a
Fa0/15 off off 0.0 n/a n/a
Fa0/16 off off 0.0 n/a n/a
Fa0/17 off off 0.0 n/a n/a
Fa0/18 off off 0.0 n/a n/a
Fa0/19 off off 0.0 n/a n/a
Interface Admin Oper Power Device Class
(Watts)
---------- ----- ---------- ------- ------------------- ----------
Fa0/20 off off 0.0 n/a n/a
Fa0/21 off off 0.0 n/a n/a
Fa0/22 off off 0.0 n/a n/a
Fa0/23 off off 0.0 n/a n/a
Fa0/24 off off 0.0 n/a n/a
----snip--------------------
Below is the power draw on the AP from Cisco's website -
------snip-------------------
12.95W maximum
Note: 12.95W is the maximum power required at the powered device. If the access point is being used in a PoE configuration, the power drawn from the power sourcing equipment will be higher by some amount dependent on the length of the interconnecting cable. This additional power may be as high as 2.45W, bringing the total system power draw (access point and cabling) to 15.4W.
-----snip-------------------
Based on this info, all should be ok. Any ideas on what else to check?
-Jason
08-02-2010 10:12 AM
Hello,
Can you please post the output of "show power inline", "show interface
Regards,
NT
08-02-2010 10:53 AM
08-02-2010 11:44 AM
Hi Jason,
As per the output it only shows that the you have 3 devices connected and drawing power from the switch which is normal and the switch should be fine.
Can you send me the show power output and also can you let me know what device you are trying to conect and what is the minimum pwer requirement for the same.
HTH
Rahul
08-02-2010 12:08 PM
Rahul,
See below for requested info. The APs are 1242s.
----snip--------------------
Interface Admin Oper Power Device Class
(Watts)
---------- ----- ---------- ------- ------------------- ----------
Fa0/1 auto on 6.2 cisco AIR-AP1220-IO n/a
Fa0/2 auto on 15.0 Ieee device
Fa0/3 auto on 15.0 Ieee device
Fa0/4 auto off 0.0 n/a n/a
Fa0/5 auto off 0.0 n/a n/a
Fa0/6 auto off 0.0 n/a n/a
Fa0/7 auto off 0.0 n/a n/a
Fa0/8 auto off 0.0 n/a n/a
Fa0/9 auto off 0.0 n/a n/a
Fa0/10 auto off 0.0 n/a n/a
Fa0/11 auto off 0.0 n/a n/a
Fa0/12 auto off 0.0 n/a n/a
Fa0/13 off off 0.0 n/a n/a
Fa0/14 off off 0.0 n/a n/a
Fa0/15 off off 0.0 n/a n/a
Fa0/16 off off 0.0 n/a n/a
Fa0/17 off off 0.0 n/a n/a
Fa0/18 off off 0.0 n/a n/a
Fa0/19 off off 0.0 n/a n/a
Interface Admin Oper Power Device Class
(Watts)
---------- ----- ---------- ------- ------------------- ----------
Fa0/20 off off 0.0 n/a n/a
Fa0/21 off off 0.0 n/a n/a
Fa0/22 off off 0.0 n/a n/a
Fa0/23 off off 0.0 n/a n/a
Fa0/24 off off 0.0 n/a n/a
----snip--------------------
Below is the power draw on the AP from Cisco's website -
------snip-------------------
Power Draw for 1242
12.95W maximum
Note: 12.95W is the maximum power required at the powered device. If the access point is being used in a PoE configuration, the power drawn from the power sourcing equipment will be higher by some amount dependent on the length of the interconnecting cable. This additional power may be as high as 2.45W, bringing the total system power draw (access point and cabling) to 15.4W.
-----snip-------------------
Please let me know if you need additional info.
Thanks,
-Jason
08-02-2010 12:13 PM
Hello,
Which port you have connected the AP to? Also, in the output you have sent,
we are missing the total power details.
3550_1#sh power inline
Available:360(w) Used:0(w) Remaining:360(w)
Interface Admin Oper Power Device Class Max
(Watts)
08-02-2010 12:16 PM
Hi Jason,
Thanks for the update!
Where as you have not provided the total power and power available in the show power inline output. Please share the same!!
How many AP's are we trying to connect to the switch at a time.
HTH
RAHUL
08-02-2010 12:23 PM
Rahul,
The command does not give me the total power.
There is currently one AP on the switch (on port 1). I added 2 x 1242s on ports 2 & 3.
I am going to upgrade the IOS tomorrow and see if that helps.
Thanks,
-Jason
08-02-2010 12:25 PM
Hi Jason,
Can you just give me the complete output of the show power inline ?
HTH
Rahul
08-02-2010 12:30 PM
See below -
-----snip-------
switch#sh power inline
Interface Admin Oper Power Device Class
(Watts)
---------- ----- ---------- ------- ------------------- ----------
Fa0/1 auto on 6.2 cisco AIR-AP1220-IO n/a
Fa0/2 auto on 15.0 Ieee device
Fa0/3 auto on 15.0 Ieee device
Fa0/4 auto off 0.0 n/a n/a
Fa0/5 auto off 0.0 n/a n/a
Fa0/6 auto off 0.0 n/a n/a
Fa0/7 auto off 0.0 n/a n/a
Fa0/8 auto off 0.0 n/a n/a
Fa0/9 auto off 0.0 n/a n/a
Fa0/10 auto off 0.0 n/a n/a
Fa0/11 auto off 0.0 n/a n/a
Fa0/12 auto off 0.0 n/a n/a
Fa0/13 off off 0.0 n/a n/a
Fa0/14 off off 0.0 n/a n/a
Fa0/15 off off 0.0 n/a n/a
Fa0/16 off off 0.0 n/a n/a
Fa0/17 off off 0.0 n/a n/a
Fa0/18 off off 0.0 n/a n/a
Fa0/19 off off 0.0 n/a n/a
Interface Admin Oper Power Device Class
(Watts)
---------- ----- ---------- ------- ------------------- ----------
Fa0/20 off off 0.0 n/a n/a
Fa0/21 off off 0.0 n/a n/a
Fa0/22 off off 0.0 n/a n/a
Fa0/23 off off 0.0 n/a n/a
Fa0/24 off off 0.0 n/a n/a
switch#
-----snip-----------
-Jason
08-02-2010 12:35 PM
Hi jason,
This is weired ! you are not getting the complete outputs with the commands. We are really not sure how much power it is consuming and how much is available.
Please proceed with a reload or upgrade and let me know the updated status on the same.
HTH
Rahul
08-02-2010 12:54 PM
Hello Jason,
The issue seems to be hardware related. In order for us to narrow down the
problem, please follow the below troubleshooting steps:
Step 1: Disconnect the AP in question
Step 2: Configure logging on the switch
configure terminal
logging on
logging buffered debugging
Step 3: Enable inline power debugs
switch# debug ilpower events
Step 4: Now connect the AP in question and wait for a minute
Step 5: Now collect the output of "show log"
The output will show us the negotiation between the AP and the switch with
regard to the power requirements. Typically, the switch will reject power
allocation if the AP is asking for power beyond what switch can provide or
if it does not recognize the AP at all. Once we figure out what is the root
cause, it is easy to find a fix.
Hope this helps.
Regards,
NT
08-02-2010 03:12 PM
I am going to upgrade the IOS tomorrow and see if that helps.
Upgrade to what? There are two directions. You can upgrade to either 12.1(22)EA13 or 12.2 series. If you have the service contract, upgrade to the 12.2 instead (IP Base).Discover and save your favorite ideas. Come back to expert answers, step-by-step guides, recent topics, and more.
New here? Get started with these tips. How to use Community New member guide