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Occasional Contributor II

Cisco reporting/reserving high POE port usage after enabling LLDP?

So, after enabling LLDP on both my Cisco 2960X switches and my Aruba 7210 controllers, the Cisco switches are reserving high port wattage for my AP's.

 

This goes for both AP-225's and AP-315's.  With LLDP off they show 15.4W both on the reserved power for the port (show power inline) and for actual AdminConsumption (show power inline interface...).

 

With LLDP on, the AdminConsumption shows the same 15.4W but with a show power inline command the Power column shows 23.8-24.5W of usage.  I guess this is how much Cisco is reserving for the port.  The problem is, that gets taken out of the total POE allotment for the switch and I then don't have enough power for additional ports.

 

Furthermore, on the Aruba controller with LLDP enabled both AP-225's and AP-315's report an LLDP Power of = Successfully negotiated at 20.2w.  Isn't that high for 315's?  Even for 225's that seems high for a single port.

 

I need LLDP on to successfully negotiate port-channels for my 225's but turning it on takes up too much of the power allotment on the switches.  Is there any way to fix this?

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Re: Cisco reporting/reserving high POE port usage after enabling LLDP?

Guru Elite

Re: Cisco reporting/reserving high POE port usage after enabling LLDP?

LLDP will reserve the maximum from the datasheet, but will typically consume less.  An AP cannot reserve more than 15.4 without LLDP negotiation.

 

Are you doing port channels for redundancy or bandwidth?


*Answers and views expressed by me on this forum are my own and not necessarily the position of Aruba Networks or Hewlett Packard Enterprise.*
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Occasional Contributor II

Re: Cisco reporting/reserving high POE port usage after enabling LLDP?

@cjoseph 


@cjoseph wrote:

LLDP will reserve the maximum from the datasheet, but will typically consume less.  An AP cannot reserve more than 15.4 without LLDP negotiation.

 

Are you doing port channels for redundancy or bandwidth?


So it's normal to see AP-225's reserving up to 25w on the Cisco side?  I even see AP-115's are reserving up to 20w.

 

I'm doing port channels mainly for redundancy but having the added benefit of added bandwidth in certain instance is not a bad thing.

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Guru Elite

Re: Cisco reporting/reserving high POE port usage after enabling LLDP?

What version of ArubaOS are you running?

 

I was asking about the dual ports, because besides the AP-335 and above, all dual port Aps reboot when the power is cut from a single port, so they are not appropriate for hitless power failover.  In addition, to get more throughput from dual-connected access points, you would need to configure a striping-ip on the controller to push more than a gig through the access point.  In most configurations, due to contention, it is not possible unless you are using 80mhz channels, to sustain more than a gigabit of throughput.  With those facts, I thought you could save some power by connecting only a single port on each AP.


*Answers and views expressed by me on this forum are my own and not necessarily the position of Aruba Networks or Hewlett Packard Enterprise.*
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Occasional Contributor II

Re: Cisco reporting/reserving high POE port usage after enabling LLDP?


@cjoseph wrote:

What version of ArubaOS are you running?

 

I was asking about the dual ports, because besides the AP-335 and above, all dual port Aps reboot when the power is cut from a single port, so they are not appropriate for hitless power failover.  In addition, to get more throughput from dual-connected access points, you would need to configure a striping-ip on the controller to push more than a gig through the access point.  In most configurations, due to contention, it is not possible unless you are using 80mhz channels, to sustain more than a gigabit of throughput.  With those facts, I thought you could save some power by connecting only a single port on each AP.


I'm running ArubaOS 6.5.4.13 on all my controllers.  The second port is not providing power the the AP's so where would the power savings come from?  I also looking into IPM but not sure how recommended that is for things like disabling USB which we don't use.

 

On a related note (though I can start a new thread on this one), all my AP-225's that have dual ports connected, if the switch powers off or reboots, those AP's will not come up at all until I physically reseat the patch cables at the switch.  This happens for all my AP-225's across 6 different sites so it can't be bad cables/patches.  Could be a Cisco thing but I don't understand what could cause that.  AP-115's come up just fine, it's just the AP-225's that won't come up on their own without a physical cable reseat.  Very odd.

Guru Elite

Re: Cisco reporting/reserving high POE port usage after enabling LLDP?

I thought you were saying the second port was also drawing power.  IPM is for mainly if you are forced to run 802.3af power, what functions you are willing to sacrifice in what order.  With LLDP  negotiation you should not have that issue.

 

With regards to the 225s that will not come up, for testing, I would dual-connect an AP225 to a switch on your testing bench and connect a laptop to the console of the AP225 and record the activity when you try to bring it up.  Hopefully you don't have a port profile on the enet1 port in that AP-group that is preventing your AP from coming up.


*Answers and views expressed by me on this forum are my own and not necessarily the position of Aruba Networks or Hewlett Packard Enterprise.*
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Occasional Contributor II

Re: Cisco reporting/reserving high POE port usage after enabling LLDP?


@cjoseph wrote:

I thought you were saying the second port was also drawing power.  IPM is for mainly if you are forced to run 802.3af power, what functions you are willing to sacrifice in what order.  With LLDP  negotiation you should not have that issue.

 

With regards to the 225s that will not come up, for testing, I would dual-connect an AP225 to a switch on your testing bench and connect a laptop to the console of the AP225 and record the activity when you try to bring it up.  Hopefully you don't have a port profile on the enet1 port in that AP-group that is preventing your AP from coming up.


No, they are not both drawing power.  Just that Cisco is reserving a high wattage for both the port that is drawing power, much more than it's actually using.  But I guess that's how Cisco does it, it must determine a high power usage on AP bootup and Cisco never lowers it after the negoatiation.

 

As for the AP's not coming up on switch power up, I found this post.  Does this make sense to you?

 

https://community.arubanetworks.com/t5/Wireless-Access/325-APs-stay-in-notconnected-state-after-Switch-reload/m-p/306096/highlight/true#M73497

Guru Elite

Re: Cisco reporting/reserving high POE port usage after enabling LLDP?

It does not specify which switches, so I cannot say for sure.  The only lesson in that post is to only single-connect your APs....


*Answers and views expressed by me on this forum are my own and not necessarily the position of Aruba Networks or Hewlett Packard Enterprise.*
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