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New Contributor
dexter
Posts: 1
Registered: ‎02-16-2012

ping drops

Steps to approach ping drops issues

Contributor I
faisalkhan88
Posts: 48
Registered: ‎01-19-2012

Re: ping drops

Where u got PING drop issue please write something about that

Moderator
cjoseph
Posts: 11,010
Registered: ‎03-29-2007

Re: ping drops


dexter wrote:

Steps to approach ping drops issues


Ping drops happen from time to time, because of contention and other reasons.  You can reduce contention by:

 

- Enabling Drop broadcast and multicast in the Virtual AP on the Aruba Controller

- Enabling Band Steering in the Virtual AP to move clients from the 2.4ghz band to the 5ghz band on the Aruba Controller

- Making sure that wired and wireless clients are not on the same layer2 vlan

- Upgrade client wireless drivers

- Turn off power save in the Advanced Properties of clients

 

Aruba Employee
jhoward
Posts: 207
Registered: ‎11-07-2008

Re: ping drops

In my experience, if you see ping drops ALONG with long response times, then it's power-save on the client that needs to be disabled. If you see good response times across the board with ping drops, you need to look at wired issues (like client and target in same L2, multicast/broadcast issues, etc).

 

I bet power save though, just because every time ping results are a part of a wlan test metric, I find a client that has crazy power save agressiveness as part of the test.

Jerrod Howard
Federal Systems Engineer
MVP
NightShade1
Posts: 2,118
Registered: ‎10-25-2011

Re: ping drops

[ Edited ]

Hello

Cjosph for what you say its like let say

i got a vlan for IT just to give you an example

VLAN IT its vlan 10

 

And i got the VLAN IT for wired users and wireless users

 

For what i read you recomend i should create a new vlan for Wireless for VLAN IT

and having

A wired vlan for IT

and and a wireless  vlan for IT also

In this specific case im talking a vlan with no more than 30 or 50 users...  i mean wired and wireless connected at the same time.

 

If so, is there an explanaition of why having clients in the same vlan for wireless and wired users why does it provocate ping drops?

 

And JHoward i have seem that happeining just in the same way you said it.... ill check power saving mode next time i see it.

 

----------------------------------------------------
Product Manager - Aruba Networks
Alternetworks Corp
Moderator
cjoseph
Posts: 11,010
Registered: ‎03-29-2007

Re: ping drops


NightShade1 wrote:

Hello

Cjosph for what you say its like let say

i got a vlan for IT just to give you an example

VLAN IT its vlan 10

 

And i got the VLAN IT for wired users and wireless users

 

For what i read you recomend i should create a new vlan for Wireless for VLAN IT

and having

A wired vlan for IT

and and a wireless  vlan for IT also

In this specific case im talking a vlan with no more than 30 or 50 users...  i mean wired and wireless connected at the same time.

 

If so, is there an explanaition of why having clients in the same vlan for wireless and wired users why does it provocate ping drops?

 

And JHoward i have seem that happeining just in the same way you said it.... ill check power saving mode next time i see it.

 


Wired clients send traffic at line rate.  Wireless clients back off in the presence of any traffic, whether unicast or broadcast.  Put wired and wireless together and the wireless clients will continuously back off, punishing their throughput.  If you need to deploy wired and wireless in the same VLAN, use drop broadcast and multicast.

 

MVP
NightShade1
Posts: 2,118
Registered: ‎10-25-2011

Re: ping drops

Thanks for telling

ill just plan my deploy as you recomended ill have a vlan for the wired and a vlan for the wireless... i was just wondering why i mean the explanation and you just gave it

Thank you very much Collin

 

 

----------------------------------------------------
Product Manager - Aruba Networks
Alternetworks Corp
New Contributor
Brons2
Posts: 2
Registered: ‎03-31-2012

Re: ping drops

[ Edited ]

I am having problems with ping drops and high latency also.  I do have the wired and wireless on the same layer2 network, I needed to get it working in a very short period of time and my routing didn't seem to work when I put the WLANS on different VLANS.  This was for a public event that was attended by several hundreds of people.  Now that it's over I want to optimize things. 

 

I turned on bcmc-optimization on the VLAN that is shared by both wired and wireless clients.  I will also look into dropping broadcast and multicast as you mention for the AP group we are using.

 

[edit]  I turned on the option to drop broadcast and multicast on the virtual AP profile that has the same name as my heavily used WLAN.  It told me to turn on the option to convert broadcast ARP to unicast ARP, or else ARP packets would be dropped.  Don't want my ARP packets to be blocked.  So I turned on that convert broadcast arp to unicast arp on.  Should I have left it off?

 

Latency does seem a little lower, but I am still getting an occasional dropped packet.  And the latency is not as low as I would think it would be.  I'm sitting right under one of the APs and many of the pings to the controller have latency in the double digit range.  The AP is direct wired to the controller and the controller is only 20 feet away.  I would have thought the pings would be sub 1ms across the board.

 

 

Moderator
cjoseph
Posts: 11,010
Registered: ‎03-29-2007

Re: ping drops

bcmc optimization on the VLAN can be done instead of dropping broadcasts, BUT it will affect APs that discover the controller via layer2.

 

Warning: If your APs discover your controller via broadcasts (if your APs are on the same subnet as your controller), instead of DNS, you should uncheck bcmc for that VLAN and instead configure Drop Broadcasts at the Virtual AP level.  The problem with APs not discovering the controller only occurs when APs attempt to reboot, so enabling bcmc will not affect APs that are in production until they try to reboot.

 

New Contributor
Brons2
Posts: 2
Registered: ‎03-31-2012

Re: ping drops

The APs are not on the same subnet as the controller.  That much I wasn't going to change even though I was having problems getting my WLAN going on a separate layer2 network from the physical wired network.

 

I will work on getting the wireless clients away from the wired network very soon. I don't really understand why it didn't work this time but I suspect a routing problem.  I think I needed to put a static route in my edge router pointing back to the (dell) Aruba controller for subnets that are on the Aruba.  Problem is, I don't know the password to the edge router and I didn't want to do a factory reset on it with the event being imminent.