Wireless Access

Hello,

 

We have wireless users in a test SSID which intermittently lose connectivity with a specific wired server in the same VLAN. While a wireless user lose connectivity to a single wired server, it keeps on communicating with other wired servers in the same VLAN. Hence it doesn't seem like wireless congestion or interference. 

We are runing an older version of Aruba OS 2.3. From the captures take till now it is confirmed that reply from the server gets to the controller but is never forwarded to wireless client. After sometime the communication recovers automatically.

 

It seems that there is some setting in Aruba OS 2.3 which:

 

1. decides the maximum number of connections from an IP. And if that number reaches limit it blocks all communication from that IP. Once number of connections comes down the communication again starts.

2. There is some firewall/IDS policy which is rejecting the traffic from an IP after seeing something suspicious from the IP. And the allows it after some pre-defined interval.

 

From the command I am not able to find any suitable debug or anything alarming in the logs which can provide more information on what is causing Aruba to intermittently drop the conversation.

 

Any assistance is highly appreciated.

 

Thank you.

What kind of application is this?

Are you using encryption on that WLAN?

What kind of access point?

What kind of client?

How many users are on that WLAN in total at peak?

Are wired and wireless users in the same layer2 VLAN?

 

ArubaOS 2 did not have broadcast suppression, so that might come into play...

 

Thank you for assitance.

 

What kind of application is this?

Its irrespective of application. ICMP shows the same behaviour.

 

Are you using encryption on that WLAN?

Just simple WEP.

 

What kind of access point?

AP 70. APs should not be a problem as else all worl good from the same client durint he drops to the server.

 

What kind of client?

A simple Windows 7 Laptop.

 

How many users are on that WLAN in total at peak?

MAximum 7, spread acroos 5 Aps.

 

Are wired and wireless users in the same layer2 VLAN?

Yes.

Okay.

 

Your main issue could be that you have wired and wireless devices in the same VLAN.  Wired devices can introduce data/broadcasts at whatever rate they want to due to nature of wired switching.  Wireless devices, on the other hand, are designed to back off their transmissions in the presence of traffic from wired devices.  Having wired and wireless devices in the same VLAN will cause contention issues like you are seeing, and wireless clients will always lose.  If you can separate the VLAN that wired and wireless users are on, you will certainly improve things.

 

Ok. Please note that this setup has worked good for years. And its he wired client which seems to be getting blocked by the controller. I am sure controller is blocking the wired client and would like to know any commands/debugs which can provide more information on what has been causing the controller to restrict the server for few seconds. Thank you.

When you say "The wired client is being blocked by the controller", is the controller doing the routing for wired clients?  Is the controller the default gateway for wired devices?  If not, how is the controller blocking wired clients?

 

Even though having wired and wireless clients has worked for years, increasing use of WLAN, as well as increased use of applications like multicast video could change that dramatically.

 

Its not routed, all is layer 2 switched. As I initially mentioned, it is either the number of connections or some specific traffic not liked by IDS which is blocking the communication from specific IP.

I am looking for some commands in 2.4 Aruba OS which can assist in further diagnosing what is causing controoling to drop the packets.

 

Thank you.

Unless the wired traffic is entering the controller on an untrusted interface, or there is an ACL in the ingress/egress port, there should be no policy enforced on wired traffic.  There is also no IDS enforcement for wired traffic.

 

If there is no policy enforced, there is no command that will specifically indicate what traffic is being dropped.

 

Since there is no further development being done on ArubaOS 2.x, it will help greatly if you open a support case where they can dive into the details of your deployment.  You could be running into a bug.