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arielc
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Problems at moments of high traffic

Wed Oct 07, 2009 3:50 am

First sorry for my terrible english...
I have two nodes of similar characteristics working, one has a RB532 with three radios (one XR2 and two R52) and the other is a RB433 (non AH) also with three radios (three R52H).
The radios have each their sectorial panel of 120º.
The two boards are configured as Bridge no routing or bandwidth control in the APs.
Each of these nodes have conected of about 20 clients distributed in the three panels.
All work fine but I have the serious problem of which per moments, when there is much traffic, they go away pings by clouds, becomes impossible to enter to the CPEs in remote form and begin the corresponding complaints of the clients.
To people that I consult it says to me that a node of those typical must be able to take care of about 100 clients like minimum, but my doubt is in knowing if the Routerboard is being small in processing capacity, which I doubt since at the moments critics the resources at the most mark to 20% of CPU used and half of the memory occupied.
Firstly, I think that the problem was originated by radio interference of other near nodes that there are in the zone, I changed the channels until being annoying to the R52 but always it seems to be solved but the problem returns soon after.
Somebody say me that the R52 is unstable to work in 2,4 but the problem also are present in the clients connected to the XR2 thus also is discarded.
I have been clearing clients little by little, deriving to another equipment, to diminish traffic but the subject is that the problem returns to appear.
I have about 18 or 19 clients in each RB which seems to me a waste, fodder that those routerboards must give for but. I have read many possible solutions and I have applied them to almost all but like I say before, the problem always returns, apparently the only solution is to diminish the traffic to the maximum.
I try changing the ack timeout agreed to the distance of each client, I try too with "hardware retries option" but nothing.
The CPEs are some RB411 and some Ubiquiti Nanostation2.
What can I do to solve this problem, how many clients can receive each RB or radio ?
Thanks in advance for any sugestions or help.
 
guille4
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Re: Problems at moments of high traffic

Wed Oct 07, 2009 5:55 am

Your problem is mostly probably due to high external interference. Maybe intentional !!

Resource hardware in your case is ok. No more cpu or memory is necessary. The power of the wireless cards is ok too.

Each card can manage about 30-40 clients without problems.

You can try doing a spectrum analysis with the snooper and freq. usage options in wireless interfaces (in winbox), to see if anyone is perturbating your freqs. Maybe you have full load of traffic in 2,4 ghz in your area, not necessarily your own traffic.

Other tips:

1) you can use wireless access list, close each radio and start to give access to one by one client. In some circunstamces only ONE client with trojans or virus CAN originate loops, or denials attacks. Giving access for each client you can look if the transmission going down or follows ok.

2) Put rstp on in the bridge interface, to avoid local loops due a malfunctions cpe or other unknown causes.

3) In 2,4 ghz freq is NOT recommended clients in a distance major of 1 mile. After that, starts the problems...

4) Put the focus in yur log. Too much connect / disconnect messages?

Lastly but not least relevant: the problem -when it appears-, its manifest at the same time for all your clients or only by sector (by panel)? or by AP ? or by each client at differents moments?
 
shielder
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Re: Problems at moments of high traffic

Wed Oct 07, 2009 6:30 am

you will cause self interference between your own sectoral antenna.

you need to use 2412, 2442 and 2472 as the channel of 3 antenna to minimize self interference, but i think it would be impossible as the air does not only belong to us.
 
arielc
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Re: Problems at moments of high traffic

Wed Oct 07, 2009 4:19 pm

Thanks for your replies...
I have tried already changing the channels, searching firstly the minor ocupied frecuencies, but nothing happens.
Now I´m using channels 2412, 2442 and 2472 and sometimes I rotate the channels to try something, but nothing.
The problem is by sectors, normaly the more loaded sectors, but sometimes the sectors that have a few clients are afected too, I don´t understand this behavior.
At the critical moment the traffic of one interface, for example WLAN1 is about 800 Kbps or more, when two interfaces are traffic like this all the system is totally inestable.
Is something related with the amount of traffic, the system work amaizingly fine when the traffic is little.
I´m thinking in change the RB532 with one RB433AH but I don´t know if this is the solution.
At the moment I will activate the rstp option.
Thanks again for any comments or ideas...
 
guille4
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Re: Problems at moments of high traffic

Wed Oct 07, 2009 10:01 pm

Maybe the problem is not about how much traffic in kbps himself. And not about how much clients you have in each sector.

Maybe you suffering a bottleneck with the amount of simultaneous connections at the same time. I've experienced dozens of issues with clients thats have trojans or viruses.

They trying all the time to open connections in mass... and the wireless network goes down. You may apply some restrictions in the firewall rules like filters to the ports mostly commons objectives of viruses and worms... like ports 135-139, 445, 1433-1434... etc. In fact, by example, ARES tries all the time to open connections like a DoS attack... other virus thats I detect was pinging to all your ip lan segment... really this are tragic for your network if you not applies some politics of control in each AP.

Read this, may help you.

http://wiki.mikrotik.com/wiki/Dmitry_on_firewalling

regards.
 
arielc
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Re: Problems at moments of high traffic

Thu Oct 08, 2009 4:11 am

It is very possible...
But this is controlable ? remember, the APs are function like bridge no routing or bandwidth control is aplicated on the AP.
Now I´m thinking if I have not committed an error in the configuration respect to the bridge interface.
I create the bridge, then create a port to the eth interface and create too a port for each WLAN interface, may be this last are not necesary, only to test I remove this ports, activate rstp and (aparently) all work fine.
Pardon by my ignorance and my terrible english :-)
Thanks !
 
guille4
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Re: Problems at moments of high traffic

Sun Oct 11, 2009 10:15 pm

The ports of the bridge must be the eth port AND each wlan attached to the port.

But, if you want filter some type of traffic, then you must use the firewall filter for bridges.

Try:

interface bridge settings set use-ip-firewall=yes
or in winbox click on BRIDGE menu then on the SETTINGS menu and check "use IP firewall".

After doing this you can enabling filter in ip firewall filters.
 
popcorrin
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Re: Problems at moments of high traffic

Tue Oct 13, 2009 5:12 pm

It might be internal interference. Many people have reported difficulties when running 2 or more cards on the same band while using an RB433. I think if you search the forums you will find some threads regarding this.
 
arielc
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Re: Problems at moments of high traffic

Fri Oct 16, 2009 6:02 pm

Guille4...
Could you explain to me how set up the ports in the bridge...
Before I create one port to each interface, that is, one for eth and one for each WLAN interface, now, after try diferent thinks, I disabled all WLAN ports, and the system continues working.
Popcorring, it is very possible what you comment (sorry for my english) all my other nodes are working fine, but these, have only one interface, or someones are one interface in 2,4 and other in 5,8 ghz...
I will search for information in the forum, but I believe that the best solution is going to be to separate, one routerboard for each panel :-(
Greetings

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