E4200 wireless at home

Question

Hi,
My name is Aad Doix, from the Netherlands (excuse for my English) and to get a strong signal everywhere in our house I bought myself an E4200 (with firmware version 1.0.02). A friend of mine did do the setup which is the following:
From our provider there is a Zyxel which delivers internet and telephone signal. In this Zyxel the wireless option is disabled. The E4200 is connected to this Zyxel and handles the wireless network in bridge modus. Both are secured with a long and strong password, the wireless private connection has a strong password, the guest network (now disabled) had a weak password.
I am a noob when it comes to routers so I have multiple questions about this E4200 and in general. Hopefully this board can help me out?
1) in bridge modus there is no possibility to check on DHCP, so to me the only way to check who is connected, is to use that mac adress list. But how does this list work on the E4200? When I had my guest network available and I was connected to my private network I saw unknown users connected (I did not give them any access) on this mac adress list. Does this list show any connected user as well of the private network as for the guest network?When I disabled the guest network, most users disappeared on that list. I can not find any answer on this on the whole internet.
2) Does the mac adress filtering work correctly on that E4200? When I add adresses to the list to exclude them from connecting, these specific adresses still showed up in the list as connected.  When I put save mac adresses in the list as only authorized to get connected, all mac adresses (known to me and the unknown users from issue 1) shows up in that list. It looks to me that this function is not working properly, but hopefully it is me who does not understand this functionality?
3) The E4200 provides an 5-GHz connection (N) and a 2.4GHz connection (G). My computer is always connected to the N-connection and I see this confirmed in the mac adress list as I can see the correct mac adress. But there is most of the time (!) another different (!) mac adress connected to the G-connection. It seems that my computer is connected with both connections on different mac adresses or do I talk no sense at all now?
4) What exactly is the range of an E4200 when speaking wireless? My stepson has a blackberry and it was connected to the private network last Monday according to that mac adress list, but he was 2 miles away! Later on the BB mac adress was gone and for the last days it sometimes pops up in the list, allthough the BB does not use our network at this moment. Does this list have problems with some sort of cache?Or does this list most of the time show any known or predefined devices Oo do I have to restart the E4200 anytime when I change functionality?
I could not find any answers about above mentioned questions, not in the manual, not on the internet. Hopefully you guys / gals can help me?
Today I will try to install the latest firmware (1.0.03?) which maybe can give me more insight in above.
Kind regards and thanks in advance for replying,
Aad ~ Doix

Answer 1

1.  There is no list of wireless clients just for the guest network.  The list is only wireless or not wireless.  So you would see all your wireless clients listed.  To avoid having people use your wireless you should use WPA2-personal with a strong passphrase for the 2.4GHz. and 5GHz. wireless, and then a strong password for the guest wireless (2.4GHz. only), which you have apparently done.  So the thing to take away from this is that you may not recognize all the MAC addresses you see in the "Local Network" "DHCP Client Table" list just because *every* client that's on your network has a MAC address.  If you have a TV or a blue-ray player or a bridge or a smartphone, etc. they all have MAC addresses.  So be careful concluding that you have intruders on your wireless network.
The other thing that you also ask later is whether this list of clients mentioned above has a cache.  Yes, it will keep clients listed after they have actually stopped using your network.  That's what the "Refresh" button for the table is for.  When you click the refresh button, it should drop the Blackberry that's left the house until it is on your wireless again.  So again, if you have people with smart phones that were using your network, they will stay listed for some time, unless you click the "Refresh" button.  There is apparently some length of time after which it flushes itself, since I see wireless and wired clients disappear after some time when they stop being active on the network, but it takes a while.
On the other hand, you say that when you disabled the guest network a bunch of MAC addresses disappeared.  If you never use the "Refresh" button, this could be no longer valid guests that had been at your house, and disabling the guest network flushed them out of the table.  Hard to say.  It seems unlikely that anyone would crack the strong password that you mention, unless it has gotten passed around to other people.  You can always test this by changing the guest network password to another strong password, and see what happens from then on.
2.   I've not used the MAC address filtering, so I don't know if it works.  I generally assume that something works, and that I'm not using it quite correctly until I'm pretty sure that it doesn't work *smile*.  Again, remember that the "DHCP Clent Table" will not drop entries immediately, so if you turn on MAC address filtering, I doubt that will cause it to drop existing entries.  If you clicked on the "Refresh" button after doing that, that might help you in figuring out if the MAC address filtering is doing it's job.  Again, I've never used that in years of using routers, never had a need for it since the built-in router wireless security has always worked for me.
3. You can have mutliple MAC addresses on a single computer, which corresponds to multiple network interfaces, but this is very unusual in the consumer world, and you never see multiple wireless interfaces on computers.  A laptop or smart phone can only connect to either 5GHz. or 2.4GHz., not both at the same time.  There must be a wireless-g client at your house that you've forgotten about.  Again, it is possible that your passphrase has gotten passed around between people somehow, you can change it anytime to test this.
4. The range of 2.4GHz. wireless is much less than 2 miles, that's the DHCP client list not getting flushed again.  As to why your stepson's blackberry would pop up in your DHCP client list when he's not around, that sounds flaky.  I can see it being retained for some time, but it shouldn't just come back unless the phone does *smile*.  Can't explain that one.  As far as restarting the router when you change functionality, it should re-boot itself when you change something that requires a restart, my E4200 does that.  So you shouldn't have to do that.  Routers, like all complex electronic equipment, can get into a state where they need to be power-cycled and/or reset, but that should be very rare.
Sorry that this is so long, but you had several long questions with lots of content *smile*.