5 replies to this topic

[alphamale]

hello

i have forgotten how to set up a wireless router as a access point----no natting. if someone would be kind enough to give me a few pointers to get me going.


bought an Netgear WNR2000v3 N300 for cheap. i wanted to use it only for my android connections because its 2.4/N and my regular accesspoint is G. it still works great but wondering if a more recent equipment/radio would give me better pageloads.so i spent $16 and bought it.

i have a firewall router(dhcp) into a switch with wireless handled by an accesspoint(no dhcp).

live in the country and use mac filtering and have my android devices set in the filter.

now in the n300 i did not setup the internet connection, unchecked where it said use router for dhcp,turned on the wireless radio switch, set the ip, subnet,gateway as static. took a cable and pluged it one of the 4 lan ports and the other end in the switch.

did i miss anything? Thanks

[Simon-]

Turn off DHCP and then plug your existing router into one of the LAN ports and leave the WAN port unused.

This works for any router.

(Except for some F*&((*&* D-Link I had to configure which hijacked the DHCP packets and replaced the default gateway even when DHCP was switched off)

[+BudMan]

And what dlink was that - I really find that hard to believe with the way that dhcp works.

So you have say router 1 with a few lan ports, maybe even another switch hanging off 1st router, then say your dlink being used as AP plugged into either first router lan or switch.

Now your client sends out dhcp discover broadcast. Any dhcp server on the network that sees that will send out a dhcp offer, again broadcast to 255.255.255.255, lets assume this is your router. That broadcast will go out every port on its lan switch, then every port on switch and should go out then every other port on your AP dlink, and the wireless even.

So your saying that your dlink intercepted this packet, and changed the dhcp option (3 I do believe) in the packet to its IP, and then resent the packet?? What about devices that were connected to the routers lan port, or the switch. There would be no possible way for the dlink to mess with those packets.

My guess is more that you dlink did not actually turn off its dhcp server, etc.

But you are correct turning off dhcp and just using a lan port is how you use any wireless router as just an accesspoint. What I would suggest is you also change the router your going to use as ap lan IP to something that is on your first routers network, outside its dhcp scope of course so that you can then access the now AP and setup its wireless network how you want, ssid, psk, security options, etc.

[Simon-]

I don't remember which model it was, it was for a client. I suspect that when DHCP was turned 'off' in the settings it was actually still turned on, maybe in attempt to be a DHCP relay agent, because all the DNS settings etc. configured on the actual DHCP server was the same, only the gateway was changed to the D-Link's IP address.

There must have been two devices responding to DHCP at the same time - the D-Link and the main router, except that the D-Link was always quicker to give out the leases. Unplugging the D-Link fixed the problem (DHCP leases given out with the D-Link as the default gateway). I also tried factory resets.

I ended up doing a firmware update, which fixed the problem permanently. I checked the release notes after and there was no mention in the release notes about this being an issue. I suspect they just didn't document it.

Just through I would mention it in case anyone else comes across this problem with D-Link. I suspect that most IT folk would not come across this problem because we like to stay away from D-Link for all Wireless Gear because of their bad reputation (well deserved in this case for having such an absurd bug), but sometimes we find ourselves stuck with it when it is bought by someone else.

[+BudMan]

would love to see that bug actually. Were the only clients that were seeing this change of the router wireless?

How would it know to hand out the dns that was configured on the first dhcp server? And again it can not stop the packets from being seen by the other clients that are broadcasted. So it would be impossible for it to be faster while changing out the router and then rebroadcasting it.

While I don't doubt there was something odd going on, think we are missing the details of the actual problem. Changing out the gateway of some other dhcp servers packets with its own does not seem viable as what was actually going on to be honest.

But yes you need to make sure that your dhcp server on your router you want to use as AP is disabled!! Or you can have clients that don't work because they point to AP as their gateway when its not.

And if was acting as a dhcp relay, that too would be after the other packets have already been put on the wire for the AP to relay them. Yes a dhcp relay modifies the packet, has to change the mac, etc.. But relays are meant to work across segments not relay the traffic back out, even if was relaying the packet when it was not suppose to.. How would it block the other broadcast? So there is no way this relay would be there before the first broadcasts, etc.

[Simon-]

BudMan, on 01 December 2012 - 15:04, said:

would love to see that bug actually. Were the only clients that were seeing this change of the router wireless?

How would it know to hand out the dns that was configured on the first dhcp server? And again it can not stop the packets from being seen by the other clients that are broadcasted. So it would be impossible for it to be faster while changing out the router and then rebroadcasting it.

While I don't doubt there was something odd going on, think we are missing the details of the actual problem. Changing out the gateway of some other dhcp servers packets with its own does not seem viable as what was actually going on to be honest.

OK maybe it wasn't "relaying" it or "changing packets on the fly" maybe it was listening for other DHCP servers on the network, then taking the liberty to automatically become a 'secondary' DHCP server even though DHCP was turned 'off' by cloning the records given out by the other DHCP server, and then due to a bug (apart from doing this without being told) the default gateway is not cloned properly and sets itself as the default gateway even when it's not. Maybe the technical term is "doing some pretty weird stuff". Maybe it is D-Link trying to be smarter than what they actually are and then not testing their product in this configuration to see if this actual 'feature' works.

The D-Link was connected to the rest of the network via one of it's LAN port, therefore it was part of the same segment as the rest of the network.

All clients on the network set to get a DHCP address were experiencing the issue, even if not directly connected to the D-Link. Occasionally a client would get the correct address (1 out of 10 chance - rough estimate). If I unplugged the D-Link from the network, clients on the rest of the network would always get given the correct default gateway 10 times out of 10. Plug D-Link back in and same problem starts. The main DHCP server was a Netgear router, and not due to latency or anything, I think it was just a tiny bit slower giving out DHCP addresses most of the time, but still appeared to be a race condition.