Connection issues EX6200 Wireless Extender connecting to Comcast Cable modem/router
I've got a brand new EX6200 I'm setting up for a customer to provide connectivitiy to their guesthouse. Their main home is about 50 yards from the antenna at the guest house. The EX6200 has one of the antenna ports plugged into an outside directional high gain antenna. I've got a very good signal, green indicator on the 2.4GHz network and good coverage to the guesthouse with a green device indicator. The Comcast modem does not have 5GHz so no connection on that circuit externally. With this setup my Dell laptop has no problems connecting and decent Internet speeds as tested by speedtest.net, 19Mb's down and 12Mb's up. I can't get anything else to connect to the Internet on this network though. I tried two iPhones, and iPhone 4 and an iPhone 6, and two other laptops. One a Dell and one an HP. They all connect to the EX6200 just fine and show they are connected, but no Internet traffic flows. No web pages will load. I've been pulling my hair out trying to determine the issue. I did notice that the Comcast modem is using IPv6 as well as IPv4. My laptop connection shows both IPv4 and IPv6 IP addresses when connected. You can't tell on the iPhones if there is an IPv6 address or not, and the older Dell laptop shows the IPv4 address but nothing on the IPv6. My laptop and the older Dell are both running Windows 7. The HP laptop is running Windows 10. I brought the EX6200 into my office and hooked it up to a WatchGuard XTM-25w. I enabled IPv6 on the WatchGuard to see if I could duplicate the problem. Both my laptop and my iPhone 6 are connecting to the Internet fine with this setup. Has anyone else seen this behavior or have any ideas?
FYI, I tried an amped Wireless extender on this first and with a 79% signal to the Comcast modem/router the amped unit would drop connection every couple of minutes, but it did allow me to connect with the same devices that are connectiong to the EX6200, the connection just wasn't stable. I would test the signal level over and over and it varied between 77% and 79%, never lower. I saw from reviews that many others had the same dropping connectivity issues with the amped unit so I figured they were not worth another try.
Hmm, it's a bit unusual to be redirecting only one of the antenna ports to an external antenna. You are going to lose the ability to leverage multiple spatial streams normally supported by a multi-antenna device like the EX6200. Oh well. Given that your first Dell is working, obviously one spatial stream is working, so I'll leave it at that.
Are you sure the other Dell and HP machines are getting valid IP addresses? If they begin with 169.254, then they are not valid IP addresses. If you have Access Control enabled on the EX6200, then that could explain why they cannot access the Internet. You will need to add entries to permit them through.
If your devices are getting valid IP addresses, then I would try disabling IPv6 on the Comcast modem/router. As much as IPv6 is the wave of the future, there are still problems with its deployment. Reliable Internet access is still problematic. Since IPv6 is still optional for the most part, there really is no harm with disabling it.
FYI, I'm using both external antenna ports. One has one of the included external antennas attached and the other has a high gain, directional, outdoor antenna attached with an appropriate cable so that I could get line of sight connection to the router in a separate building. That part is working fine.
The IP addresses of the other devices, Dell & HP laptops and iPhones, are in the proper class A subnet provided by the DHCP server on the Comcast modem, in the 10.0.0.* range. The Comcast router is 10.0.0.1 and the Netgear EX6200 is at 10.0.0.20. I do not have access control enabled on the EX6200 either.
I wish I could turn of the IPv6 on the Comcast router, I tried, but they have the interface so dumbed down there is no option to turn it off. They have made it so a person can have a little bit of control but nothing that would allow them to screw things up enough that they couldn't connect to the Internet. 😉 I wish the EX6200 had the ability to be a DHCP server. If it did, then I could eliminate any possible IPv6 issue that might be causing the problem. Since the EX6200 does not have this option, then I have to either hard code the IP configurations to the devices, (not an option because they need it to be available to devices that come and go too, and they have no ability themselves to hard code IP configs), then I have to rely on the DHCP server in the Comcast modem/router. 😞
Each antenna is responsible for providing a link rate up to 150 Mbps at 2.4 GHz. Working together, they provide up to 300 Mbps. While I understand the purpose of the high gain antenna is to enable the extender to connect to the router 50 yards away, you should understand that the link speed of this connection can never be greater than 150 Mbps. The link speed will probably be much less due to the distance.
I'm not saying that your setup is wrong. Obviously, you can't use two directional antennas without sacrificing the ability to service local Wi-Fi devices. I am just pointing out that the effective bandwidth of this setup is reduced.
It's too bad the Comcast router interface is dumbed down. Can you experiment with disabling IPv6 on the non-working Dell or HP and see if that affects their Internet access? It would help determine whether IPv6 is involved or simply a red herring. Are they able to ping IP4 addresses, like 8.8.8.8 (Google's DNS server)?
Thanks again. I understand the sacrifice of bandwidth with the current setup and in this case that's not an issue. The only reason for networking in this home is for Internet connectivity and even Internet speed is not a big concern for them. They have been living with Clear Wireless for their Internet in the guesthouse and the best they ever got was about 3Mb's down and about 1Mb up, so anything above that will be an improvement. Clear is going away so that's the reason for the changes. They would rather not have more expensive cellular data plan if we can utilize their current Comcast circuit.
I did disable IPv6 on the affected Dell laptop and it did not fix the problem so the IPv6 may not have anything to do with the problem. It's just the only thing odd I've found about the whole thing. As I mentioned, I setup one of my WatchGuard routers in my office with IPv6 also and I cannot duplicate the problem there. I can connect with my iPhone to the EX6200 connected to the WatchGuard just fine there. In the guesthouse setup I could ping within the private network but not out to the Internet. I'm thinking there is just something funky about the way this unit is communicationg with the Comcast modem/router.
