Airport looses connection with Comcast router

Question

Level 1

67 points

Airport looses connection with Comcast router

I just switched from DSL to Comcast cable, business class, and now I have to reboot the Comcast router every few hours. My Airport router (the time capsule version) appears to loose it’s connection. I discovered that if I bypass it with an ethernet cable from the Comcast router the internet works fine. When I loosed the internet connection, Airport Utility shows the Airport as green but the icon for the internet is yellow. I tried renewing the DHCP lease on my MacBook Pro but that didn’t help. Do I need to switch from DHCP to a static address on the Airport router? Or something else?

MacBook Pro with Retina display, OS X Yosemite (10.10)

Posted on Mar 29, 2015 7:36 AM

Reply

Answer 1

Best reply

LaPastenague

Level 9

67,208 points

Mar 29, 2015 1:59 PM in response to Dan Bryant1

What comcast modem or gateway do you have??

What model is your TC? A1xxx from the base please.

The setup of the TC will depend on the main modem from comcast.. for a pure modem the TC should be router mode.. for a gateway the TC should be bridged.

However the latest TC (tall AC model) has shown problems with certain modems and routers in wan connection.. it drops out as you have experienced.. this is a very common problem.

Fill us in on the setup particulars and we can suggest some approaches to solution.

Reply

Answer 2

Dan Bryant1 Author

Level 1

67 points

Mar 30, 2015 11:57 AM in response to LaPastenague

The modem is Netgear CG3000DCR, an "Advanced modem gateway". I cannot find a model number on the base (print is too small) but it is the tall model, 802.11AC, purchased last year. I changed it to bridge mode and that seems to have helped. However one of our computer's, an older Mac Mini Intel Core Duo 2, is having trouble staying connected. The wifi keeps dropping out even though it is only 10 feet from the TC. We also have it connected to ethernet but that connection doesn't seem to work always either. When I ran speedtest.net I got 19 mbs download compared to 55 mbs on my MacBook Pro connected via wifi.

Reply

Answer 3

Mar 30, 2015 1:49 PM in response to Dan Bryant1

Ok.. the CG3000 is a model often used by our cable providers here.. although I seldom hear of it being used by Comcast or other US suppliers.

Try plugging the ethernet cord from CG3000 to a LAN port instead of WAN.. in bridge the TC doesn't care which port you use. That might help some.

The mini that is having issues.. what OS is it running??

If you run it with ethernet turn off wireless. Make sure ipv6 is set to link-local only in the ethernet setup on the computer.

No luck then it might take some more work because with your MBP working ok the issue seems to not be the TC but the mini.

Reply

Answer 4

Dan Bryant1 Author

Level 1

67 points

Mar 31, 2015 10:45 AM in response to Dan Bryant1

The mini is running 10.6.8, I think that is far as that model will go. The only option for ipv6 is automatic or manual. At least I don't see any link-local option, unless that is somewhere else. A geek in my office said to just turn ipv6 off so I tried that and so far it seems to be working. We'll see if it gets interrupted again.

Reply

Answer 5

Mar 31, 2015 3:05 PM in response to Dan Bryant1

Geek in your office is right.. in Snow you simply turn off ipv6.

Reply