Airport Time Capsule Double NAT Error

willydimes

macrumors regular
Original poster
Jun 8, 2014
131
7
I just moved back home for the last two years of dental school. Where my room is in my parent's house the wifi is crappy and I have my time capsule that I wanted to set up my wifi with that I used back when I had an apartment at school. There isn't an ethernet port near me and for the time being my dad has me using one of those ethernet over power setups.

I plugged in my TC to the ethernet and while I can connect to the internet I am getting the flashing yellow for a Double NAT error.

I cant use the TC to extend a network that barely if at all reaches my room so that isnt an option. Any idea what I should do if anything to fix it? Thanks
 

Altemose

macrumors G3
Mar 26, 2013
9,089
444
Elkton, Maryland
@willydimes I would do a factory reset on the Time Capsule first. Do you want it to be a roaming network with one network name between the main router and the Time Capsule or do you want your own private network name?
 

willydimes

macrumors regular
Original poster
Jun 8, 2014
131
7
I was just planning on the TC being its on private name. I switched it over to bridge mode and now no error but it seems to be running slower than it was when I had it as a DHCP and NAT(with the error). However that could just be me going crazy
 

Altemose

macrumors G3
Mar 26, 2013
9,089
444
Elkton, Maryland
@willydimes If it speed tests slower then switch back to DHCP & NAT and add the AirPort to the DMZ of the other router. Creating a private network name will do you little good in terms of security and privacy as all traffic still goes through the other router. I would set up the AirPort with matching settings that way devices can connect to either the main router or the AirPort depending on proximity and signal strength and switch freely.
 

dyt1983

macrumors 65816
May 6, 2014
1,358
143
USA USA USA
I was just planning on the TC being its on private name. I switched it over to bridge mode and now no error but it seems to be running slower than it was when I had it as a DHCP and NAT(with the error). However that could just be me going crazy
If you thought the performance was better with double NAT and you didn't have any other issues, just go in to Airport Utility and ignore the error. Green light.
 

Altemose

macrumors G3
Mar 26, 2013
9,089
444
Elkton, Maryland
If you thought the performance was better with double NAT and you didn't have any other issues, just go in to Airport Utility and ignore the error. Green light.
Double NAT can cause issues with applications using specific ports. A way to get past this is to utilize the demilitarized zone on the main router.
 

dyt1983

macrumors 65816
May 6, 2014
1,358
143
USA USA USA
Double NAT can cause issues with applications using specific ports. A way to get past this is to utilize the demilitarized zone on the main router.
Maybe you misread part of my post? The part about "didn't have any other issues". If you have issues, don't use the double NAT.

DMZ can cause issues with machines not behind the AirPort. A way to get past this is to utilize the bridge mode on the AirPort.
 

Altemose

macrumors G3
Mar 26, 2013
9,089
444
Elkton, Maryland
Maybe you misread part of my post? The part about "didn't have any other issues". If you have issues, don't use the double NAT.

DMZ can cause issues with machines not behind the AirPort. A way to get past this is to utilize the bridge mode on the AirPort.
No. I did not misread your post at all. You did not state the potential consequences of a double NAT configuration. While ignoring the error may fix the problem now, you don't know if OP would have an issue with an application not working in the future because of the double NAT configuration. It throws a warning for a reason and should only be ignored if resolved fully (e.g. adding the AirPort to the DMZ, setting modem to bridge mode, etc.).