My TC keeps getting assigned a wrong IP (out of range)

Hello,

Just this morning I started to experience the following issue. Everything was working well until this morning with the following setup:

The setup:

• I have an ADSL modem (wifi disabled), that is connected to Air Port Time Capsule 3 TB (purchased just 1 month ago, with the latest firmware installed) with LAN cable.
• The modem's local IP is 192.168.1.1
• Its subnet mask is set to 255.255.255.0
• It is assigning IPs to devices (there is only one device connected to the modem, which is the Time Capsule (TC)) via DHCP.
• DHCP range is 192.168.1.4 to 192.168.1.99
• I have been using TC as the main access point (all other wireless and wired devices are connecting to internet using TC) in bridge mode.

The problem:

Since today morning, although they are connected to TC my devices could not connect to internet.

When I check Airport utility, it shows that:

- TC is not connected to internet (the circle is orange)

- It is assigned to a weird IP (169.254.33.41) and Subnet Mask (255.255.0.0) which are different than the modem's DHCP settings.

When I check the modem via modem admin interface everything seems ok and it is actually connected to internet. To make sure I re-enabled the modem's wifi and connected my Macbook directly to the modem over wifi, and I was able to connect to internet. When I checked the assigned IP of Macbook it was well in the range (192.168.1.xx). After this test I disabled the wifi of the modem again.

Failed attempts to solve the problem:

1) I restarted the modem, gave a hard reset to TC, and configured it again via Airport utility got the same issue.

2) I tried to disable the bridge mode and set TC as a router (assigning IPs via DHCP). This time TC gave "Double NAT" error. I don't know what it means but then I disabled the modem's NAT and restarted the TC but got the same problem.

3) I went back to the bridge mode. I set manual IP (192.168.1.99) and subnet mask to TC (255.255.255.0) and applied settings. Airport utility showed everything well and working (the circle is green) but this time I wasn't able to connect my Macbook to internet. When I ckecked the assigned IP of Macbook it was that weird IP range (169.254.33.xx) and weird subnet mask.

Could you please help me to identify the problem?