IP address assignment by ISP vs. router/modem

IP address assignment by ISP vs. router/modem
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penguin99 @ 7th Oct 04:12AM:
IP address assignment by ISP vs. router/modem

A few months ago, I wanted to change my modem's Wifi passwords and other settings. To do this I had to enter this address in my browser: »10.0.0.1 (or something similar)

I could not access the modem's configuration via this address. I have used this modem for 3 years and had no problems changing the configuration in the past.

I then ran IPCONFIG and saw an unusual result - the default gateway did not show the 10.0.0.1 address for the modem (as I remembered from the past). Instead, it showed an IP address as if it had been assigned by the ISP.

I hit the hard reset button on the modem to restore all the default settings and talked with tech support to get the correct connection settings. After doing this, I was able to see 10.0.0.1 as the default gateway and could access the modem configuration menu. But after a few minutes, the address was changed and I could no longer access the config menu.

What's going on here? It's as if the modem's gateway/local routing function stopped working and just directly connected my pc to the isp, which assigned addresses to each of my local pc's. Is my modem flaky?

I am using a Zoom ADSL X6 dsl modem with wifi + 4 lan ports.
I got this modem several years ago when I signed up with Sonic, then continued to use it after signing up with DSL Extreme. They said it was an unsupported model, but it seems to work.
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dslx_gm @ 12th Oct 10:04PM:
Re: IP address assignment by ISP vs. router/modem

Hi penguin99 -

Based on what you described above it appears that the modem is configured in half bridge mode. Are you on a PPPoE based connection or DHCP based connection?

I am not intimately familiar with that modem but you may need to enable routing on the modem. Resetting the modem may have turned it back into bridge or half bridge mode.

Thanks
--
George
General Manager
DSL Extreme
Will work for reviews. ;)
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penguin99 @ 10th Nov 06:39PM:
Re: IP address assignment by ISP vs. router/modem

I think it is a DHCP based connection.

I'm not familiar with the terms bridge or half bridge mode. Can you explain?
Is the crux of the problem the modem not functioning as a router and therefor unable to assign IP addresses to each computer?
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dslx_gm @ 10th Nov 08:06PM:
Re: IP address assignment by ISP vs. router/modem

A modem in bridge mode means that it doesn't have any routing functions. It only purpose is to create the connection between the DSLAM and it. Half bridge is essentially the same thing but it allows you do to PPPoE authentication in and pass through the WAN IP. It doesn't do routing or hand out internal IP addresses.

If you wanted the modem to hand out internal IP addresses you would need to set it as a router.
--
George
General Manager
DSL Extreme
Will work for reviews. ;)
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