ISP automatic forums » PHONE POWER → Westell 6100F act as routers in bridge mode

Been having random quirks with the Grandstream on&off such as having to reboot every now and then, lack of registration, not getting new firmware updates. Worked on&off with them for a year but could never pin it down to anything specific? Well yesterday everything fell into place, Dave found out that even though my modem a 6100F is in "bridge mode" it is not completely bridged. It still has its own gateway and private IP. So I'm looking to buying a Westell 2100 or 2110 that is a "dumb modem". If no one responds at DSLR I'll pick one up online. Thanks Dave, Kitt, Matt, Shaun, and anyone who I missed... My phone has more power!

Here is the email from Dave...wanted to share it because it may help others that might be having similar problem(s) with modems acting like routers and making PP act quirky. Thanks

Here is the evidence that your modem is not fully bridged, and is in fact still actively doing something other than modulation/demodulation. When accessing our device via telnet using a command prompt we told it to announce its status. Notice the subnetmask and default gateway - the mask contains all network octets, no host octet. The gateway consists of a PRIVATE non-routable IP address, even though the actual IP address is a public IP. This suggests the device is not actually bridged but it doing some sort of IP passthrough in lieu of an actual bridge mode. This is why you have experienced the random issues with your traffic, and why I had to wrestle with the device to get it to receive a config file. Several times it failed as shown in my syslog reporting from the device, I think it was about 5 attempts before the modem finally allowed it to pass through unobstructed. Hope this helps.

Grandstream HT-502 V1.1C Command Shell Copyright 2006-2008
Password:
GS> status
Product Model: HT-502 V1.1C
MAC Address: 00:0B:82:1E:39:28
Network:
IP Address -- 96.xxx.x.xxx
Netmask -- 255.255.255.255
Gateway -- 10.xx.xx.x
DNS Server -- 4.x.x.x
DNS Server -- 0.0.0.0

The 6100F can be put in real bridge mode -- just set both Protocol and bridge mode to 'bridge'. See »Router to use for westell 6100F? .

Of course, when you do this, you need to set up whatever device is connected to the modem (router, ATA, PC) with your PPPoE credentials.

The behavior Dave reported indeed violates RFC 2132 section 3.5. However, many modems work that way (when configured to do PPPoE on the modem, but provide a public IP to the connected device). Windows can deal with the errant behavior, but it won't work with Linux or Mac, let alone many embedded devices. It's very difficult for a modem to do the right thing in this situation, though some Speedstream units are compatible with most OSes. I'll suppy some technical details if Dave is interested.

Thanks for the heads up Stew I did some Googling and
came upon this. »Verizon DSL FAQ »How do I use a router with the Westell 6100?

When I bridged, I may have not disabled the DHCP server?
So I just went through a little hassle to reset the modem and hook it directly to the computer. Followed the directions to a T, plugged the modem back into the Gulfstream, :P then plugged the long cord from the router back into the Gulf. Just talked to Brain and indeed still getting a private Gateway. So it is off to Amazon.com.