Motorola SBG900 wireless cable modem (Solved)

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Flash
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Motorola SBG900 wireless cable modem (Solved)

#1 Post by Flash »

I only started using this modem today. I'm using it with the ethernet connection, not the wireless, until I think I have it configured right.

When I booted multisession Puppy Dingo 4 this morning it automatically connected to the internet via a DSL modem, which various Puppys have been doing without any problem for over a year. After a few hours I switched the ethernet cable to the Motorola cable modem and told Puppy's "connect" wizard to get a new IP address with DHCP. I didn't shut down the computer or reboot Puppy before I switched modems. It worked and I was back online via the cable modem within a few seconds. I logged back into my Yahoo mail and checked the Puppy forum, then left for a while. When I came back, the browser would not renew any web page or connect to a new website. It just sat there spinning until it timed out.

The browser started working again when I told the connect wizard to get a new IP address with DHCP. This has happened several more times since.

Can anyone explain what's going on? I don't believe the modem is losing the connection with the ISP, I think Puppy, or SeaMonkey, is somehow losing the connection to the router. I've poked around in the router (gateway, as Motorola calls it) configuration but can't find anything that looks like it might be the cause. I called Motorola tech support. The guy I talked to had at least heard of Puppy Linux, but he doesn't have any idea why this is happening. Neither does Cox technical support. :?
Last edited by Flash on Sun 25 May 2008, 17:54, edited 1 time in total.

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nipper
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Re: Motorola SBG900 wireless cable modem

#2 Post by nipper »

Flash wrote:When I booted multisession Puppy Dingo 4 this morning it automatically connected to the internet via a DSL modem, which various Puppys have been doing without any problem for over a year. After a few hours I switched the ethernet cable to the Motorola cable modem and told Puppy's "connect" wizard to get a new IP address with DHCP. I didn't shut down the computer or reboot Puppy before I switched modems. It worked and I was back online via the cable modem within a few seconds. I logged back into my Yahoo mail and checked the Puppy forum, then left for a while. When I came back, the browser would not renew any web page or connect to a new website. It just sat there spinning until it timed out.

The browser started working again when I told the connect wizard to get a new IP address with DHCP. This has happened several more times since
Here is something for you to consider.

On broadband connections, ISPs often tie the DHCP to a specific MAC address. with just a "modem" when your box asks for IP it does so with the MAC of your interface card. Gateways (modem, NAT router combinations) have their own WAN (outward, Internet) interface with it's own MAC. In theory, when time comes to renew the lease, the gateway tries with its own wrong MAC (wrong in the list that the ISP server has for that account) and thus it does not receive the new lease. Have you noticed any consistency to loss of connection, could it be expiry of lease time? When your box asks for the lease, it sends the correct MAC (in the list). If this is the case there are two ways to correct. Call the ISP and deal with what is usually inept assistance or just refusal because they don't support Linux, or look in the router configuration for a place where you can select to "clone the MAC" (or something like that). Doing that lets the router spoof the MAC of your box that your ISP has on record for you.

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Flash
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#3 Post by Flash »

Thanks for your reply.

Naturally I forgot to mention in my original post that I had to tell Cox cable (my new ISP) the MAC address of the modem before it would connect to the internet.

Last night I e-mailed Motorola technical support, with a link to this topic. The good news is, I got a reply today; the bad news is, it was completely useless boilerplate. I doubt that whoever answered even bothered to read what I wrote.

I have Windows 2000 installed on this computer. I guess I'll have to risk connecting it to the internet, to prove that the problem only occurs with Puppy. I can see that this is going to take a long time, if it ever gets solved. :(

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nipper
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Re: Motorola SBG900 wireless cable modem

#4 Post by nipper »

Flash wrote: I don't believe the modem is losing the connection with the ISP, I think Puppy, or SeaMonkey, is somehow losing the connection to the router. I've poked around in the router (gateway, as Motorola calls it) configuration but can't find anything that looks like it might be the cause.
That is something you can test. The gateway will have a LAN interface IP address, this is the gateway IP and you can try a ping to it to establish if you are still connected. That could help you isolate the loss of connection further and prove your theory.

Often one can see a lot by watching the lights on the interface cards and gateway. For example, does it still show a WAN link when you can't connect from Puppy?

The only other thing which has occurred to me so far is that somehow your system loses the nameserver address and needs a pump to reassign it but I can't think of a way for that to happen. It doesn't seem likely. Have you tried to surf with IP addresses rather than domain name? I have seen gateways which have a setting to pass or not pass DNS information through but I'm not familiar with the particulars of that and I've only ever tried enabling that, don't know what would happen if it's disabled.

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Flash
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Re: Motorola SBG900 wireless cable modem

#5 Post by Flash »

nipper wrote:
Flash wrote: I don't believe the modem is losing the connection with the ISP, I think Puppy, or SeaMonkey, is somehow losing the connection to the router. I've poked around in the router (gateway, as Motorola calls it) configuration but can't find anything that looks like it might be the cause.
That is something you can test. The gateway will have a LAN interface IP address, this is the gateway IP and you can try a ping to it to establish if you are still connected. That could help you isolate the loss of connection further and prove your theory.
Thanks, I'll try that.
...Often one can see a lot by watching the lights on the interface cards and gateway. For example, does it still show a WAN link when you can't connect from Puppy?
I think all the lights stay lit all the time, even when the browser just sits and spins. I'll pay close attention at noon.

Here's another clue: the connection seems to drop if I don't do anything online for a while. It stays up as long as I'm doing something online. This morning I left the computer on but idle for less than an hour while I walked my dog. When I returned, I had to tell the connect wizard to get an IP address before the browser would refresh the Puppy forum page.
The only other thing which has occurred to me so far is that somehow your system loses the nameserver address and needs a pump to reassign it but I can't think of a way for that to happen. It doesn't seem likely. Have you tried to surf with IP addresses rather than domain name? I have seen gateways which have a setting to pass or not pass DNS information through but I'm not familiar with the particulars of that and I've only ever tried enabling that, don't know what would happen if it's disabled.
Well, all I have to do to get back online is "refresh" my IP address with DHCP.

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nipper
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Re: Motorola SBG900 wireless cable modem

#6 Post by nipper »

Flash wrote:I think all the lights stay lit all the time, even when the browser just sits and spins. I'll pay close attention at noon.
Well, if the light on the port for your wired connection stays on, that is supposed to indicate a link (connection), is the light on the ethernet interface of your computer on too?
Flash wrote:Here's another clue: the connection seems to drop if I don't do anything online for a while. It stays up as long as I'm doing something online. This morning I left the computer on but idle for less than an hour while I walked my dog. When I returned, I had to tell the connect wizard to get an IP address before the browser would refresh the Puppy forum page.
OK, so it does seem to be periodic, one possibility that we haven't explored is the lease time for your LAN optioned in the gateway. It might be interesting to compare the lease time and the amount of time the connection stays up. It should renew the lease automatically though.

It might be interesting to also compare the lease times for the connection to the ISP in the gateway to see if the "period" of your dropped connection compares to this lease time.
Flash wrote:Well, all I have to do to get back online is "refresh" my IP address with DHCP.
Some time before you do that refresh do an ifconfig -a to see the interfaces in your computer. We can check if it still has the IP address.

The lights on the gateway can show you quite a bit. For example, if you make a request to refresh the forum page, you should be able to see the link light (for your connected port) blink (data transmission) and very soon the WAN would blink too on a working connection. With luck you might be able to tell visually how far your request is getting.

Another method could be to try to get to the gateway setup pages while the connection won't surf, that could prove your connection between the gateway and your machine and once at those pages you can check to make sure the gateway still has an IP assigned from your ISP.

One thing I'd like to do at this point is try another computer on this setup to see if it behaves the same or differently. I know that isn't always possible.

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Flash
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Re: Motorola SBG900 wireless cable modem

#7 Post by Flash »

nipper wrote:... if the light on the port for your wired connection stays on, that is supposed to indicate a link (connection), is the light on the ethernet interface of your computer on too?
Yes. As far as I can tell, the lights stay the same all the time, except the PC/activity light on the modem flickers when the light on the computer flickers. This computer has no light on the ethernet port, only one idiot light that flickers to let you know that the computer is doing something. Or not. :roll:
... one possibility that we haven't explored is the lease time for your LAN optioned in the gateway. It might be interesting to compare the lease time and the amount of time the connection stays up. It should renew the lease automatically though.

It might be interesting to also compare the lease times for the connection to the ISP in the gateway to see if the "period" of your dropped connection compares to this lease time.
Here's some info I copied from the gateway's configuration when it wouldn't refresh webpages:

Code: Select all

This page lists the status information for several gateway configuration parameters. 			
			
null
		WAN Status 			Data 	
		WAN IP Address 			72.222.135.21
		DNS Address 1 			68.105.28.11
		DNS Address 2 			68.105.29.11
		DNS Address 3 			68.105.28.12
		TCP Session Wait Timeout 			300 seconds
		UDP Session Wait Timeout 			300 seconds
		ICMP Session Wait Timeout 			300 seconds

		LAN Status 			Data 	
		LAN IP Address 			192.168.0.1
		LAN Subnet Mask 			255.255.255.0
		MAC Address 			00:1E:46:E9:E7:A1
		DHCP Server Enabled 			Yes

	DHCP LEASE TABLE 	
		IP Address 			MAC Address 			Hostname 			Method 			Lease
Create Time 			Lease
Expire Time 	
		192.168.0.10 			00:40:CA:28:FE:06 			puppypc 			Dynamic 			2008-05-24 09:23:28 			2008-05-24 10:23:28 	


	TRANSLATED ADDRESS 	
		WAN IP Address 			WAN Port 			LAN IP Address 			LAN Port 			Mapping Mode 			Mapping Protocol 	
		72.222.135.21 			55349 			192.168.0.10 			55349 			2 			4 	
		72.222.135.21 			55935 			192.168.0.10 			55935 			2 			4 	
		72.222.135.21 			35638 			192.168.0.10 			35638 			2 			4 	
		72.222.135.21 			34678 			192.168.0.10 			34678 			2 			4 	
		72.222.135.21 			44311 			192.168.0.10 			44311 			2 			4 	
		72.222.135.21 			48876 			192.168.0.10 			48876 			2 			4 	
		72.222.135.21 			57903 			192.168.0.10 			57903 			2 			4 	
		72.222.135.21 			35643 			192.168.0.10 			35643 			2 			4 	
		72.222.135.21 			44315 			192.168.0.10 			44315 			2 			4 	
		72.222.135.21 			44540 			192.168.0.10 			44540 			2 			4 	
		72.222.135.21 			35645 			192.168.0.10 			35645 			2 			4 	
		72.222.135.21 			35647 			192.168.0.10 			35647 			2 			4 	
		72.222.135.21 			36940 			192.168.0.10 			36940 			2 			4 	
		72.222.135.21 			35384 			192.168.0.10 			35384 			2 			4 	
		72.222.135.21 			35650 			192.168.0.10 			35650 			2 			4 	
		72.222.135.21 			44322 			192.168.0.10 			44322 			2 			4 	
		72.222.135.21 			57267 			192.168.0.10 			57267 			2 			4 	
		72.222.135.21 			39851 			192.168.0.10 			39851 			2 			4 	


	PASSTHROUGH HOST 	
		Passthrough MAC Address
... do an ifconfig -a to see the interfaces in your computer. We can check if it still has the IP address.

Code: Select all

# ifconfig -a
ath0      Link encap:Ethernet  HWaddr 00:18:02:3A:52:64  
          BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

eth0      Link encap:Ethernet  HWaddr 00:40:CA:28:FE:06  
          inet addr:192.168.0.10  Bcast:192.168.0.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:11554 errors:0 dropped:0 overruns:0 frame:0
          TX packets:11331 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:12305442 (11.7 MiB)  TX bytes:2136407 (2.0 MiB)
          Interrupt:10 

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

wifi0     Link encap:UNSPEC  HWaddr 00-18-02-3A-52-64-00-00-00-00-00-00-00-00-00                                                              -00  
          BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:199 
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)
          Interrupt:10 

# 
The lights on the gateway can show you quite a bit. For example, if you make a request to refresh the forum page, you should be able to see the link light (for your connected port) blink (data transmission) and very soon the WAN would blink too on a working connection. With luck you might be able to tell visually how far your request is getting.
Yes, the "PC/activity" light on the modem flickers when the light on the computer flickers.
Another method could be to try to get to the gateway setup pages while the connection won't surf, that could prove your connection between the gateway and your machine and once at those pages you can check to make sure the gateway still has an IP assigned from your ISP.
See the above from the gateway configuration screen. If that isn't enough, there's lots more where it came from. :lol:
One thing I'd like to do at this point is try another computer on this setup to see if it behaves the same or differently. I know that isn't always possible.
It seems to me that the problem is in Puppy, perhaps is a subtle mismatch of the settings between the gateway and Puppy's TCP/IP control. I have no idea where to look for that, or what to do with it if I find it. I assume it's in the kernel somewhere. Of course, I'm probably going to be like the guy who overhauled his engine only to discover that the car wouldn't start because the gas tank was empty. :oops:

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#8 Post by Flash »

I think the problem is solved. It seems that the firewall in the Motorola SBG900 is so poorly thought out as to be worse than useless. I did the procedure recommended here (only without rebooting anything):
before we begin, im using windows XP but get timeout errors aswell. P bags i was on the phone to telstra technician before who was very helpfull and gave me a few tips on how to fix the problem. Firstly make sure that you are letting your modem take care of your internet connection and not the bigpond cable login (if you are using one). secondly you can bypass the inbuilt modem firewall. To do this make sure that you have uninstalled cable login client. Enter your details into the main modem page (bigpond tab). Reboot the modem, once it has finished rebooting, reboot your computer. Go back to modem page, click on the left hand side gateway, then select LAN tab. Under LAN tab there are three further tabs, select DHCP leases. At the bottom there should be a heading "current DHCP leases". MAKING SURE U CLICK THE BYPASS FIREWALL CHECKBOX copy and paste the information from current DHCP leases into the title above which says "reserve new ip address". click add. reboot modem, reboot computer. and there shoudln't be any more timeouts :)
and then left my computer on all night. This morning I was able to refresh the forum website and my Yahoo mail without first having to tell the connect wizard to refresh the IP address.
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mikeb
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#9 Post by mikeb »

Yo ..I do believe you just solved a problem for me...timing out on wireless...
I reserved addresses for all the wired machines which don't timeout when idle

off to try it out

cheers

mike

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