[MLB-WIRELESS] [OT] Vista desktop can no longer connect to Internet via Netgear CGD24N cable gateway

Michael Borthwick holden at netspace.net.au
Thu Oct 27 19:37:45 EST 2011

On 26/10/2011, at 10:00 AM, Daniel Carosone wrote:

> On Tue, Oct 25, 2011 at 20:39, Michael Borthwick <holden at netspace.net.au 
> > wrote:
> I hope you'll pardon the off topic post.
> At a client site an on Friday a 3 year old Acer Aspire M1610 desktop
> running Vista was working fine and on Monday morning was unable to
> connect to the Internet.
> Specifically it does not get a lease from the cable modem router
> whether set to "obtain in IP address automatically" or when manually
> set within the range of addresses the router allocates by default
> (which is the entire 192.168.0.x subnet).
> not sure why this would be..
> I have put the PC NIC on a 10.10.0.x subnet connected to eth3 of a
> MicroTik RouterBOARD 532 and put eth2 of the MicroTik on the cable
> modem routers 192.168.0.x subnet and created a route between them. The
> MicroTik gets a lease but the PC still cannot connect to the Internet
> (it still shows up as unidentified network) although the PC can ping
> the router at
> So, you have evidently demonstrated that the pc's ethernet still  
> works, which is one thing.  Note, however, that unless you had a nat/ 
> masquerade rule in the 532 for the PC, this could have prevented  
> proper internet access.  It's not entirely clear where the route you  
> added was, but note that even if the netgear has a route to  
> 10.10.0.x, it may not NAT such sources out to the internet.
> If I'm right, perhaps knowing exactly what happened in this test  
> will help you isolate the real problem.
> I have reset the cable modem router to factory defaults in case it has
> stored some kind of exception to the MAC of the PC even though I was
> cloaking this behind the RouterBOARD
> As above, it may have been a different issue at that point.
> Whirlpool says that the Netgear CGD24N is a bjorked device especially
> for a small business (there are around a dozen wired clients on a
> Cisco switch) and up to half-a-dozen iOS devices at various times. It
> does need to be reset a lot - however after a return to factory
> defaults it is hard to believe it can be fault and all other wired and
> wireless devices are OK, at least for the time being.
> I'm guessing it's a windows problem rather than with the router,  
> especially if other devices are working fine.  Can't really be more  
> specific than that, though
> I've exhausted my trouble-shooting abilities - particularly on the
> Windows side. Is there some other layer in the Windows OS that could
> be holding it down ? I really don't know where else to look or what to
> try.
> At this stage I'm considering.
> 1. Buyng a new NIC even though the built in one seems fine from a
> hardware POV to see if the "unblocks" it.
> 2. Reinstall Vista from the backup image on the HD.
> Boot something else from a livecd and verify the hardware, to start  
> with.  Then at least you have confirmed a software issue on the PC.   
> That could be anything from bad/accidental config to malware.

Thanks Daniel and Adam,

With the RouterBOARD 532 now properly configured as an intermediary?  
router with a dhcp-client on ether2 facing the Netgear and a dhcp- 
server on ether3 facing the PC in question the PC can access the  
Internet whether running Vista or when booted from SystemRescueCd, a  
Linux system rescue disk http://www.sysresccd.org/

When the RouterBOARD is removed and the PC is directly connected to  
the Netgear CGD24N cable modem router (via the Cisco switch)  the PC  
cannot get a lease and access the Internet regardless of whether it is  
booted into Vista ***OR*** Linux ...


More information about the Melbwireless mailing list