Re: [Sheflug] D-Link DSL 300T/OpenBSD3.7/SuSE 9.2

[lesleyb <lesley.binks [at] xxxxxxxxx>]

lesleyb wrote:
> Hello
>
> Thought I'd relate this tale.
>
> My ISP went off line yesterday but came back up at 11.59:43 according to 
> my D-Link DSL 300T modem.
>
> What was very strange is that I could get no route out.  I checked my 
> Internet facing box (OpenBSD) and it was getting real upset with 
> arplookup and arpresolve errors and all sorts of mayhem resulted when I 
> tried restarting the OpenBSD network via a 'sh netstart', or soft 
> rebooting or hard rebooting.  Effectively it was saying it already had 
> the IP address the modem was trying to give the NiC.
>
> Now, I did have that D-Link set to *not* use DHCP but, for some reason 
> it decided it should DHCP when iot regained the cionnection from the 
> ISP.  Depsite being able to access the configuration pages, and 
> reconfiguring the modem to not use DHCP I was still seeing arplookup and 
> arpresoolve errors on the OpenBSD box and still getting errors 
> indicating the card wouldn't accept the internet address the modem was 
> trying to give it, again trying with 'sh netstart' a soft reboot and a 
> hard reboot in the OpenBSD box.
>
> Things got more interesting: I could connect to the modem's interface 
> via the LAN, and over my LAN I could observe the traffic on the NiC 
> connected to the modem.  I had no route out; I got messages back from 
> the modem telling me the modem could not find the DNS servers, but it 
> the modem's system log the DNS servers were listed and correlated with 
> the DNS servers I have listed on my side.  (I'm working on running DNS 
> here.)
>
> Despite several attempts to get the network up and running using either 
> a fixed IP address or DHCP on the OpenBSD box no joy whatsoever.
>
> So I unplugged the modem from the OpenBSD box and stuck it on the SuSE 
> box, set the Suse NIC to DHCP and the default route to my fixed IP 
> address.  I did this via YaST2->Network Devices.
<snip>
> The outage occurred in the middle of my netinstalling Debian onto my 
> laptop.  I'm not sure what the God(s) have got against me having Debian 
> ( ;-) ) but this is the second time I have experienced problems outside 
> my control when installing Debian on one of my machines.
>
>
> Regards
>
> L.

I've sorted out more of what was going on with the SuSE routing 
'problem'.  This may be a recap of the previous post, but I think it's 
questionable whether it's a bug or a feature.

Using the YaST2 -> Network Devices->Network Card interface I had 
previously set up a static route via my normal network.  This included a 
static IP address for the NiC on the box and a static default route.

The D-Link created mayhem on my Internet facing BSD box, despite my 
setting the interface to DHCP.  I'm happy to put this down to my 
relative inexperience with controlling routing in BSD and not a BSD 
fault.  I didn't do a route flush before restarting the network for 
example and unsurprisingly routed banged on about duplicate IP addresses.

So I took down the static route on the SuSE box by selecting the DHCP 
button and deleting the static route I'd set up.

This may be considered a bug by some and a feature by others, but all 
the static routing information is left in 
/etc/sysconfig/network/ifcfg-eth0-<mac address here> .

This information then interfered with manually setting up the routing 
tables for the new configuration using ifconfig and route.  The netmask 
for the static route still came into play for instance.

Deleting all references to any static route information from 
/etc/sysconfig/network/ifcfg-eth0-<mac address here> stopped this from 
happening.

The D-Link refused to stop DHCP'ing, disregarding any setup I gave it 
via the web interface.

This unit has now been replaced by a ZyXel which is operating well and 
survives power cycles and disconnection of ethernet cables without 
losing it's settings.  I have managed to finish installing Debian on my 
laptop.

The DSL 300T is known to be a bit problematic, which is a shame because 
it's one of the few single port Ethernet ADSL modems out there.

*However all reports show that D-Link will replace offending units*

I may not or may not be taking that option because I have discovered 
certain 'undocumented features' so it may become a toy, possibly a very 
shortlived toy but a toy all the same.

For the curious it runs Busybox v0.6

L.



___________________________________________________________________

Sheffield Linux User's Group -
http://www.sheflug.co.uk/mailfaq.html

 GNU the choice of a complete generation.