D-Link DSL-G664T: Problems and Solutions

I got this new Router/Access Point/4Port Switch/ADSL-Modem from the german ISP Freenet. This is their setup guide.

Here is a quick summary of the problems and their solution and of firmware bugs I found (which are hopefully fixed in the next firmware release). The stuff may also apply to the DSL-G604T.

WEP configuration

Update: This bug seems to be fixed in firmware V1.00B02T02.EU.20040721.

Several browsers seem to have problems with the Setup->Wireless form. Some tests show that KDE Konqueror (V3.1.4) under GNU Linux and Internet Explorer (V5.50) under Win2K are working, while Mozilla 1.6 and Mozilla FireFox 0.8 under GNU Linux are not able to change the WEP keys.
Anyway, if you try to configure a WEP encryption key under Setup->Wireless, you must fill out all four "Encryption Key" fields. If you only fill one field (as I did first), the web interface will not accept your entries.
Note that the changes become active immediately, so you should either configure WEP via cable connection or change your computers WEP configuration after you have changed the configuration of the access point. Don't forget to save the configuration via Tools->System Commands->Save All.

SSH bug

The router will not let through SSH connections. See this page for a solution under GNU Linux.

DNS proxy bug

The DNS proxy on the router seems to be buggy. The reverse lookup of hosts containing a dash (-) in the host- or domainname does only work the first time. When the DNS proxy reads the information from it's cache, it will drop everything from the first dash, i.e.:
# host domain name pointer hal6000.thp.Uni-Duisburg.DE.
# host domain name pointer hal6000.thp.Uni.
This behavior will cause trouble with programs which rely on reverse lookup, e.g. ssh.
One workaround is to define static DNS servers on the clients or to use a local caching DNS server. A more sophisticated workaround is to save the router configuration to a file with Tools->Update Gateway->Configuration Backup and to edit the resulting XML file. Change the string <dns1></dns1> to <dns1>a.b.c.d</dns1>, where a.b.c.d is the IP address of your favorite DNS server, and restore the configuration. Then the router will supply DHCP clients with the DNS server a.b.c.d.

Update: This workaround does not work since firmware 1.00B02T02.EU.20040701 :-(

Telnet access


Defining own firewall/NAT rules

Update: This bug is fixed in firmware V1.00B02T02.EU.20040607.

If you want to define own firewall/NAT rules under Advanced->Port Forwarding->User, you must start the rule's name with a digit, else you will get the JavaScript Error "A name can not start with a number". This is a funny bug in the error checker...
I use a rule named "SSH_Server" to allow SSH access from the outside. It reads "Protocol TCP, Port Start 22, Port End 22, Port Map 22".

Last change: 22.7.2004