The DNS-323 can support 802.1q vlans/frame tagging. The native kernel does not support this, however. To make it work, you must load an 8021q.ko kernel module into your kernel. You should have a chroot debian install to accomplish this. I will spare you the trouble of having to compile the module yourself.
Here is a link to the file: 8021q.ko. Warning: I have only tested this with firmware 1.06, but may work with earlier versions. Use at your own risk!
One reason you may want to do this is that you want to configure jumbo frames for (potentially) faster DNS-323 performance, but don't want to/can't activate jumbo frames on your primary network because some devices don't support it. (Jumbo frames require a Gigabit switch, but not all Gigabit switches and NIC's support jumbo frames)
#Put the file in the proper location sudo mkdir /lib/modules/2.6.12.6-arm1 sudo cp 8021q.ko /lib/modules/2.6.12.6-arm1 sudo depmod -a #Load the module into the kernel sudo modprobe 8021q #Install the vlan package - This enables management of vlans sudo apt-get install vlan #Use the vconfig command to configure a new trunked sub-interface sudo vconfig add egiga0 <vlan number>
Use sudo ifconfig to configure your new interface. It should appear as egiga0.<vlan>. Don't forget to bring the interface up!
Be sure to save the config steps to your fun_plug or linuxrc file (after you test this first!) so this is persistent across reboots.