Posted: Tue Jun 29, 2010 17:35 Post subject: VLAN tagging greater than 15
According to this quite old post,
http://bit.ly/bHRZVC, it isn't possible to tag VLANs over 15. I was wondering then what is the "Setup", "Networking", "VLAN Tagging" and "Tagging" section. I have tried, as you can see in the attached file, to tag vlan10 and vlan11 with tag 800 and 801. I was thinking I could then trunk vlan10 and vlan11, and believed that the WRT54GL would tag them as 800 and 801. It doesn't work so far, is it a hardware problem, or a layer-8 problem related to my configuration and understanding of the tagging in DD-WRT?
My understanding of it (which could be wrong) is that the internal switch hardware is not capable of handling tags over 15 so you won't ever be able to send/receive any higher tags on Broadcom hardware. This is why the VLAN page only allows VLAN0-15. However, the linux kernel has no such limitation on the software side of things, and so it will happily tag whatever you want before it sends that traffic to the internal switch. Once the internal switch gets those high tags from the kernel or another device then it will throw them out. _________________ Read the forum announcements thoroughly! Be cautious if you're inexperienced.
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My understanding of it (which could be wrong) is that the internal switch hardware is not capable of handling tags over 15 so you won't ever be able to send/receive any higher tags on Broadcom hardware. This is why the VLAN page only allows VLAN0-15. However, the linux kernel has no such limitation on the software side of things, and so it will happily tag whatever you want before it sends that traffic to the internal switch. Once the internal switch gets those high tags from the kernel or another device then it will throw them out.
interesting though that the default firmware for say the dir-880l does vlan tagging just fine. but in ddwrt it limits it to 15?
