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DylanG · Apr 30, 2005, 12:43 PM

I thought this deserved it's own thread...

Right now I've got Panther on the internal drive of my PB and was using a firewire drive to test Tiger. Both worked fine at home with my Airport Express.

Today I come to the local coffeeshop and Panther works fine but Tiger won't get a DHCP address. I could make Tiger work by manually specifying the IP settings but not with DHCP. I found a post here, shortened my computer name and now it works. This looks like a Tiger bug with (some? all?) non Apple wireless routers. They have a DLink 624 at the coffee shop.

JohnCoffee · Apr 30, 2005, 12:53 PM

How long was your name when it didn't work and to what length did you shorten it?

DylanG · 01:30 PM

I changed it from 25 to 17 characters. Both have an apostrophe and embedded spaces.

surferboy · Apr 30, 2005, 01:22 PM

This is definately true. I had the same issue with the same solution.

DylanG · Apr 30, 2005, 01:27 PM

Yes

, it was surferboy's post that gave me the solution

surferboy · Apr 30, 2005, 01:33 PM

Dylan, glad you got it working. Hopefully our struggles will save a little hassle for some others....

DylanG · Apr 30, 2005, 01:51 PM

I've determined the maximum length allowed to be 20. I don't know if that is universal or specific to the DLink 624. I scanned the DHCP spec and didn't see any mention of a maximum length for this value. But it appears that Panther truncated this name and Tiger does not.

DylanG · Apr 30, 2005, 07:12 PM

I found the appropriate section of the DHCP spec and the client name is a variable length field with no length restriction. This appears to be a bug in the DLink 624. There have been a number of firmware updates for that router that fixed vaguely worded DHCP problems.

My guess is that Apple restricted this length in Panther to avoid what appears to be a somewhat common problem. Perhaps the removing this restriction was an oversight or they felt that they could count on properly function DHCP servers.

I even sniffed the wireless connection while it's renewing DHCP lease and what Apple sends is correct for longer and shorter computer names. I already blew away my Panther install so I can't see what it sends. If anyone has a sniffer like Ethereal installed under Panther I'd be curious to know.

OreoCookie · Apr 30, 2005, 07:38 PM

Try to avoid apostrophes and stuff like this. Routers are small computers running Linux or *BSD, and in the Unix world, the apostrophe has a special meaning. Usually short names without spaces are the safe bet.

DylanG · Apr 30, 2005, 08:42 PM

In general good advice but I've confirmed that the apostrophes and spaces are removed or converted to legal chars for the network name.

OreoCookie · Apr 30, 2005, 09:01 PM

Originally Posted by DylanG

In general good advice but I've confirmed that the apostrophes and spaces are removed or converted to legal chars for the network name.

Yes, I know. But this way, you avoid having several versions of your machine's name floating around. (You can check the conversion in the sharing pref pane, it shows you the name your machine has in your network.)

Kristoff · May 1, 2005, 12:09 AM

the fact is, the only legal characters for host names are:

a-z
0-9
and the '-'

everything else, including the '_' are not legal hostname characters per RFC952.

So, any hostname with spaces, apostrophes, and suchlike are just begging for trouble.

Now, if you ask me, the fact that Apple defaults hostnames to those ridiculous strings like:

"Steve Job's Computer" now, that's the real bug as it's not RFC952 compliant!