How do I correctly configure TFTP?

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Level 4

2,070 points

How do I correctly configure TFTP?

Hi again!

Now that I'm talking to my serial device, I need to provide it with a TFTP server (on an Ethernet) from which it can install its firmware. OS X, being UNIX, should be perfectly capable of running such a server. So, I looked around, found the xinetd and xinetd.conf man pages, set 'enable = yes' in /private/etc/xinetd.d/tftp, verified that /usr/libexec/tftpd exists, put the files to be served in /private/tftpboot, poked a hole in my firewall for port 69, and rebooted.

No joy. Using the Console utility to view the system.log, I do see xinetd starting tftpd in response to requests from my device's IP-address -- so it appears that the requests are getting through the firewall and are recognized by xinetd, and it is starting tftpd. However, the client on the device is claiming that the connection is timing out (in its cryptic way -- it is saying ' T'), and it is retrying every 5 seconds.

I can't see a way to get any more detailed information from tftpd about the problem. Has anyone successfully set up the stock OS X xinetd/tftpd ? Is there some step I'm obviously missing? Does anyone know how to get details of errors tftpd encounters?

Thanks!

Powerbook G4 1GHz

Posted on Mar 16, 2008 3:43 PM

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Answer 1

Karl Zimmerman Author

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Mar 16, 2008 4:08 PM in response to Karl Zimmerman

Just to avoid unnecessary confusion -- in /private/etc/xinetd.d/tftp, I set "disable = no" (not "enable = yes")...

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Answer 2

Karl Zimmerman Author

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2,070 points

Mar 16, 2008 4:13 PM in response to Karl Zimmerman

The same problem occurs when I use the OS X tftp client to try to download a file from /private/tftpboot; so it appears to be a problem with the server configuration. FWIW, I'm running 10.3.9...

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Answer 3

Karl Zimmerman Author

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Mar 16, 2008 4:19 PM in response to Karl Zimmerman

And yes, /, /private, /private/tftpboot, and /private/tftpboot/* are all world-readable...

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Answer 4

Karl Zimmerman Author

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Mar 16, 2008 4:38 PM in response to Karl Zimmerman

... and I forgot to mention that I did indeed do '/sbin/service tftp start'...

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Answer 5

Mar 16, 2008 9:06 PM in response to Karl Zimmerman

You got me curious. I too run Panther so I did what you described plus this:
http://www.netbsd.org/docs/network/netboot/tftpd.html#macosx
and I'm timing out also.
penn$ tftp tftpserver.test.net
tftp> get COA8O1OA.SUN4C
Transfer timed out.

tftp> get COA8O1OA.SUN4C
Transfer timed out.

tftp>

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Answer 6

Mar 16, 2008 9:34 PM in response to doug pennington

Karl, The above post was from server to 3rd party and below is from one of my machines to server.
dougsmachine:~ dougpennington$ tftp 10.0.0.13 69
tftp> get bs.txt
Transfer timed out.

tftp> get /private/tftpboot/bs.txt
Transfer timed out.

tftp> status
Connected to 10.0.0.13.
Mode: netascii Verbose: off Tracing: off
Rexmt-interval: 5 seconds, Max-timeout: 25 seconds
tftp> quit
And server log shows: START: tftp pid=762 from=10.0.0.14
Yeah, what is the deal on the time out, among other things? More Yahooing I guess. Doug

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Answer 7

Karl Zimmerman Author

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2,070 points

Mar 16, 2008 9:56 PM in response to doug pennington

Hey, Doug! Thanks for letting me know I'm not alone!
I've tried an AltaVista search, and have come up empty-handed.
I'll keep looking, too...

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Answer 8

Mar 16, 2008 11:17 PM in response to Karl Zimmerman

Uh Karl, I just now decided to look at home directory in both machines I have referenced, and the "get" files
I requested are in both machines home directories. Did another get for them, and sure enough they were replaced and re time stamped to reflect such. Guess the time out message is a code error or whatever? Doug

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Answer 9

Karl Zimmerman Author

Level 4

2,070 points

Mar 17, 2008 5:19 AM in response to doug pennington

Yeah, I see the file I attempted to fetch, too -- but there's nothing in it. tftp isn't cleaning up after itself on a timeout; that's a minor issue. The time-out is real...

Message was edited by: Karl Zimmerman

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Answer 10

Mar 17, 2008 8:54 AM in response to Karl Zimmerman

Odd. My text file does have the text content I typed into it to test with. The server is running Panther and I am fetching from a Tiger machine, fwiw.

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Answer 11

Mar 17, 2008 9:34 AM in response to doug pennington

And the mystery continues. You have to understand that I have 4 laptops so I went to a Panther one to fetch from Panther server(remember the other fetches were from Panther to Tiger). And no time out with a get from Panther to Panther and text is intact in fetched file.
Last login: Mon Mar 17 07:56:54 on ttyp3
let us begin
You have mail.
doug-pennington-s-Computer:~ pennington$ tftp 10.0.0.13 69
tftp> get bs.txt
Received 28 bytes in 0.0 seconds
tftp> quit
doug-pennington-s-Computer:~ pennington$

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Answer 12

Karl Zimmerman Author

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2,070 points

Mar 17, 2008 9:44 AM in response to Karl Zimmerman

A skosh more info: tcpdump shows that the server is not sending anything back to the client. At all.

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Answer 13

Mar 17, 2008 10:25 AM in response to Karl Zimmerman

Obviously my dump is showing 7 packets capt, 7 rec by filt, 0 pkts dropped by kernel. But we knew it was working. Just a cross check. On system pref pane, I did new, with port 69, tftp with check on. Now when I did this last night and this am(it wouldn't stay after sleep) I originally typed on the new(under firewall) tftpd because without the d it wouldn't let me ok it. So I did with d, ok'd it, and it now, and last night shows 2 entries of port 69(one w/tftpd & one w/tftp). I don't know why it took that way, but it does and works. And my xinetd is like your directions. My bs.txt in /private/tftpboot are 400(rrr) owned by me, and /private/tftpboot is root w/rwxr-xr-x. And(forget the structure of disable = no, for it still works and isn't worth the change).

service tftp
{
cps = 200 5
disable = no
socket_type = dgram
wait = yes
user = nobody
server = /usr/libexec/tftpd
server_args = /private/tftpboot
groups = yes
flags = REUSE
}

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Answer 14

Karl Zimmerman Author

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2,070 points

Mar 17, 2008 11:07 AM in response to doug pennington

Doug! Thanks for posting your /etc/xinetd.d/tftp file!
Mine had 'server_args = -s /private/tftpboot'. After revising it to match yours, and SIGHUPping xinetd, it worked!

-- Karl

NB : '-s /private/tftpboot' was the original value -- I didn't change it to that!

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Answer 15

Mar 17, 2008 11:38 AM in response to Karl Zimmerman

Karl, You're welcome & glad it works now...Doug

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