[K12OSN] Lost MACs in routing ....

norbert bear2bar at netscape.net
Fri Apr 2 22:34:51 UTC 2004

Hi & thanks for the response, please read on to your questions for 

ckjohnson at gwi.net wrote:

> norbert wrote:
>> The IP setup is as follows;
>> Cable Modem -> (DHCP)Router (> (a) (Static eth1 
>> server & Gateway(static eth0 
>> ->(DHCP) hub ->( - 253) thin clients & MACs (teaching)
>>                                  -> (b) (DHCP - 200)hub 
>> -> Office MACs
>> The thin clients & the server & the Office MACs all work well but the 
>> Teaching MACs cannot get "out" ??? They do get an IP address & can 
>> ping the server & the workstations but not the router!
> What subnet mask is the dhcp server on LTSP box giving out?  If the 
> MACs were getting 192.168.0.x/ then they would try to reach 
> the router on the local segment instead of routing through the LTSP 
> box.  Depending on how you tested ping for thin clients, it may 
> actually have been a ping from the server.  If you used a text mode 
> console on the thin client and it worked, then the subnet mask is not 
> the issue. 

The router subnet is and the K12ltsp server subnet (defined 
in dhcpd.conf is
The ping was from a terminal console

> What default gateway is the dhcp server on LTSP box giving out?  If 
> the MACs were getting anything other than or were 
> configured to not get gateway via dhcp then they would not know how to 
> reach addresses not on the local subnet.  If pinging was tested using 
> thin clients through the desktop login then an incorrect gateway (or 
> no default gateway) could be the problem.  If tested using a text mode 
> console on the thin client then the gateway offered must be correct, 
> but perhaps the MACs are not getting that setting from dhcp? 

The default GW is
If the MAcs are not getting the gateway info, but they are getting an IP 
address from the K12ltsp server, how do I corrrect that ? I did try to 
enter it manually...

> Is ip forwarding turned on and a nat rule added by starting the nat 
> "service" on the LTSP server?  Again if client pinging was tested from 
> desktop login then no forwarding or nat hiding was necessary, and one 
> of these could be the problem.  If tested from a text mode console 
> then ip forwarding and nat cannot be the problem. 

I don't believe that any IP forwarding is active, iptables is turn off, 
but I'm not sure about NAT (Network Address Translation)..

> I would start by verifying that ip forwarding and a nat rule are set 
> at the LTSP server.  If those are correct then look at the ip settings 
> of one of the teaching MACs and the /etc/dhcpd.conf file to figure out 
> what is wrong. 

The teaching MACs are only getting DHCP service from the server they are 
not "MAC thin clients"
As I've said before the MACs are getting IP addresses and verified on 
the server in the log files and responding to pings from the server & 
the thin clients but NOT from outside ......... !!!!!!!

Any more ideas I do need to get this working !!!! H E L P 
...............  :-[

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://listman.redhat.com/archives/k12osn/attachments/20040402/e6e81e8c/attachment.htm>

More information about the K12OSN mailing list