Hi all,

I run Mandrake 9.2 on a laptop and PCMCIA card. I use it at home on a home network and on university network.

I usually only plug the network card and everything works. I get a IP address and never had any problems.

Lately, when I plug on university network, linux is not able to get an IP address but it still works at home. I tried the wizard, and some tips I found on this forum; but nothing to do.

Here is what the ifconfig eth0 command returns:
Lien encap:Ethernet HWaddr 00:04:E2:40:A6:14
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:244759 errors:57448 dropped:0 overruns:11 frame:57448
TX packets:0 errors:3287 dropped:0 overruns:0 carrier:6521
...

I think this is enought to see that there is no IP. I installed vmware 3.x with win98 and winxp and in both, internet is working! while not in linux. (I'm actually posting this in a vmware session.) So I just do not understand why this is not working.

Historically, I saw that when the network is not too busy this was working, but 3 weeks ago a was loosing my connection, and comming back after a while... again and again. Now this is just not working.

I just don't know where to search anymore. If someone has experience this or know something ''geek'' I could try... : ) this would be appreciated.

Thanks.

headsman

Which way are you running Vmware (as a Win host or a linux host)? If as a win host with a linux guest I may be able to help...

My operating system is linux and I use rarely windows in vmware when I have absolutely no choices (like coding a small app for someone).

So if my english is right: my host is linux and Windows is guess inside vmware.

is there any log about DHCP?
maybe your DHCP server is broken and send silly configuration ignored by Linux but accepted by Windoze.

I never tought to look at the syslog. Thuersday afternoon (tomorow) I'll be on the school network again, and will send more details, if I can. Now the only thing I can get from the syslog (this is all I know as possible dhcp log) is the following (snap shot):

Feb 9 18:26:03 localhost dhclient: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 6
Feb 9 18:26:09 localhost dhclient: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 12
Feb 9 18:26:21 localhost dhclient: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 14
Feb 9 18:26:35 localhost dhclient: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 14
Feb 9 18:26:49 localhost dhclient: DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 15
Feb 9 18:27:04 localhost dhclient: No DHCPOFFERS received.
Feb 9 18:27:04 localhost dhclient: Trying recorded lease 192.168.2.14

And this last try is not good, since this IP is from my home network.

On another instance, when I tried manually 'ifup eth0' I got in the syslog:
Feb 9 18:21:46 localhost ifplugd(eth0)[3017]: client: Determining IP information for eth0.../sbin/ifup: line 433: 3098 Terminated $DHCP_CLIENT $DHCP_ARGS

It did not worked.

On another occasion I got something like the previous but:
DHCPDISCOVER on eth0 a couple times
DHCPOFFER from 132.211.1.10
DHCPREQUEST on eth0 2 times
DHCPDISCOVER on eth0 a couple more times
then the fatal No DHCPOFFERS...

I don't know how to give you more details, I'm new at linux since a couple months and networking is not my speciality anyway; and less than a kernel hacker : )

On my home network, it works good: DHCPDISCOVER, DHCPOFFER, DHCPREQUEST, DHCPACK... bound to 192.168.2.253

Thanks for your help; tell me anything I could do to give you more informations and I'll answer back tomorow afternoon.

hehe well if it is any consilation, I'm having the same issue =)

strange... according to that : the server never answer the DHCPREQUEST with a DHCPACK. A broken dhcp server maybe? I'm using slackware on this box, and it has an option flag (-r) I could use to "complie with RFC 1541 (obsolete)"
Take a look at it

Also, are you sure your network card isn't broken at school? Since DHCP use udp protocol, it is to feel bad when a network card start freaking out (or when a worm does too much pollution on network... take a look at it maybe)

well in my case, the Network Card works fine under Windows, or it did until Yesterday =) all the Qindow's boxes (and two other linux boxes) are able to find my DHCP server. else where I've read about DHClient working fine with slightly older versions of the Kernel. Oh well I'm away for the next 4 days Hope someone comes across a better solution than to use an Older Kernel.

Ok, I'm currently posting this from my vmware session (winxp) under linux. The network works great. Under linux, I receive no answer to my DHCPREQUEST.

Same problem. But in the begining of the year, when this was working, the network was less loaded... either my network card address is banned (and I would not know why) or their DHCP server is broken; yet it works in vmware.

But I prefer not accepting such a boring conclusion to this problem. In fact I beleive the network card workes fine since there is no prob under vm(winXP). But I don't know enought about linux and networking and kernel to have any probable solutions.

This is still not working, but once I got data for 1 sec. Is there a way to increase the delay between each try of DHCPOFFER in order to give more time to the network to receive an IP address before sending another request? I think that it might be the problem, even if I know noting about all that... I might be wrong.

Thanks.

with dhcpcd I think you can add the "-t" option to wait a certain time (-t 10 will wait 10 second a believe). I don't know about other dhcp clients.
Be sure to not use a value to high, remember this will stop your booting sequence a lot

There is no problems with linux.

In a Internet class I used a port scanner as the teacher was showing. My network card address has been put in the black list of DHCP offers, so the DHCP server is never sending me IP address. This is why it was still working in my VMWare app, because it emulates an other network card.

The network is being upgraded and now instead of being banned, we are simply kicked for a couple minutes (1 minutes). So everything is working good.

Thanks everybody for your help in this issue!

hehehe nice
well your DHCP is prolly banning your MAC address.... but keep in mind you can spoof it using Linux.
try :
ifconfig eth0 down
ifconfig eth0 hw ether 10:10:10:10:10:10
ifconfig eth0 up

then call back the DHCP

happy for you headsman. I am glad that VMware allowed you to keep posting to this thread!

Yeah, the MAC address, I just forgot the name of it.

wow, if I know that I could do that with Linux just 4 weeks ago!!! I will try that Thursday. This will solve my problem: the new network will be completed in 3 weeks, so meanwhile...

Thanks again! I'm learning everyday!