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Legacy Forums => Experienced User Forum => Topic started by: Guoping Zhang on December 27, 2002, 05:58:47 PM

Title: redhat_8 dhcp client won't work, why?
Post by: Guoping Zhang on December 27, 2002, 05:58:47 PM

Dear friends,

I made a few attempts to configure a dhcp client (using dhclient with redhat 8) but never suceeded.
 
A LAN consists of 3 PCs.  PC-A is installed a SME5.5 connected to both ADSL and an ethernet hub using two NIC; PC-B, a window-XP PC as a DHCP client, no any problem and first try succeeded; PC-C, a redhat_8 using dhclient as DHCP client (NIC is SMC EZ 1211TX) ---- failed so far without luck.

tcpdump at PC-A shows that the 'DHCPDiscover' is sent from PC-C and received at PC-A, the 'DHCPOffer' is sent from PC-A but not reveived by PC-C ('/var/log/boot.log' at PC-C indicate the 'DHCPOffere is not received).

This causes the IP address for eth0 cannot be found at bootup.

ping other PC in the LAN from PC-C show 'destination is unreachable'

I have a few questions:
  1.  Did any one have similar problems before? how do you resolve?

  2. Ethernet card is working, I tried either SMC 1211TX (using rtl8139too.o driver)
      or Intel expresspro 10/100 (using eepro100.o driver), the problem are same.
      And both work fine under the Window XP

  3. driver problems?
     I use the rtl8139too.o for SMC 1211 TX (or eepro100.o if Intel express pro is
     used). Both drivers are with redhat 8 release and I didn't recompile

     Any problem there?

  4. redhat 8 uses dhclient (not 'pump' and not 'dhcpcd'), any protocol compatiblity
      problem with the SME5.5's dhcpd?

  5. I checked '/etc/resolv.conf', modules.conf, and /etc/sysconfig/network-scripts/ifcfg-eth0, they are okay according the doc.

  6. I tried to set the PC-C as non DHCP client by explicitly assigning the
      IP and gateway and also not working

Thanks advance. Any comments will be appreciated. Thank you.

Guoping

Title: Re: redhat_8 dhcp client won't work, why?
Post by: Dan G. on December 27, 2002, 06:34:49 PM

The only time I have ever seen dhcp problems the source was always the result of a network switch issue.  My recommendation would be to test the Red Hat client using a crossover cable connected directly to the NIC of the SME server.  If that works, it would appear there is a conflict between the linux driver for the card and the hub/switch you are connecting to.  

You might also make sure the card is forced to specific speed and duplex settings, as "Auto-select" can have unpredictable results in mixed-vendor situations.

Title: Re: redhat_8 dhcp client won't work, why?
Post by: Mike on December 30, 2002, 07:32:48 AM

No problems here in getting RH 8 DHCP client to talk successfully to SME.  Worked without any special tweaks.

Title: Re: redhat_8 dhcp client won't work, why?
Post by: Guoping Zhang on January 04, 2003, 01:14:20 AM

Dan/Mike,

Thanks for the responses.

I found the cause of the problem. I used a ASUSP4S333-VM motherboard, where a onboard sound card is configured a particular way that conflits to the ethernet card.

I disabled the on-board sound-card and the DHCP client worked instantly.

Many thanks for your responses.

Regards,
Guoping