Networking on Red Hat 5.5

[rjb123]

Hi All, I think this is a common issue judging by posts on the internet. However, none of the fixes have worked for my setup. I have an HP DL 350 G6 server. Running ESXi 4. It has an additional quad NIC n375t, which I installed the additional drivers for an is picked up in VMWare. I have installed Red Hat Linux 5.5 onto it, which has installed without issue. I have setup one Virtual switch running off the on-board NIC. This runs the management console & the virtual linux machine.

The machine boots up, no errors reported. I have configured a static IP on eth0, correct default gateway & mask. However, I am unable to get any access to the LAN or Internet from eth0. The MAC address matches that of E1000 card when checking the configuration within the Virtual Machine settings. There is RX TX traffic going across eth0, I can ping the loopback, but still can't get any connection beyond the Virtual Machine.

All the blogs suggest changing the Virtual Machine NIC MAC address to the same as the vmnic0 (the only enable NIC). Having done this when rebooting its give an incorrect MAC address error on eth0 and disables it. This is despite amending the \etc\sysconfig\network-scripts\ifcfg-eth0 file to change the MAC address.

This should be easy, and I'm sure someone will know a quick fix. But I am slowly going mad. This used to be so easy on ESX 3.5! Any help or advice would be greatly appreciated.

[toha]

I can't identify any recommendation by VMware which would say that you should duplicate vmnic0 MAC address for VM NIC, I'd say don't do it.

Check that your virtual switch and virtual machine port group are properly configured,

VLAN ID correct?

Uplinks correctly set?

Correct port group selected in virtual machine properties?

[DSTAVERT]

Networking relies on unique MAC addresses. Duplicating an address will break an otherwise functioning network. I would delete the vNIC in the Redhat Machine restart the VM and re add the vNIC. Make sure that you have a functional physical network and double check your network settings. If DHCP is available on the network the RedHat VM is on use it to see if the VM picks up an address.

[rjb123]

Hi, thanks for the feedback. I have reverted back to the default MAC address. I have also provide screen shots of the settings configure. I think the Vswitch, virtual machine port are correctly set as depicted. I have also reset it to pick up DHCP. It has a valid IP address now. However, when pinging the DHCP host it is unreachable from the linux guest OS. I also administer this through VSphere which is running on the same box that host DHCP so I know it can connect to the VM host. Incidently, looks like there was a simillar post back in Feb but not confirmed resolution:

http://communities.vmware.com/message/1451675

Thanks

[ericreasons]

RJB-

I could not have a more exact match to your problem. Tell me you have since figured it out?

-Eric

[golddiggie]

Couple of things come to mind, and stand out from your screenshots..

Why would you assign 16GB of RAM to a Linux VM?

What does your Network Configuration look like? Do you have the Hostname, Primary DNS and DNS search path's populated with correct info?

How about the Ethernet Device settings?

Have you installed the VMware Tools yet?

Network Administrator

VMware VCP4

Consider awarding points for "helpful" and/or "correct" answers.

[rjb123]

Hi,

Thanks for the response. In reply to Ericreasons - no resolution yet. But I have escalated this to Red Hat support as I tried the install on a standalone machine and had exactly the same issue so this is not related to VMware. This is on going with Red Hat as they have not been able to provide a resolution yet. Although they have suggest I try a different Kernal version.

What I have found strange is that I installed an older version, Fedora 7 on this VM box and it installed fine, the networking is OK and its now running the host I had intended to run on Red Hat 5.5. So I am fairly sure VM is not responsible for the networking problems. But having seen Eric response and a number of others on forums I would think this is something of an issue.

Goldiggie - thanks for your response. The Red Hat install was intended to run a simulation programme that is RAM hungry, although 16gb is probably excessive the machine was highly spec'd for this role. As per the above, I am confident the network configuration was setup correctly as the Fedora install worked. The Red Hat support team also confirmed it looked ok when I provided the sosreport to them. What we couldn't figure out was that the machine received an IP from DHCP (which was running as the gateway aswell) and then couldn't ping this machine. Somehow, it seems like the NIC is dropping packets or filtering, despite the Firewall and SELinux being disabled.

I will notify you all if the kernal change makes any difference.

[ericreasons · Accepted solution]

RJB-

We fixed the problem on our end. If you have the Advanced Platform, and you enter the subscription number, you have the option during setup of "Virtualization" (the same screen as Web, development tools, and Clustering).

There is a problem with Red Hat's Virtualization running while the server is itself virtualized. (I appears that the virtualization configuration is when the server is running as a host, not a guest OS)

I reinstalled without virtualization, and networking works like a charm.

Hope this helps!

[rjb123]

Hi Eric,

Sounds like a viable reason. I am scheduling some downtime on the machine to re-add the quad nic. Once I have done this, I will re-install the RHEL with this option removed and see where I get. But it would make sense this is causing the issue.

I'll let you know if this resolves the issue. You should probably let Red Hat know aswell, they probably have a few open calls on this one.

Thanks again,

[rjb123]

Hi Ericreasons,

That seems to be it, worked for me to. So thank you very much for sharing the information. I advised the open support ticket with Red Hat, that this option shouldn't default to 'ticked' or at least should have some additional information about what the significance is. As both RH & VM support seemed to be in the dark about this.

Thanks again.