I am new to CentOS (coming from Fedora) and I really like it!
I am having difficulty getting one of my machines to boot and assign the same designation of eth0 and eth1 to the same nics consistantly.
I have an MSI motherboard with 2 nics on the board. Strangely enough both nics report the same MAC address. This is not an issue since I use the computer to route between two different subnets so they don't see each other on the network.
The problem comes when I reboot and they race against each other to see which one will get to be eth0. If they switch my routing dies and I loose access with out rebooting and hoping they switch back or switching the actual cables.
I have googled and searched my networking resources but all of the fixes that I have found focus on using the MAC address to solve the problem but in my case they are the same.
The only difference is that they use different drivers. One is a Realtek and other is a Marvell.
I have turned off Kudzu or they reconfigured every time a booted the machine. It only happens every once in a while but I need it to be consistent.
Any suggestions or pushes in the right direction would be most appreciated.
Doug Coats
Doug Coats spake the following on 8/13/2007 11:38 AM:
I am new to CentOS (coming from Fedora) and I really like it!
I am having difficulty getting one of my machines to boot and assign the same designation of eth0 and eth1 to the same nics consistantly.
I have an MSI motherboard with 2 nics on the board. Strangely enough both nics report the same MAC address. This is not an issue since I use the computer to route between two different subnets so they don't see each other on the network.
The problem comes when I reboot and they race against each other to see which one will get to be eth0. If they switch my routing dies and I loose access with out rebooting and hoping they switch back or switching the actual cables.
I have googled and searched my networking resources but all of the fixes that I have found focus on using the MAC address to solve the problem but in my case they are the same.
The only difference is that they use different drivers. One is a Realtek and other is a Marvell.
I have turned off Kudzu or they reconfigured every time a booted the machine. It only happens every once in a while but I need it to be consistent.
Any suggestions or pushes in the right direction would be most appreciated.
Doug Coats
Is the boards bios up to date? Do you have the proper alias entries in /etc/modprobe.conf?
Doug Coats spake the following on 8/13/2007 12:22 PM:
Is the boards bios up to date?
Yes
Do you have the proper alias entries in /etc/modprobe.conf?
These are the relevent listings in the modprobe.conf
alias eth0 r8169 alias eth1 forcedeth
I have seen this issue with other boards that use the forcedeth driver. I think there is some bug in how it interacts with the nic chipset, but haven't seen a current patch. There is a patch slated for 2.6.19 kernel, (http://lwn.net/Articles/199045/) and I am sure RedHat will backport this as soon as it is tested.
On 8/13/07, Doug Coats dcoatshca@gmail.com wrote:
I am new to CentOS (coming from Fedora) and I really like it!
I am having difficulty getting one of my machines to boot and assign the same designation of eth0 and eth1 to the same nics consistantly.
I have an MSI motherboard with 2 nics on the board. Strangely enough both nics report the same MAC address. This is not an issue since I use the computer to route between two different subnets so they don't see each other on the network.
The problem comes when I reboot and they race against each other to see which one will get to be eth0. If they switch my routing dies and I loose access with out rebooting and hoping they switch back or switching the actual cables.
I have googled and searched my networking resources but all of the fixes that I have found focus on using the MAC address to solve the problem but in my case they are the same.
The only difference is that they use different drivers. One is a Realtek and other is a Marvell.
I have turned off Kudzu or they reconfigured every time a booted the machine. It only happens every once in a while but I need it to be consistent.
Any suggestions or pushes in the right direction would be most appreciated.
Doug Coats
As far as I understand networking, if you only have 1 MAC, you only have 1 NIC. You might have 2 connectors, but that seems really strange. It seems like this is some sort of undefined behavior. I think that having only 1 MAC really *IS* an issue.
Is it possible they are set up to do of link teaming or something like that?
My suggestion is to get another network card.
As far as I understand networking, if you only have 1 MAC, you only have 1 NIC. You might have 2 connectors, but that seems really strange. It seems like this is some sort of undefined behavior. I think that having only 1 MAC really *IS* an issue.
I have used these boards(I have 6 of the same motherboard) for about 3 years now with no problems, until I upgraded the OS this summer from Fedora Core 4 to CentOS 5. With every windows install and Linux install on these mother boards they report two separate nics that can both be configured and active at the same time with the same MAC address.
Doug
Doug Coats wrote:
As far as I understand networking, if you only have 1 MAC, you only have 1 NIC. You might have 2 connectors, but that seems really strange. It seems like this is some sort of undefined behavior. I think that having only 1 MAC really *IS* an issue.
I have used these boards(I have 6 of the same motherboard) for about 3 years now with no problems, until I upgraded the OS this summer from Fedora Core 4 to CentOS 5. With every windows install and Linux install on these mother boards they report two separate nics that can both be configured and active at the same time with the same MAC address.
Doug
How can 2 nics from different companies have the same mac address ....
I don't think that is possible.
each card needs a separate MAC address, at least the way I understand networking.
Johnny Hughes spake the following on 8/13/2007 1:21 PM:
Doug Coats wrote:
As far as I understand networking, if you only have 1 MAC, you only have 1 NIC. You might have 2 connectors, but that seems really strange. It seems like this is some sort of undefined behavior. I think that having only 1 MAC really *IS* an issue.
I have used these boards(I have 6 of the same motherboard) for about 3 years now with no problems, until I upgraded the OS this summer from Fedora Core 4 to CentOS 5. With every windows install and Linux install on these mother boards they report two separate nics that can both be configured and active at the same time with the same MAC address.
Doug
How can 2 nics from different companies have the same mac address ....
I don't think that is possible.
each card needs a separate MAC address, at least the way I understand networking.
Most of these boards that I have seen having this problem are using the Marvell gigabit ethernet chipset. It probably either has buggy firmware, or the bios code that these boards use is initializing the net chips wrong. I'm sure that Marvell also provided this code.
On Monday 13 August 2007 21:38, Doug Coats wrote: <cut>
Any suggestions or pushes in the right direction would be most appreciated.
Could you show us the the contents of /etc/sysconfig/network-scripts/ifcfg-eth0 and /etc/sysconfig/network-scripts/ifcfg-eth1?
Could you show us the the contents of /etc/sysconfig/network-scripts/ifcfg-eth0 and /etc/sysconfig/network-scripts/ifcfg-eth1?
ifcfg-eth0
DEVICE=eth0 BOOTPROTO=none BROADCAST=xx.xx.xx.xx IPADDR=xx.xx.xx.xx NETMASK=xx.xx.xx.xx NETWORK=xx.xx.xx.xx GATEWAY=xx.xx.xx.xx ONBOOT=yes TYPE=Ethernet USERCTL=no PEERDNS=no
ifcfg-eth1
DEVICE=eth1 BROADCAST=xx.xx.xx.xx IPADDR=xx.xx.xx.xx NETMASK=xx.xx.xx.xx NETWORK=xx.xx.xx.xx BOOTPROTO=none ONBOOT=yes TYPE=Ethernet USRCTL=no PEERDNS=no
Both have static IP addresses. One is external to a DSL connection and the other Internal to a DMZ.
Doug Coats wrote:
Could you show us the the contents of /etc/sysconfig/network-scripts/ifcfg-eth0 and /etc/sysconfig/network-scripts/ifcfg-eth1?
ifcfg-eth0
DEVICE=eth0 BOOTPROTO=none BROADCAST=xx.xx.xx.xx IPADDR=xx.xx.xx.xx NETMASK=xx.xx.xx.xx NETWORK=xx.xx.xx.xx GATEWAY=xx.xx.xx.xx ONBOOT=yes TYPE=Ethernet USERCTL=no PEERDNS=no
ifcfg-eth1
DEVICE=eth1 BROADCAST=xx.xx.xx.xx IPADDR=xx.xx.xx.xx NETMASK=xx.xx.xx.xx NETWORK=xx.xx.xx.xx BOOTPROTO=none ONBOOT=yes TYPE=Ethernet USRCTL=no PEERDNS=no
If you look in /etc/sysconfig/hwconf it should list both the mac addresses ..
Then maybe a HWADDR= in each of those scripts might help.
BUT, turning off kudzu might also be enough
On 8/13/07, Doug Coats dcoatshca@gmail.com wrote:
I am having difficulty getting one of my machines to boot and assign the same designation of eth0 and eth1 to the same nics consistantly.
I posted something about this back on April 25, Message-ID: 6bb609560704250801y6efe4ec1gbc513ea4f34d5721@mail.gmail.com
What I said then was:
-------- The problem (as I recall) is that on each reboot the onboard NICs are being discovered in a different order, so the MAC addresses in /etc/sysconfig/hwconf don't match what is recorded in /etc/sysconfig/network-scripts/ifcfg-eth*.
I believe what I had to do (I should have written it down, damn it) was hand-edit /etc/sysconfig/hwconf to completely remove all the references to the NICs (there may be more than one entry for each NIC because of the flip-flopping), edit ifcfg-eth* to remove all references to HWADDR, reboot again to let the cards be rediscovered, and then again hand-edit ifcfg-eth* to insert HWADDR lines that match the device assignments in the regenerated /etc/sysconfig/hwconf.
However, I may have at least the last step of that wrong. --------
No one ever responded as to whether that solution worked for them.
Bart Schaefer wrote:
On 8/13/07, Doug Coats dcoatshca@gmail.com wrote:
I am having difficulty getting one of my machines to boot and assign the same designation of eth0 and eth1 to the same nics consistantly.
I posted something about this back on April 25, Message-ID: 6bb609560704250801y6efe4ec1gbc513ea4f34d5721@mail.gmail.com
What I said then was:
The problem (as I recall) is that on each reboot the onboard NICs are being discovered in a different order, so the MAC addresses in /etc/sysconfig/hwconf don't match what is recorded in /etc/sysconfig/network-scripts/ifcfg-eth*.
I believe what I had to do (I should have written it down, damn it) was hand-edit /etc/sysconfig/hwconf to completely remove all the references to the NICs (there may be more than one entry for each NIC because of the flip-flopping), edit ifcfg-eth* to remove all references to HWADDR, reboot again to let the cards be rediscovered, and then again hand-edit ifcfg-eth* to insert HWADDR lines that match the device assignments in the regenerated /etc/sysconfig/hwconf.
However, I may have at least the last step of that wrong.
No one ever responded as to whether that solution worked for them.
Did you try taking out the HWADDR lines in the ifcfg-eth* scripts completely, and putting alias eth0 xxx alias eth1 yyy in /etc/modules.conf where xxx and yyy are the modules for the respective nics?
That should have worked in older versions, but I'm not sure if it still does.
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Bart Schaefer -
Brian Mathis -
Doug Coats -
Johnny Hughes -
Les Mikesell -
Scott Silva -
Todor Petkov