NIC interfaces and physical ports
I have a physical server with 4 network ports and 3 network cables attached to port1 , port2 and port3. OS is Centos 6 and it has 4 files eth0, eth1, eth2 and eth3. Are these files matched with physical ports? I mean if I want to bond port1 and port3 should I config eth0 and eth2? What happens if I create a file named for example eth12 and config my network in eth12?
linux centos networking
asked Oct 10 '18 at 10:49
BlackCrystalBlackCrystal
32811
add a comment |
I have a physical server with 4 network ports and 3 network cables attached to port1 , port2 and port3. OS is Centos 6 and it has 4 files eth0, eth1, eth2 and eth3. Are these files matched with physical ports? I mean if I want to bond port1 and port3 should I config eth0 and eth2? What happens if I create a file named for example eth12 and config my network in eth12?
linux centos networking
asked Oct 10 '18 at 10:49
BlackCrystalBlackCrystal
32811
Can you paste here content of configuration files?
– mrc02_kr
Oct 10 '18 at 11:44
what would be the content of (at least one of the files)? It's also dependant on what service is managing the network. My guess would be that the physical interface is specified in a parameter in the file.
– rudib
Oct 10 '18 at 11:45
@BlackCrystal Please edit the post and paste the content of file there
– mrc02_kr
Oct 10 '18 at 12:00
add a comment |
I have a physical server with 4 network ports and 3 network cables attached to port1 , port2 and port3. OS is Centos 6 and it has 4 files eth0, eth1, eth2 and eth3. Are these files matched with physical ports? I mean if I want to bond port1 and port3 should I config eth0 and eth2? What happens if I create a file named for example eth12 and config my network in eth12?
linux centos networking
asked Oct 10 '18 at 10:49
BlackCrystalBlackCrystal
32811
I have a physical server with 4 network ports and 3 network cables attached to port1 , port2 and port3. OS is Centos 6 and it has 4 files eth0, eth1, eth2 and eth3. Are these files matched with physical ports? I mean if I want to bond port1 and port3 should I config eth0 and eth2? What happens if I create a file named for example eth12 and config my network in eth12?
linux centos networking
linux centos networking
asked Oct 10 '18 at 10:49
BlackCrystalBlackCrystal
32811
asked Oct 10 '18 at 10:49
BlackCrystalBlackCrystal
32811
edited 4 mins ago
BlackCrystal
asked Oct 10 '18 at 10:49
BlackCrystalBlackCrystal
32811
asked Oct 10 '18 at 10:49
BlackCrystalBlackCrystal
32811
asked Oct 10 '18 at 10:49
BlackCrystalBlackCrystal
32811
32811
Can you paste here content of configuration files?
– mrc02_kr
Oct 10 '18 at 11:44
what would be the content of (at least one of the files)? It's also dependant on what service is managing the network. My guess would be that the physical interface is specified in a parameter in the file.
– rudib
Oct 10 '18 at 11:45
@BlackCrystal Please edit the post and paste the content of file there
– mrc02_kr
Oct 10 '18 at 12:00
add a comment |
Can you paste here content of configuration files?
– mrc02_kr
Oct 10 '18 at 11:44
what would be the content of (at least one of the files)? It's also dependant on what service is managing the network. My guess would be that the physical interface is specified in a parameter in the file.
– rudib
Oct 10 '18 at 11:45
@BlackCrystal Please edit the post and paste the content of file there
– mrc02_kr
Oct 10 '18 at 12:00
Can you paste here content of configuration files?
– mrc02_kr
Oct 10 '18 at 11:44
Can you paste here content of configuration files?
– mrc02_kr
Oct 10 '18 at 11:44
what would be the content of (at least one of the files)? It's also dependant on what service is managing the network. My guess would be that the physical interface is specified in a parameter in the file.
– rudib
Oct 10 '18 at 11:45
what would be the content of (at least one of the files)? It's also dependant on what service is managing the network. My guess would be that the physical interface is specified in a parameter in the file.
– rudib
Oct 10 '18 at 11:45
@BlackCrystal Please edit the post and paste the content of file there
– mrc02_kr
Oct 10 '18 at 12:00
@BlackCrystal Please edit the post and paste the content of file there
– mrc02_kr
Oct 10 '18 at 12:00
add a comment |
1 Answer
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This is a long-standing problem, and in RHEL 7, Predictable Network Interface Names were introduced to solve it.
But for RHEL 6.x, unfortunately you'll have to verify which ethN number corresponds to which physical port on your own. If all your NICs use the same driver module, the ordering on a fresh installation is fairly deterministic: depending on the driver module, it will typically be by the NIC's PCI device order, or by MAC address order.
If you have two different NIC drivers, it will depend on which driver was initially loaded first.
When a new NIC is seen for the first time, its MAC address will be recorded in the respective /etc/sysconfig/network-scripts/ifcfg-eth* file with the HWADDR= keyword, and in the /etc/udev/rules.d/70-persistent-net.rules file, and from that point on, if the drivers are loaded in a different order, the system will reassign the eth* names to keep the physical NIC on the same eth* name until the administrator changes it.
Note that there are two locations with the eth*-MAC relationship: if you change just one of them, strange things may happen.
If you're physically at the system, you can use ethtool -p ethN to help you identify each NIC: the command will make the specified NIC blink its LEDs in some distinctive way, if at all possible for that NIC model.
Dual- and quad-port NICs usually have consecutive MAC addresses for their ports; that can sometimes help in identifying which port is which.
answered Oct 10 '18 at 12:28
telcoMtelcoM
16k12143
add a comment |
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1 Answer
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This is a long-standing problem, and in RHEL 7, Predictable Network Interface Names were introduced to solve it.
But for RHEL 6.x, unfortunately you'll have to verify which ethN number corresponds to which physical port on your own. If all your NICs use the same driver module, the ordering on a fresh installation is fairly deterministic: depending on the driver module, it will typically be by the NIC's PCI device order, or by MAC address order.
If you have two different NIC drivers, it will depend on which driver was initially loaded first.
When a new NIC is seen for the first time, its MAC address will be recorded in the respective /etc/sysconfig/network-scripts/ifcfg-eth* file with the HWADDR= keyword, and in the /etc/udev/rules.d/70-persistent-net.rules file, and from that point on, if the drivers are loaded in a different order, the system will reassign the eth* names to keep the physical NIC on the same eth* name until the administrator changes it.
Note that there are two locations with the eth*-MAC relationship: if you change just one of them, strange things may happen.
If you're physically at the system, you can use ethtool -p ethN to help you identify each NIC: the command will make the specified NIC blink its LEDs in some distinctive way, if at all possible for that NIC model.
Dual- and quad-port NICs usually have consecutive MAC addresses for their ports; that can sometimes help in identifying which port is which.
answered Oct 10 '18 at 12:28
telcoMtelcoM
16k12143
add a comment |
This is a long-standing problem, and in RHEL 7, Predictable Network Interface Names were introduced to solve it.
But for RHEL 6.x, unfortunately you'll have to verify which ethN number corresponds to which physical port on your own. If all your NICs use the same driver module, the ordering on a fresh installation is fairly deterministic: depending on the driver module, it will typically be by the NIC's PCI device order, or by MAC address order.
If you have two different NIC drivers, it will depend on which driver was initially loaded first.
When a new NIC is seen for the first time, its MAC address will be recorded in the respective /etc/sysconfig/network-scripts/ifcfg-eth* file with the HWADDR= keyword, and in the /etc/udev/rules.d/70-persistent-net.rules file, and from that point on, if the drivers are loaded in a different order, the system will reassign the eth* names to keep the physical NIC on the same eth* name until the administrator changes it.
Note that there are two locations with the eth*-MAC relationship: if you change just one of them, strange things may happen.
If you're physically at the system, you can use ethtool -p ethN to help you identify each NIC: the command will make the specified NIC blink its LEDs in some distinctive way, if at all possible for that NIC model.
Dual- and quad-port NICs usually have consecutive MAC addresses for their ports; that can sometimes help in identifying which port is which.
answered Oct 10 '18 at 12:28
telcoMtelcoM
16k12143
add a comment |
This is a long-standing problem, and in RHEL 7, Predictable Network Interface Names were introduced to solve it.
But for RHEL 6.x, unfortunately you'll have to verify which ethN number corresponds to which physical port on your own. If all your NICs use the same driver module, the ordering on a fresh installation is fairly deterministic: depending on the driver module, it will typically be by the NIC's PCI device order, or by MAC address order.
If you have two different NIC drivers, it will depend on which driver was initially loaded first.
When a new NIC is seen for the first time, its MAC address will be recorded in the respective /etc/sysconfig/network-scripts/ifcfg-eth* file with the HWADDR= keyword, and in the /etc/udev/rules.d/70-persistent-net.rules file, and from that point on, if the drivers are loaded in a different order, the system will reassign the eth* names to keep the physical NIC on the same eth* name until the administrator changes it.
Note that there are two locations with the eth*-MAC relationship: if you change just one of them, strange things may happen.
If you're physically at the system, you can use ethtool -p ethN to help you identify each NIC: the command will make the specified NIC blink its LEDs in some distinctive way, if at all possible for that NIC model.
Dual- and quad-port NICs usually have consecutive MAC addresses for their ports; that can sometimes help in identifying which port is which.
answered Oct 10 '18 at 12:28
telcoMtelcoM
16k12143
This is a long-standing problem, and in RHEL 7, Predictable Network Interface Names were introduced to solve it.
But for RHEL 6.x, unfortunately you'll have to verify which ethN number corresponds to which physical port on your own. If all your NICs use the same driver module, the ordering on a fresh installation is fairly deterministic: depending on the driver module, it will typically be by the NIC's PCI device order, or by MAC address order.
If you have two different NIC drivers, it will depend on which driver was initially loaded first.
When a new NIC is seen for the first time, its MAC address will be recorded in the respective /etc/sysconfig/network-scripts/ifcfg-eth* file with the HWADDR= keyword, and in the /etc/udev/rules.d/70-persistent-net.rules file, and from that point on, if the drivers are loaded in a different order, the system will reassign the eth* names to keep the physical NIC on the same eth* name until the administrator changes it.
Note that there are two locations with the eth*-MAC relationship: if you change just one of them, strange things may happen.
If you're physically at the system, you can use ethtool -p ethN to help you identify each NIC: the command will make the specified NIC blink its LEDs in some distinctive way, if at all possible for that NIC model.
Dual- and quad-port NICs usually have consecutive MAC addresses for their ports; that can sometimes help in identifying which port is which.
answered Oct 10 '18 at 12:28
telcoMtelcoM
16k12143
answered Oct 10 '18 at 12:28
telcoMtelcoM
16k12143
answered Oct 10 '18 at 12:28
telcoMtelcoM
16k12143
answered Oct 10 '18 at 12:28
telcoMtelcoM
16k12143
16k12143
add a comment |
add a comment |
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Can you paste here content of configuration files?
– mrc02_kr
Oct 10 '18 at 11:44
what would be the content of (at least one of the files)? It's also dependant on what service is managing the network. My guess would be that the physical interface is specified in a parameter in the file.
– rudib
Oct 10 '18 at 11:45
@BlackCrystal Please edit the post and paste the content of file there
– mrc02_kr
Oct 10 '18 at 12:00