In RHEL 6.1 the default names assigned to Dell server network interfaces changed from ethX to emX and pXpX. The new names describe where a network interface physically resides in the system, and will have the following format:
- emX
- the X (first, second, etc.) onboard interface
- pXpY
- PCI device X port Y
Dell wrote a really good white paper on this, and the following text from the document summarizes how the pieces fit together:
"A naming mechanism that can impart meaning to the network > interface‟s name based on the physical location of a network port in > concordance to the intended system design is necessary. To achieve that, > the system firmware has the ability to communicate the intended order > for network devices on the mother board to the Operating System via > standard mechanisms such as SMBIOS and ACPI. > > The new naming scheme uses 'biosdevname' udev helper utility , developed > by Dell and released under GPL, suggests new names based on the location > of the network adapters on the system as suggested by system BIOS."
I like the new format, and this will definitely be a nice addition to hardware provisioning systems. Hopefully in the near future we won't have to poke around with lspci to see which interface is which. :)