In modern Debian systems, the interface name of a NIC is determined by a rule file that is read by the udev device manager. The rule file is /etc/udev/rules.d/70-persistent-net.rules. Each entry in the file uses a MAC address to determine the name of the corresponding NIC interface.
If you want to rename the interface of a NIC, you can edit that file. However, you must be careful so that the same interface name does not correspond to more than on NICs that can be installed at the same time.
After changing the rules file, you need to make the system aware of the changes. On a command line, you can run /etc/init.d/udev reload for the changes of the rules to become effective. This step, however, does not automatically change the names of interface that are already in the system.
The easier way to rename the NIC interfaces is to reboot the system. If that is impossible or impractical, you can also try the following.
First, locate the driver (module) of the NIC that you want to rename. Let’s say the current interface name of the NIC is eth0. You can look up its module by reading the content of /sys/class/net/eth0/device/uevent. The line starting with DRIVER= indicates the name of the driver.
Once you locate the driver, unload it. Run rmmod r8169 to unload the r8169 driver. Then, reload the driver using modprobe r8169. If you read the last entries of dmesg, you should confirm that the NIC is now using the new interface name.