+ *
+ * On Linux, we attempt to look up the interface index and print the
+ * name of the interface on which the packet arrived or was sent.
+ *
+ * This look up is only likely to work well if done on the same machine
+ * as the one on which the capture was done, as the interface with a
+ * given index on the latter machine is unlikely to have the same
+ * name as the interface with that index on the former machine.
+ *
+ * As DLT_LINUX_SLL2 live captures are supported only on Linux, this
+ * means that if the machine on which we're reading the file isn't
+ * running Linux, it's probably not the machine that captured the file,
+ * so we don't bother trying to do the lookup on non-Linux machines.