File
The purpose of the /etc/networks file
Also wondering what some files are used for on Linux systems? In this article we have a look at the /etc/networks file.
Summary
Also wondering what particular files do on Linux? One of those files we recently rediscovered during auditing is the /etc/networks file. For some reason it was always there, yet we never change it.
When looking at the man page of networks(5) we learn its purpose (almost instantly):
- It translates between IP ranges and network names
- It is used for tools like netstat and route
- It only works on class A, B, or C networks
- It does not work on subnets
Surprisingly enough a test with subnetting actually showed the right names during our test. Digging through the related system calls (getnetbyaddr(3), getnetbyname(3), getnetent(3)), it did not reveal the reason why it worked.