8. procfs: Gone But Not Forgotten
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## 8. procfs: Gone But Not Forgotten

In Linux®, you may have looked at `/proc/sys/net/ipv4/ip_forward` to determine if IP forwarding was enabled. Under FreeBSD you should use sysctl(8) to view this and other system settings, as procfs(5) has been deprecated in current versions of FreeBSD. (Although `sysctl` is available in Linux® as well.)

In the IP forwarding example, you would use the following to determine if IP forwarding is enabled on your FreeBSD system:

`%` `sysctl net.inet.ip.forwarding` net.inet.ip.forwarding: 0

The `-a` flag is used to list all the system settings:

`%` `sysctl -a` kern.ostype: FreeBSD kern.osrelease: 6.2-RELEASE-p9 kern.osrevision: 199506 kern.version: FreeBSD 6.2-RELEASE-p9 #0: Thu Nov 29 04:07:33 UTC 2007 root@i386-builder.daemonology.net:/usr/obj/usr/src/sys/GENERIC kern.maxvnodes: 17517 kern.maxproc: 1988 kern.maxfiles: 3976 kern.argmax: 262144 kern.securelevel: -1 kern.hostname: server1 kern.hostid: 0 kern.clockrate: { hz = 1000, tick = 1000, profhz = 666, stathz = 133 } kern.posix1version: 200112 ...

### Note:

Some of these `sysctl` values are read-only.

There are occasions where procfs is required, such as running older software, using truss(1) to trace system calls, and Linux® Binary Compatibility. (Although, Linux® Binary Compatibility uses its own procfs, linprocfs(5).) If you need to mount procfs you can add the following to `/etc/fstab`:

proc /proc procfs rw,noauto 0 0

### Note:

`noauto` will prevent `/proc` from being automatically mounted at boot.

And then mount procfs with:

`#` `mount /proc`

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