using anon in /etc/exports

[Marc Ahrendt]

according to "man exports" using anon will take an unkown user and map it to the UID specified by anon. i am not seeing this happen ...any idea why?

cat /etc/exports
/usr/data -anon=202

when i touch a file from a NFS client as a user unknown to the server, the file is not owned by 202 but the UID of the client user!?!

[Peter Godron]

Marc,
please see:
http://www.unix.org.ua/orelly/networking/puis/ch20_02.htm

Last three paragraphs above 20.2.1.2, which start with "Sun's documentation of anon states"

The /etc/passwd file is NOT read

[Marc Ahrendt]

peter, that link is bad

i also learned from HP that supposedly the anon option only applies to root users on UNIX NFS clients ...and has no impact for non-root users

[Jeff Schussele]

Hi Marc,

I suspect this is because your client is coming from a system (Linux in this case) that uses UIDs. The client system reports the effective local UID on access & just because that UID is not "valid" on the server the files will still be owned by the reported UID of the client system. Just because you typed anonymous as a username does not mean your effective UID will not be reported to the server.
The anon feature is designed for clients (like WinBlows) that do not use UIDs.

My $0.02,
Jeff

[Kevin Wright]

correct, it only applies to root, as root is always 0. If you could create files that would be owned by 202 from client a, there could be another client with a valid username with id 202, which may or may not be want you want from a security perspective.

[Kevin Wright]

correct, it only applies to root. For client side security, ensure the filesystem is only writable by users and groups as required.