number of ftp connections

[Darren Murray_1]

Hi,

I am in the process of building a ftp server.

There is about 500 users that are going to ftp to this machine.

Is there a setting/kernel parameter that sets the amount of ftp connections possible at a certain time?
Cheers
Darren

P.s Go the Aussies in the World Cup

[Chris Wong]

There is an option in the ftpaccess file called limit.

The limit option grants the administrator the ability to limit the number of FTP sessions. When the class option is used, the limit can be assigned per class. In this example we are limiting the production class to 2 concurrent FTP sessions. The ???Any??? refers to ???Any week day???. Limits can be set for various days and times. For example, Fr0900-1700, can be used for Friday between 9:00AM and 5:00PM. A value of ???1 indicates unlimited sessions. That value can be used to allow unlimited FTP access during certain hours and a 0 value could be used with another limit entry for hours when FTP access is not wanted.
FTP articles can be found here:
http://newfdawg.com/SHP-Articles.htm

- Chris

[Michael Tully]

About the only limit I can see would be from the 'nproc' process limit table. You could limit the number by class if you wished to.
Have a look at the man page for 'ftpaccess'.
Make sure that if you intend doing this that you don't use anonymous 'ftp'

[Steven E. Protter · Accepted solution]

A small recommendation.

Make sure you have adequate space in /var

The logging on that many connections can be volumous.

To keep track of security, you'll want to make sure the -l parameter is in /etc/inetd.conf which will increase logging volume.

inetd -c will reload the config.

To insure there are no permissions and security issues going to bite you, I'd say run Bastille Security Hardening on the box, security_patch_check and the saint utility to probe vulnerabilties.

Links to the free stuff below.

Bastille...

https://payment.ecommerce.hp.com/cgi-bin/swdepot_parser.cgi/cgi/try.pl?productNumber=B6849AA&date=

Required perl support.

https://payment.ecommerce.hp.com/cgi-bin/swdepot_parser.cgi/cgi/try.pl?productNumber=PERL&date=


security_patch_check

https://payment.ecommerce.hp.com/cgi-bin/swdepot_parser.cgi/cgi/try.pl?productNumber=B6834AA&date=

http://hpux.cs.utah.edu/
For saint utility. Get the tar version, compile it yourself.

SEP

[rick jones]

Each FTP session is a separate process, so nproc can come into play.

Each will consume some quantity of RAM. It will also deisre some (larger) quantity of swap space.

Each FTP session will consume a number of file descriptors, so nfile can come into play. The number is on the order of 10, so maxfiles and maxfiles_lim does _not_ come into play.

Apart from that there isn't much else to tweak for kernel settings, but you might look at some of the "FTP" or "download server" papers at ftp://ftp.cup.hp.com/dist/networking/briefs/

to find some of the (now likely a bit out of date) constants.

Oh, and go Sweden :)