Linux not seeing Solaris

We have a "Sunw,ultra-2;sparc sun4u" server running Solaris 5.5.1, and I'm trying to get our Linux ftp server running Red Hat software to interface with
the Sun Solaris. Our administrator was let go last week and I,m a Mac operator that knows little about
PC or net working. All help would be greatly appreciated.

Check /etc/hosts.allow file to insure the Linux IP (or subnet) is allowed. (Do this on the Solaris system)

What account are you trying to ftp in as? Usually root is not allowed to ftp.

Check that you can ftp from the Linux system to itself and from the Solaris system to itself using the account you were trying before.