configure ftpd port range

[John DeStefano]

Lowell Gilbert <freebsd-questions-local at be-well.no-ip.com>> wrote:
Thanks for your response, Lowell, as always.
 
John DeStefano writes:
>> Due to ISP restrictions, I must change the default port on which ftpd 
>> runs in order to enable ftp access to and from my machine.
 
> That would violate the FTP spec, and isn't supported (IIRC) by the
> standard FreeBSD ftpd.
 
Obviously, I'm not looking to 'violate' any specs, or to have any RFCs 
changed in order to accomodate my personal server.  I'm just looking for a
viable solution to a problem that I'm sure others have come across.
 
>> I had to do the same for my httpd server, but that information was a
>> bit more accessible.
>> Reading material has been sparse, but I've read that adding a port 
>> number/range to the ftpd entry /etc/services and /etc/inetd.conf might
>> do the trick.
>> Is this an acceptible way of going about changing the ftp ports?
 
> It won't work.
 
Why not?  If you were to specify a new port number both in 'services' and
'inetd.conf', and the proper firewall holes were punched, why would it
fail?
 
>> If this box is sitting behind a hardware firewall (Linksys router), what 
>> range would you recommend I open in the firewall for a maximum of 5
>> ftp users? Same question for security on the FBSD box itself?
 
> This is going to be a royal pain anyway. The FTP protocol is tricky
> to get through firewalls, and *very* tricky to get through NAT.
> If you can use, e.g., scp(1) to move your files around, you'll be in
> much better shape -- FTP passes cleartext passwords. However, if
> you're really stuck on FTP (and I am not encouraging you to violate
> your contract with your ISP, but just giving the advice for
> informational purposes), there are other FTP daemons that can change
> the base ports. You'll need to punch holes for the data ports, though.
 
Strangely enough, it sounds like moving away from the stock ftpd,
and using a 3PP daemon to configure the new ports, is the way to go.
Any suggestions on ports and methods?

>> Quick sidebar: DNS is setting my domainname to my ISP's domain,
>> not my local domain, which is causing some problems. "man 
>> domainname" tells me " The super-user can set the domain name by 
>> supplying an argument", which I assume means "domainname 
>> ". But this setting does not stick on reboot. Is there an 
>> easy fix?
> According to the FreeBSD Handbook, the FreeBSD FAQ, and the rc.conf(5)
> manual, setting "hostname" in /etc/rc.conf is what you're looking for.
 
The handbook merely specifies to use the format:
hostname="foo.example.com"
in rc.conf; it doesn't say what to do when the system automatically 
changes the hostname on you on boot/reboot, presumably due to DHCP 
communications.  I could be mistaken, but I don't see this topic in the 
FAQ (which currently covers up to 4.X) at all.  'man' says: 
"If dhclient(8) is used to set the hostname via DHCP, this variable 
should be set to an empty string."  However, I believe that's what's
happening now and may be the reason why 'hostname' is getting reset
incorrectly; see below:
 
# cat /etc/rc.conf |grep hostname
#hostname="gandalf.istari"
hostname="gandalf"
hostname="gandalf.Optonline.net"
 
My manual entry has been commented out, and new entries made.  How would 
one keep this from getting changed automatically?
 
Thanks,
John



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