[syslinux] hpa-tftp source port selection

[H. Peter Anvin]

Darren Gamble wrote:
> Good day,
> 
> I'd just like a bit of information about the source ports that hpa-tftp uses
> for its TFTP file transfers.
> 
> We're using it to transfer files across a network that we have heavily
> firewalled.  So, we'd like to know which ports the TFTP server might use as
> the source port for its data transfers and/or any ways to configure a range
> that it can use.
> 
> I dug through the man page, but wasn't able to find any information.
> 

tftp-hpa, like any other tftp server, uses dynamically assigned ports.
These are constrained only by the setup for dynamic port numbers on the
TFTP host (in Linux, /proc/sys/net/ipv4/ip_local_port_range).

In other words, you can't really get what you asked for.  "TFTP" and
"security" are antonymous; enabling TFTP to cross security domains is an
 oxymoron.

	-hpa