FTP or NTPv3 are examples for application protocols that embed network-layer addresses

[Ori Berger]

Ron Varburg wrote:

> I saw in the wikipedia, don't remember the exact entry, that 
> 
> in contrast to most transport- and application-layer protocols, FTP or NTPv3
>  are examples for application protocols that embed network-layer addresses
> 
> Can someone elaborate on that ? 

FTP in active mode, requires whoever does the get to give his 
address/port (PORT command), using six 8 bit numbers; similarly in 
passive mode, the server gives another address for the client to use -- 
possibly on another server. These were ipv4 addresses; I'm sure there's 
an ipv6 extension as well.

An NTP server gives the ipv4 network addresses of the servers it syncs 
from (if it's using it's own source).

In contrast, HTTP only uses names -- e.g., redirect will be to 
"Location: http://blahblah" with no network-layer addresses. Similarly, 
SMTP only uses host names, not network layer addresses.

Ori