I would say, yes... Considering my default sources.list contains lots of debian ftp/http sites. If I understand your question correctly.

Sample output of my apt/sources.list:
Code:
# Security updates for "stable"
deb http://security.debian.org stable/updates main contrib non-free
deb http://security.debian.org testing/updates main contrib non-free

# Security updates for "unstable" user inserted per SecurityHOWTO
deb http://security.debian.org unstable/updates main contrib non-free

# Stable
deb http://ftp2.de.debian.org/pub/debian stable main contrib non-free
deb http://ftp2.de.debian.org/pub/debian-non-US stable/non-US main contrib non-free

# Sources
deb-src http://ftp2.de.debian.org/pub/debian stable main contrib non-free
deb-src http://ftp2.de.debian.org/pub/debian-non-US stable/non-US main contrib non-free

# Testing
deb http://ftp2.de.debian.org/pub/debian testing main contrib non-free
deb http://ftp2.de.debian.org/pub/debian-non-US testing/non-US main contrib non-free

# Sources
deb-src http://ftp2.de.debian.org/pub/debian testing main contrib non-free
deb-src http://ftp2.de.debian.org/pub/debian-non-US testing/non-US main contrib non-free

# Unstable
deb http://ftp2.de.debian.org/debian unstable main contrib non-free
deb http://ftp2.de.debian.org/debian-non-US unstable/non-US main contrib non-free
From what I know, Knoppix is just a unstable version of Debian, or Debian is a stable version of Knoppix, depending on the point-of-view you take. Taking into account the three levels of Debian; Stable, Testing, Unstable - we just be a "close family"

Hope this helps,
Cuddles