Debian not reachable via its hostname in LAN
Your Ubuntu system has the Avahi daemon running while this is not the case for your Raspberry Pi. Install Avahi to solve the problem:
# apt-get install avahi-daemon avahi-discover libnss-mdns
Your Ubuntu system has the Avahi daemon running while this is not the case for your Raspberry Pi. Install Avahi to solve the problem:
# apt-get install avahi-daemon avahi-discover libnss-mdns