NFS-root support indirectly broken in Feisty

did you set the right options to create a netboot initramfs in /etc/initramfs-tools/initramfs.conf and updated the initramfs with update-initramfs -u ?

nfs root works fine for plenty ltsp users in feisty and it seems it also worked flawlessly when the netbooting installer images were tested (according to https://www.stgraber.org/ubuntu/isotesting/test/173)

Well I wouldn't rule out user error, but I'm following similar steps to how I setup Dapper & Edgy:

http://developer.novell.com/wiki/index.php/Edgy/HOWTO:_Convert_Ubuntu_to_Diskless

LTSP isn't affected with NFS as Ubuntu is the file server and can cope with TCP NFS. I'm using an Infrant ReadyNas appliance and it currently cannot :(

I don't know what happened with Avahi, this is using the install per default from the alternative CD, I have one server created by debootstrap that works perfectly (albeit #1) because the desktop components are not there. I can see that the avahi-autoipd is new. One thing special might be using DHCP, the address is fixed by MAC address on the DHCP server though. This might be causing the problems. I need to investigate the DBUS side more, the first Avahi problem is easy to resolve:

original:

        CONFLICT|UNBIND|STOP)
            ip addr del "$3"/16 brd 169.254.255.255 label "$2:avahi" scope link dev "$2"
            ip route del default dev "$2" metric 1000 scope link || true
            ;;

fixed:
        CONFLICT|UNBIND|STOP)
            ip addr del "$3"/16 brd 169.254.255.255 label "$2:avahi" scope link dev "$2"
            grep -q -v ip= /proc/cmdline
            if [ $? -eq 0 ]; then
            ip route del default dev "$2" metric 1000 scope link || true
            fi
            ;;

s/ip= /nfsroot= /

My hypothesis with the DBUS issue is the lack of any (static) entry in /etc/network/interfaces causes DHCDBD to call dhclient which drops the IP and requests a new address. LTSP clients are not affected here because DBUS and friends don't run on the terminal.

Ok, the last one is a dupe: Bug #92338 in network-manager (Ubuntu)

The avahi fix mentioned above goes in /etc/avahi/avahi-autoipd.action

I found the "Deactivating device %s" and "Will activate wired connection..." messages in binary /usr/sbin/NetworkManager, so it doesn't look like there's an easy way to get around this other than patching NetworkManager.

Feisty is not supported anymore.