can't get tcp/ip to work under qemu/SPARC64/NetBSD 6.1.5

[Dennis Luehring <dl.soluz%gmx.net@localhost>]

i try to build a system for while-develop big-endian/unaligned acces 
checks, got a working debian-sparc64
running - buts its awfully slow due to 32/64-kernel/userland mixup - 
NetBSD is pure SPARC64 and is blasting
fast under qemu - the installation runs very quick (just a few minutes) 
from CD/with "full without X"
but i can't get the network to work - trying to use dhcp during 
installation fails, manual IP settings fail also
i don't know if it is a hardware(emulation) problem or my little to none 
knowledge of NetBSD

Qemu:

using git qemu 2.3.93 (latest release 2.2 isn't able to boot NetBSD at all)

needed packages under ubuntu (15.04) for building

g++
git
glib2.0-dev
libfdt-dev
libgtk2.0-dev
libncurses5-dev
libpixman-1-dev
libsdl1.2-dev
libvte-dev
zlib1g-dev

git clone git://git.qemu-project.org/qemu.git
cd qemu
./configure --target-list=sparc64-softmmu
make // no "make install" neeeded

Image:

using the SPARC64 NetBSD 6.1.5 iso image
ftp://iso2.de.netbsd.org/pub/NetBSD/iso/6.1.5/NetBSD-6.1.5-sparc64.iso

base on this small howto:
http://gunkies.org/wiki/Installing_NetBSD_6.1.5_Sparc64_on_Qemu

Create image:
~/qemu/qemu-img create -f raw ~/netbsd/netbsd-615-sparc64.raw 2G

Start installation (use cd0c if asked)
~/qemu/sparc64-softmmu/qemu-system-sparc64 -m 1024 -nographic -monitor 
telnet::4440,server,nowait -serial telnet::3000,server -hda 
./netbsd-615-sparc64.raw -cdrom ./NetBSD-6.1.5-sparc64.iso -boot d -net 
nic -net user

Run installed system (use wd0a if asked)
~/qemu/sparc64-softmmu/qemu-system-sparc64 -m 1024 -nographic -monitor 
telnet::4440,server,nowait -serial telnet::3000,server -hda 
./netbsd-615-sparc64.raw -cdrom ./NetBSD-6.1.5-sparc64.iso -boot c -net 
nic -net user

telnet localhost 3000 - guest
telnet localhost 4440 - qemu monitor