UML and ethertap: what I miss?

I want to run my UML istance with network In the host machine I create the script USER=myname BRIDGENAME=br0 tunctl -t tap0 -u $USER ip link set tap0 up /usr/sbin/brctl addif $BRIDGENAME tap0 ip addr add 10.2.0.5/24 dev tap0 The tap0 is created and no error is reported. After this I launch the uml istance /usr/bin/linux ubda=fsroot mem=1024M con0=fd:0,fd:1 con=pts eth0=ethertap,tap0,10.2.0.5 Then I enter in the uml istance with minicom and I try to configure the network ip addr add 10.2.0.6/24 dev eth0 ip route add default via 10.2.0.5 Error: Nexthop has invalid gateway. What I miss? Why is not comunicating? I have tried also using the classical iptables rules for natting echo 1 > /proc/sys/net/ipv4/ip_forward iptables -A FORWARD -i tap0 -o br0 -j ACCEPT iptables -A FORWARD -i br0 -o tap0 -m state --state NEW,ESTABLISHED,RELATED -j ACCEPT iptables -t nat -A POSTROUTING -o br0 -j MASQUERADE but nothing change.