If a ping is can find its way form a host on one side to a host on the other side and back, routing must be fine

Yes, ping is a two direction test. It is becoming a very poor test too. Many devices and OS's tend to block it by default.

Chain INPUT (policy DROP 513 packets, 52341 bytes)
pkts bytes target prot opt in out source destination
0 0 ACCEPT tcp -- eth0 * 0.0.0.0/0 0.0.0.0/0 tcp dpt:25565
0 0 ACCEPT udp -- eth0 * 0.0.0.0/0 0.0.0.0/0 udp dpt:25565
0 0 ACCEPT tcp -- eth0 * 0.0.0.0/0 0.0.0.0/0 tcp dpt:139
0 0 ACCEPT udp -- eth0 * 0.0.0.0/0 0.0.0.0/0 udp dpt:139
0 0 ACCEPT 0 -- eth0 * 192.168.1.0/24 192.168.0.0/24
2347 703K ACCEPT 0 -- lo * 0.0.0.0/0 0.0.0.0/0
833 104K ACCEPT 0 -- mueb * 192.168.0.0/24 0.0.0.0/0
0 0 drop-and-log-it 0 -- eth0 * 192.168.0.0/24 0.0.0.0/0
1438 1120K ACCEPT 0 -- eth0 * 0.0.0.0/0 192.168.1.2
0 0 ACCEPT 0 -- eth0 * 0.0.0.0/0 192.168.1.2 state RELATED,ESTABLISHED

Chain FORWARD (policy DROP 0 packets, 0 bytes)
pkts bytes target prot opt in out source destination
833K 229M ACCEPT 0 -- eth0 mueb 0.0.0.0/0 0.0.0.0/0
0 0 ACCEPT udp -- * * 0.0.0.0/0 0.0.0.0/0 udp dpt:5199
0 0 ACCEPT udp -- * * 0.0.0.0/0 0.0.0.0/0 udp spt:5198
0 0 ACCEPT udp -- eth0 mueb 0.0.0.0/0 0.0.0.0/0 udp dpt:25565
0 0 ACCEPT tcp -- eth0 mueb 0.0.0.0/0 0.0.0.0/0 tcp dpt:25565
0 0 ACCEPT 0 -- eth0 mueb 0.0.0.0/0 0.0.0.0/0 state RELATED,ESTABLISHED
762K 275M ACCEPT 0 -- mueb eth0 0.0.0.0/0 0.0.0.0/0
9438 2330K ACCEPT 0 -- mueb mueb 0.0.0.0/0 0.0.0.0/0
0 0 drop-and-log-it 0 -- * * 0.0.0.0/0 0.0.0.0/0

Chain OUTPUT (policy DROP 0 packets, 0 bytes)
pkts bytes target prot opt in out source destination
0 0 ACCEPT 0 -- * eth0 192.168.0.0/24 192.168.1.0/24
0 0 ACCEPT tcp -- * eth0 0.0.0.0/0 0.0.0.0/0 tcp dpt:25565
0 0 ACCEPT udp -- * eth0 0.0.0.0/0 0.0.0.0/0 udp dpt:25565
0 0 ACCEPT tcp -- * eth0 0.0.0.0/0 0.0.0.0/0 tcp dpt:139
0 0 ACCEPT udp -- * eth0 0.0.0.0/0 0.0.0.0/0 udp dpt:139
2427 710K ACCEPT 0 -- * lo 0.0.0.0/0 0.0.0.0/0
0 0 ACCEPT 0 -- * mueb 192.168.1.2 192.168.0.0/24
162 94368 ACCEPT 0 -- * mueb 192.168.0.0/24 192.168.0.0/24
0 0 drop-and-log-it 0 -- * eth0 0.0.0.0/0 192.168.0.0/24
1533 191K ACCEPT 0 -- * eth0 192.168.1.2 0.0.0.0/0
0 0 drop-and-log-it 0 -- * * 0.0.0.0/0 0.0.0.0/0

Chain drop-and-log-it (4 references)
pkts bytes target prot opt in out source destination
0 0 LOG 0 -- * * 0.0.0.0/0 0.0.0.0/0 LOG flags 0 level 6
0 0 REJECT 0 -- * * 0.0.0.0/0 0.0.0.0/0 reject-with icmp-port-unreachable


Not sure if I follow that. I see "ACCEPT 0 -- * mueb 192.168.1.2 192.168.0.0/24" but 1.2 is on eth0?

I clear all the ip rules and get "Operation not permitted".

I also added : /sbin/iptables -I FORWARD -s 192.168.1.0 -d 192.168.0.0 -i eth0 -o mueb -j ACCEPT


but it didn't help.

fixed it!

I used wireshark to trace what was happing on eth0 and found a problem with the router on the 1.0 network.

Thanks all for your help!

Possible cause the policies remaind beeing set to DROP. (Just writing that in case someone uses this thread for reference to a similar problem)

Good to hear that you figured it out. Please mark the thread as solved.