This early morning, I analyzed and compared the BII hex dump packets from wireshark and packets captured in host.
I found that the host PC kept on sending ICMP to my router and saying that guest OS IP is not reachable.
I looked into iptables chain rule. It does specify this rule. So I disabled firewall completely
sudo systemctl disable firewalld.service
Now, I can't replicate the issues any more. I'm not sure if I feel happy or not.
But next time if whoever encounters this, please do the followings:
1. Keep using BII from my sheep-net-bug-fix-debug branch
./BasiliskII > /tmp/debug.log
# You should ping/DNS/http in guest OS to generate packet output from log
python extract_eth_hex.py -i /tmp/debug.log -o /tmp/hexdump.log
2. Open wireshark on host PC and capture packet.
Keep /tmp/hexdump.log from 1 and packet from 2. Notify me by opening issues in my macemu git repo.
This is most painful thing if it can't replicate every time.