I have a virtual machine running under VirtualBox with Leap15 and firewalld active. Ethernet card is bridged to the physical ethernet card in VirtualBox.
Trying to diagnose an issue (actually with an IPsec VPN) I wanted to check that ip packets were being forwarded between interfaces as they seem not to be. So I added a second interface (eth1). Both interfaces are now bridged to the same physical ethernet card on the host via VirtualBox. I have the following setup:
eth0: 192.168.25.133 [255.255.255.0] with a default gateway of 192.168.25.1 all set by DHCP from my router.
eth1: 10.0.0.1 [255.0.0.0]
“ip route” gives:
default via 192.168.25.1 dev eth0 proto dhcp 10.0.0.0/8 dev eth1 proto kernel scope link src 10.0.0.1
192.168.25.0/24 dev eth0 proto kernel scope link src 192.168.25.133
On this machine I have full internet access via the router and can access both the 192.168.25.* and 10...* networks. All network machines respond to pings.
On a separate machine (ip: 10.0.0.100 with a default gateway of 10.0.0.1) I can ping 10.0.0.1 (gateway) and 192.168.25.133 (local ip on the VirtualBox machine) but not 192.168.25.1 or anything else on that subnet (192.168.25.*) including the internet (I know I don’t have DNS on this machine so have been pinging ip addresses directly). As such I can see both local addresses on my VirtualBox machine but nothing beyond that. It feels like forwarding is turned off or not working.
Yes I have enabled IP-forwarding in Yast (and ‘sysctl net.ipv4.ip_forward’ gives: ‘net.ipv4.ip_forward = 1’) and have no ipv6 options activated. I get the same result with firewalld active (both interfaces set to ‘trust’) and with the firewalld service stopped. I also have fail2ban active but that makes no difference if I kill that service too. If I turn off forwarding on the VirtualBox machine (i.e. net.ipv4.ip_forward=0) I get exactly the same results including responses from 192.168.25.133.
What the heck am I doing wrong or not doing?
Thanks in advance …….