Host IP argument to port forward rule not working with aliased host interface

[Scramblejams]

I have a service running on the Debian guest listening on port 8080. I would like to access that service via a port on the host (using the host's IP, 10.0.0.3). If I use the following command to set up the port forward...

VBoxManage modifyvm debianvm --natpf1 "my_fwd,tcp,,8080,,8080"

...it works fine. I can connect to 10.0.0.3:8080 and it works correctly.

However, I have also defined a number of IP aliases on eth0, e.g. eth0:0 is 10.0.0.20. I would like my port forward to _only_ listen on 10.0.0.20. So I delete the old forward and use the following command...

VBoxManage modifyvm debianvm --natpf1 "my_fwd,tcp,10.0.0.20,8080,,8080"

...and it does not work. Nothing's listening on 10.0.0.20.

==================================================================

Host kernel: 3.2.0-4-amd64, guest kernel: 3.2.0-4-486, VirtualBox version: 4.2.14-86644

Output of host's ifconfig -a :

eth0      Link encap:Ethernet  HWaddr <<redacted>>
          inet addr:10.0.0.3  Bcast:10.0.0.255  Mask:255.255.255.0
          inet6 addr: <<redacted>>/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:30239324 errors:6 dropped:29149 overruns:0 frame:6
          TX packets:30811647 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:20244529555 (18.8 GiB)  TX bytes:24759658051 (23.0 GiB)
          Interrupt:20 Memory:e1200000-e1220000

eth0:0    Link encap:Ethernet  HWaddr <<redacted>>
          inet addr:10.0.0.20  Bcast:10.255.255.255  Mask:255.0.0.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          Interrupt:20 Memory:e1200000-e1220000

eth0:1    Link encap:Ethernet  HWaddr <<redacted>>
          inet addr:10.0.0.21  Bcast:10.255.255.255  Mask:255.0.0.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          Interrupt:20 Memory:e1200000-e1220000

eth0:2    Link encap:Ethernet  HWaddr <<redacted>>
          inet addr:10.0.0.22  Bcast:10.255.255.255  Mask:255.0.0.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          Interrupt:20 Memory:e1200000-e1220000

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:852909 errors:0 dropped:0 overruns:0 frame:0
          TX packets:852909 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:1237740824 (1.1 GiB)  TX bytes:1237740824 (1.1 GiB)

Output of host's route -n :

Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         10.0.0.1        0.0.0.0         UG    0      0        0 eth0
10.0.0.0        0.0.0.0         255.255.255.0   U     0      0        0 eth0
10.0.0.0        0.0.0.0         255.0.0.0       U     0      0        0 eth0

Output of guest's ifconfig -a :

eth0      Link encap:Ethernet  HWaddr <<redacted>>
          inet addr:10.0.2.15  Bcast:10.0.2.255  Mask:255.255.255.0
          inet6 addr: <<redacted>>/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:3155 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1761 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:1794350 (1.7 MiB)  TX bytes:189097 (184.6 KiB)

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)

Output of guest's route -n :

Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         10.0.2.2        0.0.0.0         UG    0      0        0 eth0
10.0.2.0        0.0.0.0         255.255.255.0   U     0      0        0 eth0

Relevant lines from VboxManage showvminfo debian using the host-wide port forward:

NIC 1:           MAC: <<redacted>>, Attachment: NAT, Cable connected: on, Trace: off (file: none), Type: 82540EM, Reported speed: 0 Mbps, Boot priority: 0, Promisc Policy: deny, Bandwidth group: none
NIC 1 Settings:  MTU: 0, Socket (send: 64, receive: 64), TCP Window (send:64, receive: 64)
NIC 1 Rule(0):   name = my_fwd, protocol = tcp, host ip = , host port = 8080, guest ip = , guest port = 8080

Relevant lines from VboxManage showvminfo debian using the specific host IP port forward:

NIC 1:           MAC: <<redacted>>, Attachment: NAT, Cable connected: on, Trace: off (file: none), Type: 82540EM, Reported speed: 0 Mbps, Boot priority: 0, Promisc Policy: deny, Bandwidth group: none
NIC 1 Settings:  MTU: 0, Socket (send: 64, receive: 64), TCP Window (send:64, receive: 64)
NIC 1 Rule(0):   name = my_fwd, protocol = tcp, host ip = 10.0.0.20, host port = 8080, guest ip = , guest port = 8080

[Scramblejams]

Neglected to mention that the host is Debian as well.

[Valery Ushakov]

Binding port-forwarding to an alias works for me in 4.3. As a workaround can you try specifying guest's IP in the rule and see if that makes it work?

[Scramblejams]

Hi Vushakov,

Thanks for your note. I've since migrated to Xen, sorry. Since I was on 4.2 and you're on 4.3, if this works for you, then this bug should probably be closed.

[Valery Ushakov]

I've tested that binding port-forwarding rule to an alias on the host also works on 4.2 branch (4.2.26). Closing.