# FreeBSD host refusing connections from VBox guest



## kidde (Oct 3, 2014)

Hello!


I have a server running FreeBSD 10.0 (_192.168.1.1_), used for among other things hosting a VirtualBox guest running Windows Server 2008 R2 (_192.168.1.11_). These machines both connect to the internet using a router with 1 external IPv4 adress, NATing incoming connections (SSH to FreeBSD and HTTP to Windows). So far so good.

A little while ago the FreeBSD host started refusing connections from the VBox guest. SSH from the virtual machine to the host no longer works. However, bouncing the connections off the NAT (ie connection to the outward facing IPv4 address of the router) works just fine. All other hosts on the internal network are able to SSH to the FreeBSD host just fine. The FreeBSD host is not running either pf(), ipfw() or ipfilter(). The only "firewall" in question in use as far as I know is sshguard, where I've explicitly whitelisted the entire local subnet (192.168.1.0/24)

The problem is not unique to SSH, all connections regardless of service from the VM to the host are refused. Also, the VM has no trouble connecting to any other host.

Now to the details:

The server is connected to the network via igb0, which the VBox also uses as its bridged interface.


```
root@entropy:/usr/home/kidde # ifconfig
igb0: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> metric 0 mtu 1500
	options=403bb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,TSO4,TSO6,VLAN_HWTSO>
	ether 00:xx:xx:xx:fe:60
	inet 192.168.1.1 netmask 0xffffff00 broadcast 192.168.1.255
	nd6 options=29<PERFORMNUD,IFDISABLED,AUTO_LINKLOCAL>
	media: Ethernet autoselect (1000baseT <full-duplex>)
	status: active
*snip*
```

`ipconfig /all` on the Windows VM. Please excuse the Swedish.

```
Ethernet-anslutning Anslutning till lokalt nätverk:

   Anslutningsspecifika DNS-suffix . :
   Beskrivning . . . . . . . . . . . : Intel(R) PRO/1000 MT Desktop Adapter
   Fysisk adress . . . . . . . . . . : xx-xx-xx-xx-92-D1
   DHCP aktiverat. . . . . . . . . . : Nej
   Autokonfiguration aktiverat . . . : Ja
   IPv4-adress . . . . . . . . . . . : 192.168.1.11(Standard)
   Nätmask . . . . . . . . . . . . . : 255.255.255.0
   Standard-gateway. . . . . . . . . : 192.168.1.254
   IAID för DHCPv6 . . . . . . . . . : 235405351

   DNS-servrar . . . . . . . . . . . : 8.8.8.8
                                       8.8.4.4
   NetBIOS över TCP/IP . . . . . . . : Aktiverat
```


```
[kidde@entropy ~]$ VBoxManage showvminfo virtualWindows
Name:            virtualWindows
*snip*
NIC 1:           MAC: XXXXXXXX92D1, Attachment: Bridged Interface 'igb0', Cable connected: on, Trace: off (file: none), Type: 82540EM, Reported speed: 0 Mbps, Boot priority: 0, Promisc Policy: deny, Bandwidth group: none
*snip*
```

The start of these problems does not coincide with any change in settings as far as I am aware. I'm thankful for anything to point me in the right direction.


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