Ticket #10525 (new defect)

Opened 2 years ago

Last modified 23 months ago

NAT doesn't report all socket errors to guest via ICMP

Reported by: reidpr Owned by:
Priority: major Component: network/NAT
Version: VirtualBox 4.1.12 Keywords: ICMP
Cc: Guest type: Linux
Host type: Mac OS X


Steps to reproduce (see also notes below):

  1. Install a Debian Wheezy 64-bit guest on a Mac OS 10.7 host.
  2. Configure a NAT network interface.
  3. Install links in the guest.
  4. Locate a server which gives a "destination unreachable" error when pinged from the host.
  5. Inside the guest, try to use links to access that server: "links".

Expected behavior:

  • links immediately displays a "connection refused" error (i.e., the same as what the host does)

Actual behavior:

  • links waits until the connection times out and then displays a timeout error
  • netstat shows the connection in SYN-SENT state until timeout


  • Packets to the host in question can be rejected inside the guest, e.g. "route add -host x.y.z.w reject".


Thanks for your hard work on VirtualBox!

Change History

comment:1 Changed 23 months ago by JonC

I am also seeing this behaviour. ICMP "destination unreachable" packets are dropped between the host and the guest. I have observed it for NAT and host only networks.

In my opinion this is not a problem with the guest network configuration / packet filtering. My host and guest networks are configured in an almost identical manner, the guest shows this problem but the host does not.

  • Version: 4.1.16 r78094
  • Host type: Linux (RHEL 6.2)
  • Guest type: Linux (RHEL 6.2)

I have also observed this behaviour in the below configuration (where clearly the host and guest networks cannot be configured too similarly).

  • Version: 4.1.8 r75467
  • Host type: Windows 7
  • Guest type: Linux (Fedora 16)

comment:2 Changed 23 months ago by Hachiman

  • Summary changed from ICMP packets aren't being copied from host to guest under NAT to NAT doesn't report all socket errors to guest via ICMP
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