Solved (kinda): Peculiar issue with Bridge Adapter Mode

[MariusMatutiae]

deb.zip

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I am trying to configure a Debian Stretch guest on Virtualbox 5.1.8 in a Kubuntu 16.04 host, and I am having several problems.

The compilation of http://download.virtualbox.org/virtualb ... _amd64.deb proceeds
correctly, and there are no errors reported, nor inside /var/log/vbox-install.log. The following modules appear loaded,

Code: Select all

# lsmod | grep -i vb
vboxpci                24576  0
vboxnetadp             28672  0
vboxnetflt             28672  1
vboxdrv               454656  4 vboxnetadp,vboxnetflt,vboxpci

and I could find no errors relating to VB within /var/log.

And yet, network connections work properly only if I choose NAT, or Bridge Adapter with the paravirtualized interface. When I choose
Bridge Adapter with any of the other Adapter Types, connections fail in a peculiar way: from within the guest, I can easily ping and
resolve IP addresses, but standard TCP connections (I did not try UDP) suddenly stop after exchanging a few packets. Loading any Web
page stops immediately, and even LAN connections have problems: I can ssh into a local host, and I can do all sorts of things provided
input and output are short, but, if I just do so much as a ls, the connection freezes. Simultaneous analysis of the packet
flow with tcpdump shows that, after an initial flurry, very few packets are exchanged.



The log file is here,
http://paste.ubuntu.com/23392132/

or here,

deb.zip

(23.84 KiB) Downloaded 10 times

[socratis]

Please attach the file locally. The Ubuntu pastebin requires registration. No gonna happen.

[MariusMatutiae]

Done, thanks for the tip.

[MariusMatutiae]

I circumvented this problem by rolling back Virtualbox to the Kubuntu 16.04 repo version, 5.0.18.

In this case, the very same two VMs (same OVA) worked out of the box. I still do not know why the newer
version of VB, 5.1.8, does not run properly under Kubuntu 16.04 (with a lot of customization,
admittedly). Even an strace analysis did not reveal anything suspicious.

At any rate, thank you all guys for your generous support. But hey, All's well that ends well.