mario
2015-10-07 13:41:15 UTC
Hello, my first post.
I use as a gateway a Debian Jessie pc with dnsmasq providing both DHCP
and DNS.
Normally, it works flawlessly, but there may be one bug. On one of my
pcs (Ubuntu 14.04)
I run a VirtualBox instance with an Arch Linux VM for which I have
chosen a Bridged
Adapter mode. When the host is on Ethernet the VM gets an IP address
from dnsmasq
unfailingly. But when the host in on wifi, and the VM still in bridged
adapter mode, the VM
cannot seem to obtain an IP address.
The funny thing is,I see the DHCP request enter the gateway (via
tcpdump), and in
the file `/var/log/daemon.log` I see the recording of a DHCP offer. But
the packet with the
DHCP offer never leaves the gateway: dnsmasq says it has made an offer,
the offer never
leaves the gateway, never mind reaching the client.
Please notice: dnsmasq works perfectly for all other clients, wired or
wifi. It fails only with the
VM, and then only when the host is on wifi.
In the attached files I provide: 1) the dnsmasq.conf file; 2) tcpdump
capture and daemon.log on the
gateway when the host is connected via ethernet; 3) tcpdump capture and
daemon.log when the
host is connected via wifi. The third file shows that dnsmasq IS reached
by the BOOTP/DHCP request
just like in the ethernet case, but tcpdump does NOT show an outgoing
Reply. Firewall configuration
and sysctl.conf have not changed in the meantime.
I also provide, in the following files called packet_eth and
packet_wlan, the whole BOOTP/DHCP packet,
for the case of a connection via ethernet, and then via wifi. The reason
is that I am not sure the
fault in this behavior lies entirely (or exclusively?) with dnsmasq: it
might lie with Arch Linux dhcpcd
package, or perhaps with VirtualBox.
I would be glad of any feedback, I hope I have provided enough info to
allow diagnosing the problem.
Cheers,
Mario
I use as a gateway a Debian Jessie pc with dnsmasq providing both DHCP
and DNS.
Normally, it works flawlessly, but there may be one bug. On one of my
pcs (Ubuntu 14.04)
I run a VirtualBox instance with an Arch Linux VM for which I have
chosen a Bridged
Adapter mode. When the host is on Ethernet the VM gets an IP address
from dnsmasq
unfailingly. But when the host in on wifi, and the VM still in bridged
adapter mode, the VM
cannot seem to obtain an IP address.
The funny thing is,I see the DHCP request enter the gateway (via
tcpdump), and in
the file `/var/log/daemon.log` I see the recording of a DHCP offer. But
the packet with the
DHCP offer never leaves the gateway: dnsmasq says it has made an offer,
the offer never
leaves the gateway, never mind reaching the client.
Please notice: dnsmasq works perfectly for all other clients, wired or
wifi. It fails only with the
VM, and then only when the host is on wifi.
In the attached files I provide: 1) the dnsmasq.conf file; 2) tcpdump
capture and daemon.log on the
gateway when the host is connected via ethernet; 3) tcpdump capture and
daemon.log when the
host is connected via wifi. The third file shows that dnsmasq IS reached
by the BOOTP/DHCP request
just like in the ethernet case, but tcpdump does NOT show an outgoing
Reply. Firewall configuration
and sysctl.conf have not changed in the meantime.
I also provide, in the following files called packet_eth and
packet_wlan, the whole BOOTP/DHCP packet,
for the case of a connection via ethernet, and then via wifi. The reason
is that I am not sure the
fault in this behavior lies entirely (or exclusively?) with dnsmasq: it
might lie with Arch Linux dhcpcd
package, or perhaps with VirtualBox.
I would be glad of any feedback, I hope I have provided enough info to
allow diagnosing the problem.
Cheers,
Mario