On 04/26/16 22:12, Thomas Huth wrote:
> On 26.04.2016 21:25, Programmingkid wrote:
>> On Apr 26, 2016, at 3:00 PM, Dr. David Alan Gilbert wrote:
>>> Does ping work?
>> I can ping the virtual router at 10.0.2.2. Any other ip address fails.
>
> That's normal for user-mode / slirp networking. You can't ping external
> hosts with this mode.
Side note: yes, you can.
I do it whenever I want to check network connectivity from within ad-hoc
OVMF guests, using the PING command of the UEFI shell. ("Ad-hoc guest"
implies user-mode / slirp.)
It can be enabled with the following steps:
(1) Determine the main group ID (or one supplementary group ID) of the
user that will run QEMU with slirp.
(2) In /etc/sysctl.conf (or whatever is appropriate for your host
distro), make sure that the whitespace separated inclusive group ID
range in the "net.ipv4.ping_group_range" sysctl includes the above group ID.
For example,
- you could add a new group called "unpriv_ping":
groupadd unpriv_ping
- set this group for a number of users as another supplementary group:
for U in user1 user2 ... usern; do
usermod --append --groups unpriv_ping $U
done
(note, they will have to re-login),
- then set both sides of the inclusive range in the above sysctl to the
numeric ID of the new group:
(
GROUP_ID=$(getent group unpriv_ping | cut -f 3 -d :)
printf 'net.ipv4.ping_group_range = %u %u\n' $GROUP_ID $GROUP_ID \
>> /etc/sysctl.conf
)
sysctl -p
Thanks
Laszlo
