add vlan tagging at preseed with early_command

[ML mail <mlnospam@yahoo.com>]

Hi,

My network uses VLAN tagging and as such I need to enable VLAN tagging before the preseed automated install of Debian 8 start. For that purpose I have used the following preseed late_command:


d-i preseed/early_command string \
   modprobe 8021q; \
   vconfig add eth0 20; \
   ip link set eth0 up


Unfortunately it does not work because it looks like netcfg puts all interfaces down just before starting DHCP and they do not come backup, as such DHCP fails and the automated installation aborts. 

In case that can be useful here is the netcfg part of my preseed file:

### Network configuration
d-i netcfg/choose_interface select eth0.20
# Any hostname and domain names assigned from dhcp take precedence over
# values set here. However, setting the values still prevents the questions
# from being shown, even if values come from dhcp.
d-i netcfg/get_hostname string unassigned-hostname
d-i netcfg/get_domain string unassigned-domain
# Disable that annoying WEP key dialog.
d-i netcfg/wireless_wep string

Anyone has an idea how I could make this work?

Cheers
ML