Re: Temporary failure in name resolution error when I try to ping Debian 12 / DomU running on top of the Devuan 5 host os / Dom0

On Sun, Nov 19, 2023 at 10:54 PM Mario Marietto <marietto2008@gmail.com> wrote:

Hello.
I'm trying to configure Debian 12 / DomU on my (Arm32) Chromebook because I want to use the Internet and I want its IP address to be seen from "outside" of my LAN.
This is the tutorial that I'm following :

https://github.com/mobile-virt/u-boot-chromebook-xe303c12/tree/chromebook/xen#starting-a-domu-guest

Given these config files :

A) on the host os (Devuan 5)

Linux devuan-bunsen 6.1.61-stb-xen-cbe+ #1 SMP PREEMPT Sat Nov 4 13:46:17 EDT 2023 armv7l

root@devuan-bunsen:~# ifconfig

lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
       inet 127.0.0.1 netmask 255.0.0.0
       inet6 ::1 prefixlen 128 scopeid 0x10<host>
       loop txqueuelen 1000 (Local Loopback)
       RX packets 2729 bytes 8279984 (7.8 MiB)
       RX errors 0 dropped 0 overruns 0 frame 0
       TX packets 2729 bytes 8279984 (7.8 MiB)
       TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

mlan0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
       inet 192.168.1.7 netmask 255.255.255.0 broadcast 192.168.1.255
       inet6 fe80::8839:239b:9b37:cf84 prefixlen 64 scopeid 0x20<link>
       RX packets 19694 bytes 2193230 (2.0 MiB)
       RX errors 0 dropped 0 overruns 0 frame 0
       TX packets 18757 bytes 10464406 (9.9 MiB)
       TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

vif4.0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
       inet 192.168.1.7 netmask 255.255.255.255 broadcast 192.168.1.255
       ether fe:ff:ff:ff:ff:ff txqueuelen 1000 (Ethernet)
       RX packets 359 bytes 94924 (92.6 KiB)
       RX errors 0 dropped 0 overruns 0 frame 0
       TX packets 42 bytes 1764 (1.7 KiB)
       TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

nano debian.cfg :

kernel = '/Dati/xen/kernels/zImage-6.1.61-stb-xen-cbe+'
memory = '768'
name = 'Debian-bookworm'
vcpus = '1'
disk = [ '/Dati/xen/debian.img,,xvda,w' ]
vif = [ 'type=vif,mac=00:16:3e:12:34:56,script=vif-route' ]
extra = 'console=hvc0 root=/dev/xvda rw init=/sbin/init xen-fbfront.video=24,1024,768'

nano /etc/xen/scripts/vif-route-local :

#!/bin/bash
#============================================================================
# ${XEN_SCRIPT_DIR}/vif-route
#
# Script for configuring a vif in routed mode.
#
# Usage:
# vif-route (add|remove|online|offline)
#
# Environment vars:
# dev vif interface name (required).
# XENBUS_PATH path to this device's details in the XenStore (required).
#
# Read from the store:
# ip list of IP networks for the vif, space-separated (default given in
# this script).
#============================================================================

dir=$(dirname "$0")
. "${dir}/vif-common.sh"
#netdev=$(mlan0)
main_ip=$(dom0_ip)
case "${command}" in
add|online)
echo $dev
echo $ip
echo $main_ip
ifconfig ${dev} ${main_ip} netmask 255.255.255.255 up
echo 1 >/proc/sys/net/ipv4/conf/${dev}/proxy_arp
echo 1 >/proc/sys/net/ipv4/conf/${dev}/forwarding
echo 1 >/proc/sys/net/ipv4/conf/mlan0/forwarding
echo 1 >/proc/sys/net/ipv4/conf/mlan0/proxy_arp
/usr/sbin/arp -i mlan0 -Ds $main_ip mlan0 pub
ipcmd='add'
cmdprefix=''
;;
remove|offline)
do_without_error ifdown ${dev}
ipcmd='del'
cmdprefix='do_without_error'
;;
esac

case "${type_if}" in
tap)
metric=1
;;
vif)
metric=2
;;
*)
fatal "Unrecognised interface type ${type_if}"
;;
esac

# If we've been given a list of IP addresses, then add routes from dom0 to
# the guest using those addresses.
for addr in ${ip} ; do
${cmdprefix} ip route ${ipcmd} ${addr} dev ${dev} src ${main_ip} metric ${metric}
done

handle_iptable

call_hooks vif post

log debug "Successful vif-route ${command} for ${dev}."
if [ "${command}" = "online" ]
then
success
fi

B) on the guest os (Debian 12)

/etc/network/interfaces :

source /etc/network/interfaces.d/*
iface enX0 inet static
address 192.168.1.10/24
gateway 192.168.1.7

/etc/resolv.conf :

options edns0 trust-ad
search homenet.telecomitalia.it
nameserver 8.8.8.8

this is what happens within the guest os (Debian 12) :

root@bookworm:~# ifup enX0

root@bookworm:~# ip a

1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
   link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
   inet 127.0.0.1/8 scope host lo
      valid_lft forever preferred_lft forever
   inet6 ::1/128 scope host noprefixroute
      valid_lft forever preferred_lft forever

2: sit0@NONE: <NOARP> mtu 1480 qdisc noop state DOWN group default qlen 1000
   link/sit 0.0.0.0 brd 0.0.0.0

3: enX0: <BROADCAST,MULTICAST,DYNAMIC,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default
qlen 1000
   link/ether 00:16:3e:12:34:56 brd ff:ff:ff:ff:ff:ff
   inet 192.168.1.10/24 brd 192.168.1.255 scope global enX0
      valid_lft forever preferred_lft forever
   inet6 fe80::216:3eff:fe12:3456/64 scope link
      valid_lft forever preferred_lft forever

root@bookworm:~# ping google.it
ping: google.it: Temporary failure in name resolution

Where can be the error ? thanks.

--
Mario.