alors bizarrement après avoir pris un peu le soleil j’ai fait le test suivant :
changement du câble réseaux et connexion sur un autre port de mon switch.
arret relance du reseaux :
/etc/init.d/networking stop
/etc/init.d/networking start
==> réseaux ok
arret relance du serveur
message au démarrage du poste :
No DHCPOFFERS received.
No working leases in persistent database - sleeping.
le pc démarre donc sans réseau
root@olddeb:~# ifconfig
eth0 Link encap:Ethernet HWaddr 00:80:ad:0a:06:06
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:3 errors:0 dropped:0 overruns:0 frame:0
TX packets:4 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 lg file transmission:1000
RX bytes:576 (576.0 B) TX bytes:0 (0.0 B)
Interruption:18 Adresse de base:0xd400
lo Link encap:Boucle locale
inet adr:127.0.0.1 Masque:255.0.0.0
adr inet6: ::1/128 Scope:Hôte
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:8 errors:0 dropped:0 overruns:0 frame:0
TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 lg file transmission:0
RX bytes:480 (480.0 B) TX bytes:480 (480.0 B)
effectivement je n’ai pas d’ip
je tente donc un arrêt relance du service réseaux
root@olddeb:~# cd /etc/init.d
root@olddeb:/etc/init.d# ./networking stop
[....] Deconfiguring network interfaces...Internet Systems Consortium DHCP Client 4.2.2
Copyright 2004-2011 Internet Systems Consortium.
All rights reserved.
For info, please visit https://www.isc.org/software/dhcp/
Listening on LPF/eth0/00:80:ad:0a:06:06
Sending on LPF/eth0/00:80:ad:0a:06:06
Sending on Socket/fallback
DHCPRELEASE on eth0 to 192.168.0.254 port 67
send_packet: Network is unreachable
send_packet: please consult README file regarding broadcast address.
done.
root@olddeb:/etc/init.d# ./networking start
[....] Configuring network interfaces...Internet Systems Consortium DHCP Client 4.2.2
Copyright 2004-2011 Internet Systems Consortium.
All rights reserved.
For info, please visit https://www.isc.org/software/dhcp/
Listening on LPF/eth0/00:80:ad:0a:06:06
Sending on LPF/eth0/00:80:ad:0a:06:06
Sending on Socket/fallback
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 8
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 20
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 13
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 10
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 10
No DHCPOFFERS received.
No working leases in persistent database - sleeping.
ifup: interface eth0 already configured
done.
root@olddeb:/etc/init.d# ifconfig
eth0 Link encap:Ethernet HWaddr 00:80:ad:0a:06:06
adr inet6: fe80::280:adff:fe0a:606/64 Scope:Lien
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:7 errors:0 dropped:0 overruns:0 frame:0
TX packets:30 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 lg file transmission:1000
RX bytes:944 (944.0 B) TX bytes:3869 (3.7 KiB)
Interruption:18 Adresse de base:0xd400
lo Link encap:Boucle locale
inet adr:127.0.0.1 Masque:255.0.0.0
adr inet6: ::1/128 Scope:Hôte
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:8 errors:0 dropped:0 overruns:0 frame:0
TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 lg file transmission:0
RX bytes:480 (480.0 B) TX bytes:480 (480.0 B)
toujours pas d’ip
second test d’arrêt relance du service réseaux
root@olddeb:/etc/init.d# ./networking stop
[....] Deconfiguring network interfaces...Internet Systems Consortium DHCP Client 4.2.2
Copyright 2004-2011 Internet Systems Consortium.
All rights reserved.
For info, please visit https://www.isc.org/software/dhcp/
Listening on LPF/eth0/00:80:ad:0a:06:06
Sending on LPF/eth0/00:80:ad:0a:06:06
Sending on Socket/fallback
DHCPRELEASE on eth0 to 192.168.0.254 port 67
send_packet: Network is unreachable
send_packet: please consult README file regarding broadcast address.
done.
root@olddeb:/etc/init.d# ./networking start
[....] Configuring network interfaces...Internet Systems Consortium DHCP Client 4.2.2
Copyright 2004-2011 Internet Systems Consortium.
All rights reserved.
For info, please visit https://www.isc.org/software/dhcp/
Listening on LPF/eth0/00:80:ad:0a:06:06
Sending on LPF/eth0/00:80:ad:0a:06:06
Sending on Socket/fallback
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 4
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 9
DHCPDISCOVER on eth0 to 255.255.255.255 port 67 interval 8
DHCPREQUEST on eth0 to 255.255.255.255 port 67
DHCPOFFER from 192.168.0.254
DHCPACK from 192.168.0.254
bound to 192.168.0.14 -- renewal in 342014 seconds.
ifup: interface eth0 already configured
done.
et la, sans aucune raison particulière maintenant ça fonctionne 
[code]
root@olddeb:/etc/init.d# ifconfig
eth0 Link encap:Ethernet HWaddr 00:80:ad:0a:06:06
inet adr:192.168.0.14 Bcast:192.168.0.255 Masque:255.255.255.0
adr inet6: fe80::280:adff:fe0a:606/64 Scope:Lien
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:16 errors:0 dropped:0 overruns:0 frame:0
TX packets:93 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 lg file transmission:1000
RX bytes:3104 (3.0 KiB) TX bytes:14025 (13.6 KiB)
Interruption:18 Adresse de base:0xd400
lo Link encap:Boucle locale
inet adr:127.0.0.1 Masque:255.0.0.0
adr inet6: ::1/128 Scope:Hôte
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:8 errors:0 dropped:0 overruns:0 frame:0
TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 lg file transmission:0
RX bytes:480 (480.0 B) TX bytes:480 (480.0 B)
[\code]
je tente un arret/relance de ma machine pour voir si j’ai le même résultat.