When eth0 is set to static IP or DHCP then eth0:avahi looses it's local connections

[Georgios Kolomvos]

My ubuntu 7.10 pc connects to the Internet through a USB ADSL modem
(ppp0). I want to share this Internet connection with a windows vista pc
that connects to my ubuntu pc with a crossover ethernet cable. This
local connection seems to work fine since both PCs see each other. The
ethernet interface used by the ubuntu pc for the local connection is
eth:avahi and it works fine as long as the setting of eth0 is "enable
roaming mode" (it is not possible to set any settings on eth:avahi from
Network Tools because "the interface does not exist..."). But in this
case (when eth0 is set to "enable roaming mode"), eth0 does not have any
IP address (Network manager shows that it has 0.0.0.0 as IP address). So
when i try to start a firewall through Firestarter (so that i could
"Enable Internet connection sharing"), the firewall cannot start because
"The device eth0 is not ready" (it is logical since it's IP address is
0.0.0.0).

When i try to set eth0 to static IP or DHCP, then the firewall Starts
nicely but interface eth0:avahi looses its IP address and the local
connection with the windows pc is lost. It seems that eth0:avahi
interface works properly only when the setting for eth0 is "enable
roaming mode" (in this case there isn't any entry for eth0 in
/etc/network/interfaces file).

I have read a lot about "ethX:avahi" bugs and problems on the Internet
bit i haven't solved the problem yet.

Does anyone has any idea about what is happening here and what else
should i try?
thank you for reading my message

Georgios Kolomvos
Patras, Greece

P.S. ifconfig output follows to help you understand the problem better

ubuntu-pc:~$ ifconfig
eth0 Link encap:Ethernet HWaddr 00:16:E6:84:BE:4C
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:707 errors:0 dropped:0 overruns:0 frame:0
TX packets:201 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:55521 (54.2 KB) TX bytes:37940 (37.0 KB)
Interrupt:16

eth0:avah Link encap:Ethernet HWaddr 00:16:E6:84:BE:4C
inet addr:169.254.167.197 Bcast:169.254.255.255 Mask:255.255.0.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
Interrupt:16

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:112 errors:0 dropped:0 overruns:0 frame:0
TX packets:112 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:9416 (9.1 KB) TX bytes:9416 (9.1 KB)

ppp0 Link encap:Point-to-Point Protocol
inet addr:77.49.12.191 P-t-P:194.219.252.143
Mask:255.255.255.255
UP POINTOPOINT RUNNING NOARP MULTICAST MTU:1500 Metric:1
RX packets:2898 errors:0 dropped:0 overruns:0 frame:0
TX packets:2729 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:3
RX bytes:1970909 (1.8 MB) TX bytes:283584 (276.9 KB)

vmnet1 Link encap:Ethernet HWaddr 00:50:56:C0:00:01
inet addr:192.168.219.1 Bcast:192.168.219.255 Mask:255.255.255.0
inet6 addr: fe80::250:56ff:fec0:1/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:199 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)

vmnet8 Link encap:Ethernet HWaddr 00:50:56:C0:00:08
inet addr:172.16.71.1 Bcast:172.16.71.255 Mask:255.255.255.0
inet6 addr: fe80::250:56ff:fec0:8/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:199 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)

[Nils Kassube]

Post by Georgios Kolomvos
My ubuntu 7.10 pc connects to the Internet through a USB ADSL modem
(ppp0). I want to share this Internet connection with a windows vista
pc that connects to my ubuntu pc with a crossover ethernet cable. This
local connection seems to work fine since both PCs see each other. The
ethernet interface used by the ubuntu pc for the local connection is
eth:avahi and it works fine as long as the setting of eth0 is "enable
roaming mode" (it is not possible to set any settings on eth:avahi from
Network Tools because "the interface does not exist..."). But in this
case (when eth0 is set to "enable roaming mode"), eth0 does not have
any IP address (Network manager shows that it has 0.0.0.0 as IP
address). So when i try to start a firewall through Firestarter (so
that i could "Enable Internet connection sharing"), the firewall cannot
start because "The device eth0 is not ready" (it is logical since it's
IP address is 0.0.0.0).
When i try to set eth0 to static IP or DHCP, then the firewall Starts
nicely but interface eth0:avahi looses its IP address and the local
connection with the windows pc is lost. It seems that eth0:avahi
interface works properly only when the setting for eth0 is "enable
roaming mode" (in this case there isn't any entry for eth0 in
/etc/network/interfaces file).

Your problem seems to be that eth0:avahi is a virtual interface especially
made for roaming mode, but it uses the physical interface eth0. I think,
roaming mode is not necessarily useful in your situation - better use
eth0 with a static setup. That would be about this procedure (I haven't
tested it):

- Unselect roaming mode.
- Use the network tools to give your eth0 an IP address 192.168.2.3 and a
network mask 255.255.255.0.
- Setup your Linux machine for "connection sharing" with firestarter, as
you intended to do.
- Setup your Windows machine to use a static IP address 192.168.2.4,
network mask 255.255.255.0 and gateway your Linux machine (192.168.2.3).

Please note: I made the assumption that you know how to use the network
tools and firestarter which you mentioned. If you need more help with it,
please let us know.


Nils