network-manager clobbering resolv.conf (again!)

[shochatd]

All of a sudden, DNS lookups were failing, and I found that /etc/resolv.conf was empty. And again, if I edit it, and put in some valid DNS server addresses, everything works again until network-manager does its thing again, and then once again, it is empty (except for the comment about network-manager). Last time this happened it was because my network interfaces were not "managed", but this seems to be different. I do have the up and down arrow indicator menu this time. In it, if I select Edit Connections..., I see 3 things: ifupdown(eth1), Wired connection 1, and ifupdwon(eth0). eth1 is the interface that is connected to my router. If I select ifupdown(eth1), Edit... is grayed out (why???). If I select Wired connection 1, Edit... is enabled, so I click on that. ipv4 settings tab has valid settings, including DNS. Why do I have both eth1 and "Wired connection 1"? By the way, /etc/NetworkManager/system-connections has only 1 file, called 'Wired connection 1'. If I restart network-manager, my resolv.conf is clobbered (only the comment). What is going on?
Thanks.
-- David

[fdrake]

try this :
connect the ethernet cable
and post "ifconfig"

then depenfing on the name of your interface do

echo "iface eth0 inet dhcp" | tee -a /etc/network/interfaces

restart NetworkManager and resolv.conf should bot change.

[shochatd]

Thanks for your reply. As I said, the working interface is eth1. Output of ifconfig talks about eth0, eth1, and lo. Note that I'm using static addressing on eth1, so I don't want DHCP. There is already an eth1 section in /etc/network/interfaces. That file has the following:
auto lo
iface lo inet loopback


iface eth0 inet static
address 192.168.1.6
netmask 255.255.255.0

auto eth1
iface eth1 inet static
address 192.168.1.5
netmask 255.255.255.0
gateway 192.168.1.1

Also, 3 more with iface commented out. For eth2 (I don't have that many interfaces!), ath0 (what's that?) and wlan0 (??). Maybe I should try deleting those.

[fdrake]

Thanks for your reply. As I said, the working interface is eth1. Output of ifconfig talks about eth0, eth1, and lo. Note that I'm using static addressing on eth1, so I don't want DHCP. There is already an eth1 section in /etc/network/interfaces. That file has the following:
auto lo
iface lo inet loopback


iface eth0 inet static
address 192.168.1.6
netmask 255.255.255.0

auto eth1
iface eth1 inet static
address 192.168.1.5
netmask 255.255.255.0
gateway 192.168.1.1

Also, 3 more with iface commented out. For eth2 (I don't have that many interfaces!), ath0 (what's that?) and wlan0 (??). Maybe I should try deleting those.

can you post output of:

ifconfig && route && lshw -c network

wlan0 is the wireless ususally, ath0, never heard before maybe is referung to "lo" ? you have too many net interfaces...

[shochatd]

can you post output of:

ifconfig && route && lshw -c network

# ifconfig && route && lshw -c network
eth0      Link encap:Ethernet  HWaddr 00:18:f3:c8:d9:1f  
          UP BROADCAST MULTICAST  MTU:1500  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:0 (0.0 B)  TX bytes:0 (0.0 B)
          Interrupt:21 

eth1      Link encap:Ethernet  HWaddr 00:18:f3:c8:d9:1e  
          inet addr:192.168.1.5  Bcast:192.168.1.255  Mask:255.255.255.0
          inet6 addr: fe80::218:f3ff:fec8:d91e/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:41020 errors:0 dropped:0 overruns:0 frame:0
          TX packets:26184 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:54048001 (54.0 MB)  TX bytes:2590290 (2.5 MB)
          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:4303 errors:0 dropped:0 overruns:0 frame:0
          TX packets:4303 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:342824 (342.8 KB)  TX bytes:342824 (342.8 KB)

Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
default         Wireless_Broadb 0.0.0.0         UG    0      0        0 eth1
link-local      *               255.255.0.0     U     1000   0        0 eth1
192.168.1.0     *               255.255.255.0   U     1      0        0 eth1
  *-network               
       description: Ethernet interface
       product: 88E8052 PCI-E ASF Gigabit Ethernet Controller
       vendor: Marvell Technology Group Ltd.
       physical id: 0
       bus info: pci@0000:03:00.0
       logical name: eth1
       version: 21
       serial: 00:18:f3:c8:d9:1e
       size: 100Mbit/s
       capacity: 1Gbit/s
       width: 64 bits
       clock: 33MHz
       capabilities: pm vpd msi pciexpress bus_master cap_list rom ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=sky2 driverversion=1.28 duplex=full firmware=N/A ip=192.168.1.5 latency=0 link=yes multicast=yes port=twisted pair speed=100Mbit/s
       resources: irq:44 memory:fa9fc000-fa9fffff ioport:c800(size=256) memory:fa9c0000-fa9dffff
  *-network
       description: Ethernet interface
       product: 88E8001 Gigabit Ethernet Controller
       vendor: Marvell Technology Group Ltd.
       physical id: 5
       bus info: pci@0000:01:05.0
       logical name: eth0
       version: 14
       serial: 00:18:f3:c8:d9:1f
       capacity: 1Gbit/s
       width: 32 bits
       clock: 66MHz
       capabilities: pm vpd bus_master cap_list rom ethernet physical tp 10bt 10bt-fd 100bt 100bt-fd 1000bt 1000bt-fd autonegotiation
       configuration: autonegotiation=on broadcast=yes driver=skge driverversion=1.13 firmware=N/A latency=64 link=no maxlatency=31 mingnt=23 multicast=yes port=twisted pair
       resources: irq:21 memory:fa7fc000-fa7fffff ioport:a800(size=256) memory:fa7c0000-fa7dffff

[shochatd]

Here's something I didn't mention before, and may be important. I said before that if I click Edit connections... I see eth1, but Edit... is grayed out (so is Delete...). Here's the thing: If I hover the mouse over Edit..., I see the following:

Authenticate to edit the selected connection

So the obvious question is, HOW am I supposed to initiate this authentication?