Baffling network

[Kevin O'Gorman]

I tried to ask this before, got no answer, and got busy on other
things; now I'm trying again.  So this time, I'd appreciate even
pointers to another place where it might be better to ask this.

My question first: how do I turn off the system's normal network
management and use ifconfig and route directly?  The rest of this
email is intended to show why I want to do that, and boils down to the
fact that the current situation is inconsistent and incomprehensible,
and I'm about to change some stuff and want to be able to tell what's
going on.

I'm running 11.04, fully updated, and pretty much nothing else except
some GDB database programs I wrote in python.  Part of this is
connected to my web server.

I'm trying to switch from DSL with static IPs to cable with DHCP.
I took a look, and don't even understand how the current setup is
working at all;
  - /sbin/route and /sbin/ifconfig show two working interfaces with
the same IP number.  One is connected to my DHCP router on cable.
  - the one "Network Connections" says is carrying traffic (eth0) is
not listed in the output of /sbin/ifconfig or /sbin/route
  - /sbin/ifconfig traffic counts show traffic on both interfaces,
with the same IP numbers and different MAC addresses.
  - one of the connections I *did* configure is not actually running,
if you believe ifconfig.
  - attempts to override this with /sbin/route and /sbin/ifconfig get
reverted to this crazy setup in a few minutes
  - I have no idea why these inconsistencies occur.

Running system->Preferences->Network Connections
shows two wired interfaces (and no other kind), eth0 and eth3.  It
says eth0 is being used now, and eth3 was last used 14 days ago.
Interfaces eth1 and eth2 do not appear at all.  Note how radically
this differs from the reports below.

All of this is constant; it does not change on reboot.

============================================================
The output of /sbin/route
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
64.166.164.48   *               255.255.255.248 U     1      0        0 eth2
64.166.164.48   *               255.255.255.248 U     1      0        0 eth3
link-local      *               255.255.0.0     U     1000   0        0 eth3
default         router          0.0.0.0         UG    0      0        0 eth3


============================================================
The output of /sbin/ifconfig follows.  Note identical IPV4
settings.for two different HWaddrs
eth2      Link encap:Ethernet  HWaddr 8c:89:a5:31:4f:bd
          inet addr:64.166.164.49  Bcast:64.166.164.55  Mask:255.255.255.248
          inet6 addr: fe80::8e89:a5ff:fe31:4fbd/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:415453 errors:0 dropped:0 overruns:0 frame:0
          TX packets:224185 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:28762157 (28.7 MB)  TX bytes:9491096 (9.4 MB)
          Interrupt:77 Base address:0x4000

eth3      Link encap:Ethernet  HWaddr 00:50:ba:5e:d1:1c
          inet addr:64.166.164.49  Bcast:64.166.164.55  Mask:255.255.255.248
          inet6 addr: fe80::250:baff:fe5e:d11c/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:758687 errors:0 dropped:0 overruns:0 frame:0
          TX packets:531099 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:406463015 (406.4 MB)  TX bytes:137469860 (137.4 MB)
          Interrupt:21 Base address:0xd000

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:78201 errors:0 dropped:0 overruns:0 frame:0
          TX packets:78201 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:17244199 (17.2 MB)  TX bytes:17244199 (17.2 MB)


HELP!!!


-- 
Kevin O'Gorman, PhD