UML (UserModeLinux) networking problem

Hi Linuxers,

sorry to post this in 3 different news-groups, but I have no clou
which group would be the right one to ask.

I have a problem with UML and networking.
I try to setup a network connection between the UML virtuel machine
and the host but I don't get connection between them.

I can configure the eth0 device within UML using ifconfig and
I see the tap-device on the host. Seems to me, that the UML helper
programs (like uml_net) are working.
Both interfaces (UML and host) are up and routes are configured to the
devices with the apropriate network-addresses.

If I start tcpdump on both 'machines' and try pings between them, I
can see ARP-requests at the origin. But I don't receive any tcpdump
output at the destination and the target is unreachable.

What can I do/check to get the connection working ?
Could there be something missing within the host kernel ?

By the way, yes I know I can mount the host's filesystem on the UML
virual machine, but this is not what I want or need. I need the
possibility to initiate commands (e.g. via rsh) at the UML machine
from the/a host.

Any help/suggestion is welcome.

Thanks in advance
    Guenter


The facts:

host-kernel:  linux 2.4.18
UML-kernel:   user_mode_linux-2.4.18.36um-0
               executable downloaded form UML homepage (rpm package)
command on host: ping 192.169.10.10
command on UML:  ping 192.168.10.100

ifconfig from host:
-------------------
eth0      Link encap:Ethernet  HWaddr 00:04:76:EA:99:46
           inet addr:129.23.12.160  Bcast:129.23.15.255  Mask:255.255.252.0
           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
           RX packets:5969070 errors:0 dropped:0 overruns:81 frame:0
           TX packets:6075222 errors:0 dropped:0 overruns:0 carrier:0
           collisions:691821 txqueuelen:100
           RX bytes:2746909112 (2619.6 Mb)  TX bytes:2242485986 (2138.6 Mb)
           Interrupt:11 Base address:0x3400

lo        Link encap:Local Loopback
           inet addr:127.0.0.1  Mask:255.0.0.0
           UP LOOPBACK RUNNING  MTU:16436  Metric:1
           RX packets:21075 errors:0 dropped:0 overruns:0 frame:0
           TX packets:21075 errors:0 dropped:0 overruns:0 carrier:0
           collisions:0 txqueuelen:0
           RX bytes:1602048 (1.5 Mb)  TX bytes:1602048 (1.5 Mb)

tap0      Link encap:Ethernet  HWaddr FE:FD:00:00:00:00
           inet addr:192.168.10.100  Bcast:192.168.10.255
Mask:255.255.255.255
           UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
           RX packets:0 errors:0 dropped:0 overruns:0 frame:0
           TX packets:148 errors:0 dropped:0 overruns:0 carrier:0
           collisions:0 txqueuelen:0
           RX bytes:0 (0.0 b)  TX bytes:17840 (17.4 Kb)
           Interrupt:5


ifconfig from UML:
------------------
eth0      Link encap:Ethernet  HWaddr FE:FD:C0:A8:0A:0A
           inet addr:192.168.10.10  Bcast:192.168.10.255  Mask:255.255.255.0
           UP BROADCAST RUNNING MULTICAST  MTU:1484  Metric:1
           RX packets:1 errors:0 dropped:0 overruns:0 frame:0
           TX packets:6 errors:0 dropped:0 overruns:0 carrier:0
           collisions:0 txqueuelen:100
           RX bytes:28 (28.0 b)  TX bytes:264 (264.0 b)
           Interrupt:5

lo        Link encap:Local Loopback
           inet addr:127.0.0.1  Mask:255.0.0.0
           UP LOOPBACK RUNNING  MTU:16436  Metric:1
           RX packets:18 errors:0 dropped:0 overruns:0 frame:0
           TX packets:18 errors:0 dropped:0 overruns:0 carrier:0
           collisions:0 txqueuelen:0
           RX bytes:1628 (1.5 Kb)  TX bytes:1628 (1.5 Kb)


route from host:
----------------
Destination     Gateway         Genmask         Flags Metric Ref    Use
Iface
192.168.10.0    *               255.255.255.0   U     0      0        0 tap0
mchm_32         *               255.255.252.0   U     0      0        0 eth0
loopback        *               255.0.0.0       U     0      0        0 lo
default         mmma.ma.     0.0.0.0         UG    0      0        0 eth0

route from UML:
---------------
Destination     Gateway         Genmask         Flags Metric Ref    Use
Iface
192.168.10.0    *               255.255.255.0   U     0      0        0 eth0