------
MN | (eth0=192.168.1.3) -----------| gw 192.168.1.10
------ |
| |
(switch) |
| |
------ (eth0=192.168.1.2) | gw 192.168.1.10
HA | |
------ (eth1=192.168.1.5) | gw 192.168.1.10
| |
| |
-------- (eth0=192.168.1.10) | gw 0.0.0.0
pc router| |
-------- (eth1=192.168.2.20) | gw 0.0.0.0
| |
| |
------ (eth1=192.168.2.5) | gw 192.168.2.20
FA | |
------ (eth0=192.168.2.1) | gw 192.168.2.20
| |
(switch) |
| |
------- |
MN moves <--------------------------|
-------

MN:
IP address: 192.168.1.3
netmask: 255.255.255.0
network: 192.168.1.0
gateway: 192.168.1.10

HA:
IP address: 192.168.1.2 (eth0)
IP address: 192.168.1.5 (eth1)
netmask: 255.255.255.0
network: 192.168.1.0
gateway: 192.168.1.10

PC router:
IP address: 192.168.1.10 (eth0)
IP address: 192.168.2.20 (eth1)
netmask: 255.255.255.0
network: 192.168.1.0
network: 192.168.2.0
gateway: 0.0.0.0

FA:
IP address: 192.168.2.1 (eth0)
IP address: 192.168.2.5 (eth1)
netmask: 255.255.255.0
network: 192.168.2.0
gateway: 192.168.1.10

The result is that FA, PC router and HA can ping each other... but the MN can not ping to HA...

i can only successfully ping the MN to HA when I switch eth0 "ifup the eth0"...in this case, the HA is failed and can not connect the PC router and FA...

How can I make it so that the MN can also connect to MN and PC router without switch the eth? Can someone tell me the problem?

I noticed one thing:

HA and FA are routers as well, but the interfaces on those computers belong to the same subnet. Any packets for that subnet might go out one port or the other. (And according to Murphy it's always the wrong one).

Each interface must belong to another subnet.

If MN pings HA, HA might react but sends the reply via the wrong interface (if both interfaces are up). If you shut one interface down, only one interface remains responsible for that subnet.

Try creating a third subnet for MN and configure HA accordingly.

Thanks vimico,

I have a project using dynamic-0.8.1 software to implement Mobile IP testbed.
After discuss with my supervisor, i have to setup two different network (subnet) which is separated by a PC router, to foreign network and home network. As you said, both FA and HA is act as router as well...

since I'm just have basic knowledge for networking, can you advise me how to handle this condition.. I have to proof that Mobile IP implementation where the MN can stay the connection with IP address after move the foreign network... I think I have to use two different subnet to apply it...

Can you tell me if you have any suggestion for it? Can I make it without third network? Or it is required for third subnet? Or there is other way to make the HA and FA not to be router?? would it possible?

How about the connection like this as below (wired network)?

|MN|------|Hub|------|HA|
|------------|
|------------|
|------------| (192.168.1.10)
|-------|pc router|
|------------| (192.168.2.20)
v------------|
-------------|
|MN|------|Hub|-----|FA|

before:
|MN|----------
--| -----------|
--| -----------|
|switch|-------|
--|------------|
--|------------|
|HA|-----------|
--|------------|
--|.1.10-------|
|router|-------|
--|.2.20-------|
--|------------|
|FA|-----------|
--|------------|
--|------------|
|swtich|-------|
--|------------|
--|------------|
MN move<----

Can I ask one more thing? How to send or copy file from PcA to PcB in Linux RH if two pcs are connected? Just like copy and transfer file in Window by share document.. For Linux, how it work?

hi,on your second question, in text mode you can use scp to copy or send files across a linux network.. Say PcA = 192.168.1.1 and PcB is 192.168.1.2, want to send a file called xxx from /home on pcA to pcb. Then go to pcA and type :

scp /home/xxx root@192.168.1.2:/home/xxx

for file from pcB to a and you are on pcA :

scp root@192.168.1.2:/home/xxx /home/xxx


Hope it helps

I'm not sure what you want to achieve. I presume you want to move MN from one net to the other without changing its IP address. This will not be possible.

If you have multiple ethernet cards, you need different subnets, so that the router can decide, if a given data packets has to go to card A or card B. If the IP address of MN is in the subnet of card A, packets for MN will be routed via that card (and not via card B). If you disconnect MN, and connect if directly (or indirectly via a switch) to card B, packets for MN will still be routed via card A and MN will never hear them.

If you connect MN to card B, MN must have an IP address from the subnet of card B, otherwise communication will not work.

Hint: Usually DHCP servers are used to dynamically assign IP addresses.