route print help how to route packets through linux box

[tremmarc]

Hi guys!

I have 2 windows xp boxes and linux box, i want my linux box to be
router. Linux runs dhcp server too

but im having trouble routing packets from windows box to linux

heres route table of windows xp box

Active Routes:
Network Destination Netmask Gateway Interface
Metric
0.0.0.0 0.0.0.0 192.168.0.3
192.168.0.200 20
127.0.0.0 255.0.0.0 127.0.0.1
127.0.0.1 1
192.168.0.0 255.255.255.0 192.168.0.200
192.168.0.200 20
192.168.0.200 255.255.255.255 127.0.0.1
127.0.0.1 20
192.168.0.255 255.255.255.255 192.168.0.200
192.168.0.200 20
224.0.0.0 240.0.0.0 192.168.0.200
192.168.0.200 20
255.255.255.255 255.255.255.255 192.168.0.200
3 1
255.255.255.255 255.255.255.255 192.168.0.200
192.168.0.200 1
Default Gateway: 192.168.0.3
===========================================================================
Persistent Routes:
None


ok now,

i want to do the following to route destination 192.168.0.0 with
netmask 255.255.255.0 to use gateway of 192.168.0.3

but as we can see

192.168.0.0 255.255.255.0 192.168.0.200 192.168.0.200 20

that means that is routed direcly without using router,

im wondering is that possible to delete this line ? and add my
personal route as i described?

or any other workaround is apprechiated.

Thanks

 

[Steven L Umbach]

You don't need a router for traffic on your same network. A router is used
to send traffic from one network to another as in you are on 192.168.0.x and
you want to communicate with a computer on 192.168.15.x.

Steve

 

[tremmarc]

You don't need a router for traffic on your same network. A router is used
to send traffic from one network to another as in you are on 192.168.0.x and
you want to communicate with a computer on 192.168.15.x.

Steve

What im trying to accomplish is this:

I want to route whole traffic from whole network 192.168.0.x to go
through specific computer on the same network 192.168.0.3 so i can
filter specific traffic.

but since its on 192.168.0.0 255.255.255.0 192.168.0.200
192.168.0.200 20 windows box

that means its directly attached computer and it wont go through the
router.

Any idea how to accomplish this?

Thanks!

 

[Steven L Umbach]

If that is your goal then one option would be to create two networks and
route the traffic through your router. The other option would be to use
host/software firewalls to filter traffic between computers on the same
network. I can't think of any way to do it that way you want but that
certainly does not mean it is not possible. I believe something like
Microsoft ISA may be able to do what you want and you can download and try
it for free. You may also want to post on a Linux networking forum.

Steve

 

[tremmarc]

If that is your goal then one option would be to create two networks and
route the traffic through your router. The other option would be to use
host/software firewalls to filter traffic between computers on the same
network. I can't think of any way to do it that way you want but that
certainly does not mean it is not possible. I believe something like
Microsoft ISA may be able to do what you want and you can download and try
it for free. You may also want to post on a Linux networking forum.

Steve

Thats what i was thinking, about first option, however second option
is what i would like to try out!

Thanks for your advice, if u come accross the second option feel free
to post!

 

[Steven L Umbach]

Just a though on your first post. Though I have not tried it myself you
could try deleting the default route for your network and then adding the
one that you want for your network specifying the new gateway. Just remember
to use the -p option with route add to keep the new routing entry after a
reboot.

Steve

 

[tremmarc]

original route 192.168.0.0 with gateway 192.168.0.201 i wasnt able to
remove - thats default. And thats what i asked in the first post, that
would suffice if i was able to remove, however that line is removed
only if i disable nic. but then computer isnt able to communicate with
the rest of the subnet.

however i found a solution, with linux, yet i havent tried that no
nics available atm

the thing is on linux i must use ebtables with bridging nics to
achieve that one computer (linux) controls the traffic from one
subnet

thanks!

 

[Steven L Umbach]

Hey that sounds very promising. Thanks for reporting back what will work and
I am sure you will have it working shortly.

Steve