Hi,
I have a machine that I have just loaded truV5.1 onto and I have also put
another 10/100 DE500 ethernet card into. We have a network that is based on
a B-class address. The machine is connected to a Cisco something or other.
The Cisco supports vlans, and we currently have the network subdivided into
vlans which reflect the third number if the IP, ie vlan100 includes all ip
address that have the format <1st byte of B-address>.<2nd byte of
B-address>.100.xxx. All unix and PC's are setup with a network mask of
255.255.255.0. So for a packet to go from vlan100 to vlan101 it has to go
through the Cisco router. Currently all the unix workstations are on vlan101
and all PC's within the group are on vlan100.
For those that may not know, from the Cisco point of view all devices
connected to the same vlan can be seen as being connected to the same piece
of wire. So devices can talk to each other at the MAC address level (ie
ethernet card address).
What I want to do is allow the PC's to directly talk to the unix box by
having 2 ethernet cards in the same box, one connected to vlan101 (unix
boxes) the other connected to vlan100 (PCs).
I thought this would be a simple operation, but when I try to configure both
cards the unix box stops talking to the network. The only way to get out of
this, is to reboot the unix box with only one of the cards configured.
Setting up the /etc/rc.config to only configure one card and then running
rcinet doesn't seem to do the trick.
I have looked through my collection of summaries and can only find vague
descriptions of what the problem might be. At first reading of one of the
summaries, it would appear that you can't have 2 different default routes
for the same machine, in the same address space. But I was NOT setting up 2
default routes, because there should be no need for there to be a default
route for the unix box to the PC vlan100.
Is anyone able to point me in a direction of where I can find information on
how IP addresses work, and how if possible could I setup a unix box so that
it is seen as a member of both vlans. Of course one solution would be,
change the configuration at the Cisco so that both vlans are amalgamated
into one, that solution is not within scope I'm afraid.
Dennis
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Dennis Macdonell
Systems Administrator
AUSLIG
mail: PO Box 2, Belconnen, ACT 2617
email: mcdonell_at_auslig.gov.au
ph: 61 2 6201 4326
fax: 61 2 6201 4377
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Received on Mon Apr 09 2001 - 06:54:06 NZST