Linux and Inter-vlan Routing

["Mahdi Rahimi" <rahimi@eaedu.net>]

Hi dears...


I Have 10 switch cisco 2950T that connect via 802.1q protocol togather,
and don't have any Layer 3 switch or Router. I want to know Linux box can
act as layer 3 device with below config or can inter-vlan Routing???

My Intranet interface is the VLAN 1. (eth0)
My Lan Interface face the VLAN 2. (eth1)
My DMZ interface face the VLAN 3. (eth2)

eth0 (linux)  ->  switch (fas0/1)  (switchport mode trunk )
eth1  (linux)  -> switch (fas0/2)  (switchport access vlan 2)
eth2 (linux)  -> switch (fas0/3)   (switchport access vlan 3)
////////
Intranet: 192.168.100.0/24 (for switch management)
LAN: 172.16.3.0/24
DMZ: 192.168.1.0/24
/////////
I already install VLAN package and config is:
#modprobe 8021q
#vconfig add eth1 2
#vconfig add eth2 3

My interface scripts is:

auto eth0
iface eth0 inet static
        address 192.168.100.91
        netmask 255.255.255.0
        vlan_raw_device eth0

auto eth1
iface eth1 inet static
        address 172.16.3.1
        netmask 255.255.255.0
        network 172.16.3.0
        broadcast 172.16.3.255
        vlan_raw_device eth0

iface eth2 inet static
        address 192.168.1.192
        netmask 255.255.255.0
        network 192.168.1.0
        broadcast 192.168.1.255
        gateway 192.168.1.1
        vlan_raw_device eth0


Iptables:
(192.168.1.80 is our sql-server)
*nat
-A PREROUTING -s 172.16.3.0/255.255.255.0 -d 192.168.1.80 -p tcp -m multiport
--dports 1433 -j ACCEPT

-A POSTROUTING -s 172.16.3.0/255.255.255.0 -d 192.168.1.80 -j MASQUERADE

*filter
-A FORWARD -i eth1 -o eth2 -m state --state NEW,RELATED,ESTABLISHED -j ACCEPT
-A FORWARD -i eth2 -o eth1 -m state --state RELATED,ESTABLISHED -j ACCEPT


best regards