Using Juniper EX3300 as a router [duplicate]

Possible Duplicate:
Using the Juniper EX3300 Switch as a router?

So I have a Juniper EX3300 Switch. One of its uplink ports (ge-0/1/0) is connected to my ISP's router. ISP router's port address is xx.xx.xx.109. My switch's IP address is xx.xx.xx.110.

From the switch, I can ping to xx.xx.xx.109 and any other IP in the world. I mean its connected to the Internet.

I connected the port eth0 of a computer (running Ubuntu) to the port ge-0/0/0 of the switch (which in the same VLAN as ge-0/1/0). I configured the port eth0 as follows:

iface eth0 inet static
    address yy.yy.yy.208
    netmask 255.255.255.240
    gateway xx.xx.xx.110

yy.yy.yy.208 is assigned to me by the ISP. So, now I can ping to the switch (xx.xx.xx.110) from this computer. But I can not ping to either xx.xx.xx.109 (ISP router) or any other IP.

I want this computer to be connected to the Internet. What am I doing wrong?

Here are some of the configurations on my switch:

interfaces {
    ge-0/0/0 {
        unit 0 {
            family ethernet-switching;
        }
    }
    .
    .
    .
    ge-0/1/0 {
        ether-options {
            no-auto-negotiation;
            link-mode full-duplex;
            speed {
                1g;
            }
        }
        unit 0 {
            family ethernet-switching {
                port-mode access;
            }
        }
    }
    .
    .
    .
    vlan {
        unit 0 {
            family inet {
                address 10.0.1.1/24;
            }
        }
        unit 1 {
            family inet {
                address xx.xx.xx.110/30;
            }
        }
    }
}
.
.
.
routing-options {
    static {
        route 0.0.0.0/0 {
            next-hop xx.xx.xx.109;
            retain;
        }
    }
}
vlans {
    Cogent {
        vlan-id 3;
        interface {
            ge-0/1/0.0;
            ge-0/0/0.0;
            ge-0/0/1.0;
            ge-0/0/2.0;
            ge-0/0/3.0;
        }
        l3-interface vlan.1;
    }
    TFLan {
        vlan-id 2;
        interface {
            ge-0/0/5.0;
            ge-0/0/6.0;
            ge-0/0/7.0;
            ge-0/0/8.0;
            ge-0/0/9.0;
            ge-0/0/10.0;
            ge-0/0/11.0;
            ge-0/0/12.0;
            ge-0/0/13.0;
            ge-0/0/14.0;
            ge-0/0/15.0;
            ge-0/0/16.0;
            ge-0/0/17.0;
            ge-0/0/18.0;
            ge-0/0/19.0;
            ge-0/0/20.0;
            ge-0/0/21.0;
            ge-0/0/22.0;
            ge-0/0/23.0;
            ge-0/0/4.0;
        }
        l3-interface vlan.0;
    }
}