How to properly configure a tun/tap Interface in linux?

Basically I am trying to create a custom TCP Stack. As you might know I cant use eth0 because linux kernel TCP stack uses that, Due to that I need to create a tun/tap interface and use it for my Custom TCP Stack. /etc/network/interfaces: auto lo iface lo inet loopback allow-hotplug eth0 auto eth0 iface eth0 inet static address 192.168.1.152 netmask 255.255.255.0 broadcast 192.168.1.255 gateway 192.168.1.1 dns-server 192.168.1.1 allow-hotplug tap0 auto tap0 iface tap0 inet manual pre-up ip tuntap add tap0 mode tap user root pre-up ip addr add 192.168.1.153/24 dev tap0 up ip link set dev tap0 up post-up ip route del 192.168.1.0/24 dev tap0 post-up ip route add 192.168.1.152/32 dev tap0 post-down ip link del dev tap0 ifconfig inet addr:192.168.1.152 bcast:192.168.1.255 netmask 255.255.255.0 lo: inet addr:127.0.0.1 mask 255.0.0.0 tap0: inet addr: 192.168.1.153 bcast:0.0.0.0 mask 255.255.255.0 with following config I can reach wan/lan using eth0 but I cant reach not even my gateway with tap0. I would really appreciate if you could tell me what mistake am I making here?