Getting IPv6 packages when setting a newly created TAP device up

I'm trying to learn how to TCP works by creating a TCP/IP stack, and as the title says, I'm programmatically creating a TAP device in Rust as follows ```rs pub struct Tap { fd: i32, } #[repr(C)] struct IFreq { name: [c_char; IFNAMSIZ], flags: c_short, } impl Tap { pub fn new(name: &CStr) -> Result { let fd = unsafe { let fd = libc::open(b"/dev/net/tun\0".as_ptr() as *const _, libc::O_RDWR); if fd up` and started reading ethernet frames I seem to only be getting IPv6 frames (ethertype is 0x86DD). Is this normal? How do I stop this from happening? I'm currently only working on implementing IPv4 and don't want to deal with IPv6 traffic.