diff --git a/network-hypervisor/Cargo.lock b/network-hypervisor/Cargo.lock
index ff63a0c1a..764dd23c3 100644
--- a/network-hypervisor/Cargo.lock
+++ b/network-hypervisor/Cargo.lock
@@ -9,6 +9,12 @@ dependencies = [
  "gcrypt",
 ]
 
+[[package]]
+name = "base64"
+version = "0.13.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "904dfeac50f3cdaba28fc6f57fdcddb75f49ed61346676a78c4ffe55877802fd"
+
 [[package]]
 name = "bitflags"
 version = "1.2.1"
@@ -413,6 +419,7 @@ name = "zerotier-network-hypervisor"
 version = "2.0.0"
 dependencies = [
  "aes-gmac-siv",
+ "base64",
  "ed25519-dalek",
  "gcrypt",
  "rand_core",
diff --git a/network-hypervisor/Cargo.toml b/network-hypervisor/Cargo.toml
index 44939c6d2..154ebf4a3 100644
--- a/network-hypervisor/Cargo.toml
+++ b/network-hypervisor/Cargo.toml
@@ -9,3 +9,4 @@ aes-gmac-siv = { path = "../aes-gmac-siv" }
 x25519-dalek = "^1"
 ed25519-dalek = "^1"
 gcrypt = "^0"
+base64 = "^0"
diff --git a/network-hypervisor/src/crypto/c25519.rs b/network-hypervisor/src/crypto/c25519.rs
index 18a531386..8ae85c288 100644
--- a/network-hypervisor/src/crypto/c25519.rs
+++ b/network-hypervisor/src/crypto/c25519.rs
@@ -1,7 +1,8 @@
 use std::convert::TryInto;
-use ed25519_dalek::Digest;
 use std::io::Write;
 
+use ed25519_dalek::Digest;
+
 pub const C25519_PUBLIC_KEY_SIZE: usize = 32;
 pub const C25519_SECRET_KEY_SIZE: usize = 32;
 pub const C25519_SHARED_SECRET_SIZE: usize = 32;
diff --git a/network-hypervisor/src/crypto/hash.rs b/network-hypervisor/src/crypto/hash.rs
index 2d7de9f96..9b53be1c8 100644
--- a/network-hypervisor/src/crypto/hash.rs
+++ b/network-hypervisor/src/crypto/hash.rs
@@ -3,7 +3,7 @@ use std::convert::TryInto;
 use std::io::Write;
 
 pub const SHA512_HASH_SIZE: usize = 64;
-pub const SHA384_HASH_SIZE: usize = 64;
+pub const SHA384_HASH_SIZE: usize = 48;
 
 pub struct SHA512(gcrypt::digest::MessageDigest);
 
diff --git a/network-hypervisor/src/crypto/p521.rs b/network-hypervisor/src/crypto/p521.rs
index c96438431..72ead04a4 100644
--- a/network-hypervisor/src/crypto/p521.rs
+++ b/network-hypervisor/src/crypto/p521.rs
@@ -131,6 +131,7 @@ impl P521KeyPair {
     }
 
     /// Create an ECDSA signature of the input message.
+    /// Message data does not need to be pre-hashed.
     pub fn sign(&self, msg: &[u8]) -> Option<[u8; P521_ECDSA_SIGNATURE_SIZE]> {
         let data = SExpression::from_str(unsafe { std::str::from_utf8_unchecked(&hash_to_data_sexp(msg)) }).unwrap();
         gcrypt::pkey::sign(&self.secret_key_for_ecdsa, &data).map_or(None, |sig| {
@@ -171,6 +172,8 @@ impl P521PublicKey {
         }
     }
 
+    /// Verify a signature.
+    /// Message data does not need to be pre-hashed.
     pub fn verify(&self, msg: &[u8], signature: &[u8]) -> bool {
         if signature.len() == P521_ECDSA_SIGNATURE_SIZE {
             let data = SExpression::from_str(unsafe { std::str::from_utf8_unchecked(&hash_to_data_sexp(msg)) }).unwrap();
diff --git a/network-hypervisor/src/lib.rs b/network-hypervisor/src/lib.rs
index 5e5d45548..86b0e1063 100644
--- a/network-hypervisor/src/lib.rs
+++ b/network-hypervisor/src/lib.rs
@@ -2,3 +2,4 @@ pub mod crypto;
 pub mod vl1;
 pub mod util;
 pub mod error;
+pub mod vl2;
diff --git a/network-hypervisor/src/util/mod.rs b/network-hypervisor/src/util/mod.rs
index ce02e677d..05eadb521 100644
--- a/network-hypervisor/src/util/mod.rs
+++ b/network-hypervisor/src/util/mod.rs
@@ -1 +1,42 @@
 pub mod hex;
+
+#[inline(always)]
+pub(crate) fn integer_store_be_u16(i: u16, d: &mut [u8]) {
+    d[0] = (i >> 8) as u8;
+    d[1] = i as u8;
+}
+
+#[inline(always)]
+pub(crate) fn integer_store_be_u32(i: u32, d: &mut [u8]) {
+    d[0] = (i >> 24) as u8;
+    d[1] = (i >> 16) as u8;
+    d[2] = (i >> 8) as u8;
+    d[3] = i as u8;
+}
+
+#[inline(always)]
+pub(crate) fn integer_store_be_u64(i: u64, d: &mut [u8]) {
+    d[0] = (i >> 56) as u8;
+    d[1] = (i >> 48) as u8;
+    d[2] = (i >> 40) as u8;
+    d[3] = (i >> 32) as u8;
+    d[4] = (i >> 24) as u8;
+    d[5] = (i >> 16) as u8;
+    d[6] = (i >> 8) as u8;
+    d[7] = i as u8;
+}
+
+#[inline(always)]
+pub(crate) fn integer_load_be_u16(d: &[u8]) -> u16 {
+    (d[0] as u16) << 8 | (d[1] as u16)
+}
+
+#[inline(always)]
+pub(crate) fn integer_load_be_u32(d: &[u8]) -> u32 {
+    (d[0] as u32) << 24 | (d[1] as u32) << 16 | (d[2] as u32) << 8 | (d[3] as u32)
+}
+
+#[inline(always)]
+pub(crate) fn integer_load_be_u64(d: &[u8]) -> u64 {
+    (d[0] as u64) << 56 | (d[1] as u64) << 48 | (d[2] as u64) << 40 | (d[3] as u64) << 32 | (d[4] as u64) << 24 | (d[5] as u64) << 16 | (d[6] as u64) << 8 | (d[7] as u64)
+}
diff --git a/network-hypervisor/src/vl1/address.rs b/network-hypervisor/src/vl1/address.rs
index 2370466ac..0c985e988 100644
--- a/network-hypervisor/src/vl1/address.rs
+++ b/network-hypervisor/src/vl1/address.rs
@@ -13,7 +13,7 @@ impl Address {
     #[inline(always)]
     pub fn from_bytes(b: &[u8]) -> Result<Address, InvalidFormatError> {
         if b.len() >= 5 {
-            Ok(Address((b[0] as u64) << 32 | (b[1] as u64) << 24 | (b[2] as u64) << 16 | (b[3] as u64) << 8 as u64 | b[4] as u64))
+            Ok(Address((b[0] as u64) << 32 | (b[1] as u64) << 24 | (b[2] as u64) << 16 | (b[3] as u64) << 8 | b[4] as u64))
         } else {
             Err(InvalidFormatError("invalid ZeroTier address"))
         }
@@ -25,13 +25,13 @@ impl Address {
     }
 
     #[inline(always)]
-    pub fn is_valid(&self) -> bool {
-        self.0 != 0 && !self.is_reserved()
+    pub fn is_nil(&self) -> bool {
+        self.0 == 0
     }
 
     #[inline(always)]
-    pub fn is_nil(&self) -> bool {
-        self.0 == 0
+    pub fn is_valid(&self) -> bool {
+        !self.is_nil() && !self.is_reserved()
     }
 
     #[inline(always)]
@@ -46,7 +46,6 @@ impl Address {
 }
 
 impl ToString for Address {
-    #[inline(always)]
     fn to_string(&self) -> String {
         let mut v = self.0 << 24;
         let mut s = String::new();
@@ -62,7 +61,6 @@ impl ToString for Address {
 impl FromStr for Address {
     type Err = InvalidFormatError;
 
-    #[inline(always)]
     fn from_str(s: &str) -> Result<Self, Self::Err> {
         Address::from_bytes(crate::util::hex::from_string(s).as_slice())
     }
@@ -85,7 +83,7 @@ impl Hash for Address {
 impl From<&[u8; 5]> for Address {
     #[inline(always)]
     fn from(b: &[u8; 5]) -> Address {
-        Address((b[0] as u64) << 32 | (b[1] as u64) << 24 | (b[2] as u64) << 16 | (b[3] as u64) << 8 as u64 | b[4] as u64)
+        Address((b[0] as u64) << 32 | (b[1] as u64) << 24 | (b[2] as u64) << 16 | (b[3] as u64) << 8 | b[4] as u64)
     }
 }
 
diff --git a/network-hypervisor/src/vl1/buffer.rs b/network-hypervisor/src/vl1/buffer.rs
index f0a246cc2..3dd4619d3 100644
--- a/network-hypervisor/src/vl1/buffer.rs
+++ b/network-hypervisor/src/vl1/buffer.rs
@@ -1,8 +1,6 @@
 use std::mem::size_of;
 use std::marker::PhantomData;
-
-const FAULT_BIT: usize = 1_usize << ((size_of::<usize>() * 8) - 1);
-const FAULT_CLEAR_MASK: usize = !FAULT_BIT;
+use std::io::Write;
 
 /// Annotates a type as containing only primitive types like integers and arrays.
 /// This means it's safe to abuse with raw copy, raw zero, or "type punning."
@@ -19,13 +17,6 @@ unsafe impl RawObject for NoHeader {}
 /// This also supports a generic header that must be a RawObject and will always be
 /// placed at the beginning of the buffer. When you construct or clear() a buffer
 /// space will be maintained for the header. Use NoHeader if you don't want a header.
-///
-/// If a write overflow occurs during append operations, the operations fail silently
-/// without increasing the buffer's size and an internal fault bit is set. The
-/// check_overflow() method must be used before the buffer is actually complete to
-/// ensure that no write overflows occurred. If this check isn't performed a buffer
-/// could be used with incomplete or corrupt data, but no crash or memory errors will
-/// occur.
 #[derive(Clone)]
 pub struct Buffer<H: RawObject, const L: usize>(usize, [u8; L], PhantomData<H>);
 
@@ -34,7 +25,6 @@ unsafe impl<H: RawObject, const L: usize> RawObject for Buffer<H, L> {}
 impl<H: RawObject, const L: usize> Default for Buffer<H, L> {
     #[inline(always)]
     fn default() -> Self {
-        assert!(size_of::<H>() <= L);
         Buffer(size_of::<H>(), [0_u8; L], PhantomData::default())
     }
 }
@@ -45,125 +35,285 @@ impl<H: RawObject, const L: usize> Buffer<H, L> {
         Self::default()
     }
 
-    /// Returns true if there has been a write overflow.
-    #[inline(always)]
-    pub fn check_overflow(&self) -> bool {
-        (self.0 & FAULT_BIT) != 0
-    }
-
     /// Get a slice containing the entire buffer in raw form including the header.
     #[inline(always)]
     pub fn as_bytes(&self) -> &[u8] {
-        &self.1[0..(self.0 & FAULT_CLEAR_MASK)]
+        &self.1[0..self.0]
     }
 
     /// Erase contents and reset size to the size of the header.
     #[inline(always)]
     pub fn clear(&mut self) {
+        self.1[0..self.0].fill(0);
         self.0 = size_of::<H>();
-        self.1.fill(0);
     }
 
     /// Get the length of this buffer (including header, if any).
     #[inline(always)]
     pub fn len(&self) -> usize {
-        self.0 & FAULT_CLEAR_MASK
+        self.0
     }
 
     /// Get a reference to the header (in place).
     #[inline(always)]
     pub fn header(&self) -> &H {
+        debug_assert!(size_of::<H>() <= L);
         unsafe { &*self.1.as_ptr().cast::<H>() }
     }
 
     /// Get a mutable reference to the header (in place).
     #[inline(always)]
     pub fn header_mut(&mut self) -> &mut H {
+        debug_assert!(size_of::<H>() <= L);
         unsafe { &mut *self.1.as_mut_ptr().cast::<H>() }
     }
 
-    /// Append a packed structure and initializing it in place via the supplied function.
-    ///
-    /// If an overflow occurs the overflow fault bit is set internally (see check_overflow())
-    /// and the supplied function will never be called.
+    /// Append a packed structure and call a function to initialize it in place.
+    /// Anything not initialized will be zero.
     #[inline(always)]
-    pub fn append_and_init_struct<T: RawObject, F: FnOnce(&mut T)>(&mut self, initializer: F) {
-        let bl = self.0;
-        let s = bl + size_of::<T>();
-        if s <= L {
+    pub fn append_and_init_struct<T: RawObject, R, F: FnOnce(&mut T) -> R>(&mut self, initializer: F) -> std::io::Result<R> {
+        let ptr = self.0;
+        let end = ptr + size_of::<T>();
+        if end <= L {
+            self.0 = end;
             unsafe {
-                self.0 = s;
-                initializer(&mut *self.1.as_mut_ptr().cast::<u8>().offset(bl as isize).cast::<T>());
+                Ok(initializer(&mut *self.1.as_mut_ptr().cast::<u8>().offset(ptr as isize).cast::<T>()))
             }
         } else {
-            self.0 = bl | FAULT_BIT;
+            std::io::Result::Err(std::io::Error::new(std::io::ErrorKind::UnexpectedEof, "overflow"))
         }
     }
 
     /// Append and initialize a byte array with a fixed size set at compile time.
-    ///
     /// This is more efficient than setting a size at runtime as it may allow the compiler to
-    /// skip some bounds checking.
-    ///
-    /// If an overflow occurs the overflow fault bit is set internally (see check_overflow())
-    /// and the supplied function will never be called.
+    /// skip some bounds checking. Any bytes not initialized will be zero.
     #[inline(always)]
-    pub fn append_and_init_bytes_fixed<F: FnOnce(&mut [u8; N]), const N: usize>(&mut self, initializer: F) {
-        let bl = self.0;
-        let s = bl + N;
-        if s <= L {
+    pub fn append_and_init_bytes_fixed<R, F: FnOnce(&mut [u8; N]) -> R, const N: usize>(&mut self, initializer: F) -> std::io::Result<R> {
+        let ptr = self.0;
+        let end = ptr + N;
+        if end <= L {
+            self.0 = end;
             unsafe {
-                let ptr = self.1.as_mut_ptr().cast::<u8>().offset(bl as isize);
-                self.0 = s;
-                initializer(&mut *ptr.cast::<[u8; N]>());
+                Ok(initializer(&mut *self.1.as_mut_ptr().cast::<u8>().offset(ptr as isize).cast::<[u8; N]>()))
             }
         } else {
-            self.0 = bl | FAULT_BIT;
+            std::io::Result::Err(std::io::Error::new(std::io::ErrorKind::UnexpectedEof, "overflow"))
         }
     }
 
     /// Append and initialize a slice with a size that is set at runtime.
-    ///
-    /// If an overflow occurs the overflow fault bit is set internally (see check_overflow())
-    /// and the supplied function will never be called.
+    /// Any bytes not initialized will be zero.
     #[inline(always)]
-    pub fn append_and_init_bytes<F: FnOnce(&mut [u8])>(&mut self, l: usize, initializer: F) {
-        let bl = self.0;
-        let s = bl + l;
-        if s <= L {
-            self.0 = s;
-            initializer(&mut self.1[bl..s]);
+    pub fn append_and_init_bytes<R, F: FnOnce(&mut [u8]) -> R>(&mut self, l: usize, initializer: F) -> std::io::Result<R> {
+        let ptr = self.0;
+        let end = ptr + l;
+        if end <= L {
+            self.0 = end;
+            Ok(initializer(&mut self.1[ptr..end]))
         } else {
-            self.0 = bl | FAULT_BIT;
+            std::io::Result::Err(std::io::Error::new(std::io::ErrorKind::UnexpectedEof, "overflow"))
         }
     }
 
-    pub fn read_payload(&self) -> Reader<H, L> {
-        Reader {
-            buffer: self,
-            ptr: size_of::<H>(),
+    /// Append a dynamic byte slice (copy into buffer).
+    /// Use append_and_init_ functions if possible as these avoid extra copies.
+    #[inline(always)]
+    fn append_bytes(&mut self, buf: &[u8]) -> std::io::Result<()> {
+        let ptr = self.0;
+        let end = ptr + buf.len();
+        if end <= L {
+            self.0 = end;
+            self.1[ptr..end].copy_from_slice(buf);
+            Ok(())
+        } else {
+            std::io::Result::Err(std::io::Error::new(std::io::ErrorKind::UnexpectedEof, "overflow"))
         }
     }
-}
 
-pub struct Reader<'a, H: RawObject, const L: usize> {
-    ptr: usize,
-    buffer: &'a Buffer<H, L>,
-}
+    /// Append a fixed length byte array (copy into buffer).
+    /// Use append_and_init_ functions if possible as these avoid extra copies.
+    #[inline(always)]
+    fn append_bytes_fixed<const S: usize>(&mut self, buf: &[u8; S]) -> std::io::Result<()> {
+        let ptr = self.0;
+        let end = ptr + S;
+        if end <= L {
+            self.0 = end;
+            self.1[ptr..end].copy_from_slice(buf);
+            Ok(())
+        } else {
+            std::io::Result::Err(std::io::Error::new(std::io::ErrorKind::UnexpectedEof, "overflow"))
+        }
+    }
 
-impl<'a, H: RawObject, const L: usize> Reader<'a, H, L> {
-    pub fn read_struct<T: RawObject, R, F: FnOnce(&T, &mut Self) -> bool>(&mut self, visitor: F) -> bool {
-        let rl = self.ptr;
-        let s = rl + size_of::<T>();
-        if s <= L {
+    /// Append a byte
+    #[inline(always)]
+    fn append_u8(&mut self, i: u8) -> std::io::Result<()> {
+        let ptr = self.0;
+        if ptr < L {
+            self.0 = ptr + 1;
+            self.1[ptr] = i;
+            Ok(())
+        } else {
+            std::io::Result::Err(std::io::Error::new(std::io::ErrorKind::UnexpectedEof, "overflow"))
+        }
+    }
+
+    /// Append a 16-bit integer (in big-endian form)
+    #[inline(always)]
+    fn append_u16(&mut self, i: u16) -> std::io::Result<()> {
+        let ptr = self.0;
+        let end = ptr + 2;
+        if end <= L {
+            self.0 = end;
+            crate::util::integer_store_be_u16(i, &mut self.1[ptr..end]);
+            Ok(())
+        } else {
+            std::io::Result::Err(std::io::Error::new(std::io::ErrorKind::UnexpectedEof, "overflow"))
+        }
+    }
+
+    /// Append a 32-bit integer (in big-endian form)
+    #[inline(always)]
+    fn append_u32(&mut self, i: u32) -> std::io::Result<()> {
+        let ptr = self.0;
+        let end = ptr + 4;
+        if end <= L {
+            self.0 = end;
+            crate::util::integer_store_be_u32(i, &mut self.1[ptr..end]);
+            Ok(())
+        } else {
+            std::io::Result::Err(std::io::Error::new(std::io::ErrorKind::UnexpectedEof, "overflow"))
+        }
+    }
+
+    /// Append a 64-bit integer (in big-endian form)
+    #[inline(always)]
+    fn append_u64(&mut self, i: u64) -> std::io::Result<()> {
+        let ptr = self.0;
+        let end = ptr + 8;
+        if end <= L {
+            self.0 = end;
+            crate::util::integer_store_be_u64(i, &mut self.1[ptr..end]);
+            Ok(())
+        } else {
+            std::io::Result::Err(std::io::Error::new(std::io::ErrorKind::UnexpectedEof, "overflow"))
+        }
+    }
+
+    /// Get a structure at a given position in the buffer and advance the cursor.
+    #[inline(always)]
+    pub fn get_struct<T: RawObject>(&self, cursor: &mut usize) -> std::io::Result<&T> {
+        let ptr = *cursor;
+        let end = ptr + size_of::<T>();
+        if end <= self.0 {
+            *cursor = end;
             unsafe {
-                self.ptr = s;
-                visitor(&*self.buffer.1.as_ptr().cast::<u8>().offset(rl as isize).cast::<T>(), self)
+                Ok(&*self.1.as_ptr().cast::<u8>().offset(ptr as isize).cast::<T>())
             }
         } else {
-            false
+            std::io::Result::Err(std::io::Error::new(std::io::ErrorKind::UnexpectedEof, "overflow"))
         }
     }
+
+    /// Get a fixed length byte array and advance the cursor.
+    /// This is slightly more efficient than reading a runtime sized byte slice.
+    #[inline(always)]
+    pub fn get_bytes_fixed<const S: usize>(&self, cursor: &mut usize) -> std::io::Result<&[u8; S]> {
+        let ptr = *cursor;
+        let end = ptr + S;
+        if end <= self.0 {
+            *cursor = end;
+            unsafe {
+                Ok(&*self.1.as_ptr().cast::<u8>().offset(ptr as isize).cast::<[u8; S]>())
+            }
+        } else {
+            std::io::Result::Err(std::io::Error::new(std::io::ErrorKind::UnexpectedEof, "overflow"))
+        }
+    }
+
+    /// Get a runtime specified length byte slice and advance the cursor.
+    #[inline(always)]
+    pub fn get_bytes(&self, l: usize, cursor: &mut usize) -> std::io::Result<&[u8]> {
+        let ptr = *cursor;
+        let end = ptr + l;
+        if end <= self.0 {
+            *cursor = end;
+            Ok(&self.1[ptr..end])
+        } else {
+            std::io::Result::Err(std::io::Error::new(std::io::ErrorKind::UnexpectedEof, "overflow"))
+        }
+    }
+
+    /// Get the next u8 and advance the cursor.
+    #[inline(always)]
+    pub fn get_u8(&self, cursor: &mut usize) -> std::io::Result<u8> {
+        let ptr = *cursor;
+        if ptr < self.0 {
+            *cursor = ptr + 1;
+            Ok(self.1[ptr])
+        } else {
+            std::io::Result::Err(std::io::Error::new(std::io::ErrorKind::UnexpectedEof, "overflow"))
+        }
+    }
+
+    /// Get the next u16 and advance the cursor.
+    #[inline(always)]
+    pub fn get_u16(&self, cursor: &mut usize) -> std::io::Result<u16> {
+        let ptr = *cursor;
+        let end = ptr + 2;
+        if end <= self.0 {
+            *cursor = end;
+            Ok(crate::util::integer_load_be_u16(&self.1[ptr..end]))
+        } else {
+            std::io::Result::Err(std::io::Error::new(std::io::ErrorKind::UnexpectedEof, "overflow"))
+        }
+    }
+
+    /// Get the next u32 and advance the cursor.
+    #[inline(always)]
+    pub fn get_u32(&self, cursor: &mut usize) -> std::io::Result<u32> {
+        let ptr = *cursor;
+        let end = ptr + 4;
+        if end <= self.0 {
+            *cursor = end;
+            Ok(crate::util::integer_load_be_u32(&self.1[ptr..end]))
+        } else {
+            std::io::Result::Err(std::io::Error::new(std::io::ErrorKind::UnexpectedEof, "overflow"))
+        }
+    }
+
+    /// Get the next u64 and advance the cursor.
+    #[inline(always)]
+    pub fn get_u64(&self, cursor: &mut usize) -> std::io::Result<u64> {
+        let ptr = *cursor;
+        let end = ptr + 8;
+        if end <= self.0 {
+            *cursor = end;
+            Ok(crate::util::integer_load_be_u64(&self.1[ptr..end]))
+        } else {
+            std::io::Result::Err(std::io::Error::new(std::io::ErrorKind::UnexpectedEof, "overflow"))
+        }
+    }
+}
+
+impl<H: RawObject, const L: usize> Write for Buffer<H, L> {
+    #[inline(always)]
+    fn write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
+        let ptr = self.0;
+        let end = ptr + buf.len();
+        if end <= L {
+            self.0 = end;
+            self.1[ptr..end].copy_from_slice(buf);
+            Ok(buf.len())
+        } else {
+            std::io::Result::Err(std::io::Error::new(std::io::ErrorKind::UnexpectedEof, "overflow"))
+        }
+    }
+
+    #[inline(always)]
+    fn flush(&mut self) -> std::io::Result<()> {
+        Ok(())
+    }
 }
 
 #[cfg(test)]
diff --git a/network-hypervisor/src/vl1/identity.rs b/network-hypervisor/src/vl1/identity.rs
new file mode 100644
index 000000000..c23e189d0
--- /dev/null
+++ b/network-hypervisor/src/vl1/identity.rs
@@ -0,0 +1,133 @@
+use std::io::Write;
+
+use crate::crypto::c25519::{C25519_PUBLIC_KEY_SIZE, ED25519_PUBLIC_KEY_SIZE, C25519_SECRET_KEY_SIZE, ED25519_SECRET_KEY_SIZE, C25519KeyPair, Ed25519KeyPair};
+use crate::crypto::p521::{P521KeyPair, P521PublicKey, P521_ECDSA_SIGNATURE_SIZE, P521_PUBLIC_KEY_SIZE, P521_SECRET_KEY_SIZE};
+use crate::vl1::Address;
+use crate::crypto::hash::SHA384;
+
+#[derive(Copy, Clone)]
+#[repr(u8)]
+pub enum Type {
+    /// Curve25519 / Ed25519 identity (type 0)
+    C25519 = 0,
+    /// NIST P-521 ECDH / ECDSA identity (also has c25519/ed25519 keys for backward compability) (type 1)
+    P521 = 1
+}
+
+struct IdentitySecrets {
+    c25519: C25519KeyPair,
+    ed25519: Ed25519KeyPair,
+    p521: Option<(P521KeyPair, P521KeyPair)>, // ecdh key, ecdsa key
+}
+
+pub struct Identity {
+    address: Address,
+    c25519_public: [u8; C25519_PUBLIC_KEY_SIZE],
+    ed25519_public: [u8; ED25519_PUBLIC_KEY_SIZE],
+    p521_public: Option<(P521PublicKey, P521PublicKey, [u8; P521_ECDSA_SIGNATURE_SIZE])>, // ecdh key, ecdsa key, ecdsa signature of all keys
+    secrets: Option<IdentitySecrets>,
+}
+
+impl Identity {
+    fn generate_c25519() {
+    }
+
+    fn generate_p521() {
+    }
+
+    /// Generate a new identity.
+    /// This is time consuming due to the one-time anti-collision proof of work required
+    /// to generate an address corresponding with a set of identity keys. V0 identities
+    /// take tens to hundreds of milliseconds on a typical 2020 system, while V1 identites
+    /// take about 500ms. Generation can take a lot longer on low power devices, but only
+    /// has to be done once.
+    pub fn generate(id_type: Type) {
+        match id_type {
+            Type::C25519 => Self::generate_c25519(),
+            Type::P521 => Self::generate_p521()
+        }
+    }
+
+    /// Execute ECDH key agreement and return SHA384(shared secret).
+    /// If both keys are type 1, key agreement is done with NIST P-521. Otherwise it's done
+    /// with Curve25519. None is returned if there is an error such as this identity missing
+    /// its secrets or a key being invalid.
+    pub fn agree(&self, other_identity: &Identity) -> Option<[u8; 48]> {
+        self.secrets.as_ref().map_or(None, |secrets| {
+            secrets.p521.as_ref().map_or_else(|| {
+                Some(SHA384::hash(&secrets.c25519.agree(&other_identity.c25519_public)))
+            }, |p521_secret| {
+                other_identity.p521_public.as_ref().map_or_else(|| {
+                    Some(SHA384::hash(&secrets.c25519.agree(&other_identity.c25519_public)))
+                }, |other_p521_public| {
+                    p521_secret.0.agree(&other_p521_public.0).map_or(None, |secret| Some(SHA384::hash(&secret)))
+                })
+            })
+        })
+    }
+
+    /// Sign this message with this identity.
+    /// Signature is performed using ed25519 EDDSA or NIST P-521 ECDSA depending on the identity
+    /// type. None is returned if this identity lacks secret keys or another error occurs.
+    pub fn sign(&self, msg: &[u8]) -> Option<Vec<u8>> {
+        self.secrets.as_ref().map_or(None, |secrets| {
+            secrets.p521.as_ref().map_or_else(|| {
+                Some(secrets.ed25519.sign(msg).to_vec())
+            }, |p521_secret| {
+                p521_secret.1.sign(msg).map_or(None, |sig| Some(sig.to_vec()))
+            })
+        })
+    }
+
+    /// Get this identity's type.
+    #[inline(always)]
+    pub fn id_type(&self) -> Type {
+        if self.p521_public.is_some() {
+            Type::P521
+        } else {
+            Type::C25519
+        }
+    }
+
+    /// Returns true if this identity also holds its secret keys.
+    #[inline(always)]
+    pub fn has_secrets(&self) -> bool {
+        self.secrets.is_some()
+    }
+
+    /// Get this identity in string format, including its secret keys.
+    pub fn to_secret_string(&self) -> String {
+        self.secrets.as_ref().map_or_else(|| {
+            self.to_string()
+        }, |secrets| {
+            secrets.p521.as_ref().map_or_else(|| {
+                format!("{}:{}{}", self.to_string(), crate::util::hex::to_string(&secrets.c25519.secret_bytes()), crate::util::hex::to_string(&secrets.ed25519.secret_bytes()))
+            }, |p521_secret| {
+                let mut secret_key_blob: Vec<u8> = Vec::new();
+                secret_key_blob.reserve(C25519_SECRET_KEY_SIZE + ED25519_SECRET_KEY_SIZE + P521_SECRET_KEY_SIZE + P521_SECRET_KEY_SIZE);
+                let _ = secret_key_blob.write_all(&secrets.c25519.secret_bytes());
+                let _ = secret_key_blob.write_all(&secrets.ed25519.secret_bytes());
+                let _ = secret_key_blob.write_all(p521_secret.0.secret_key_bytes());
+                let _ = secret_key_blob.write_all(p521_secret.1.secret_key_bytes());
+                format!("{}:{}", self.to_string(), base64::encode_config(secret_key_blob.as_slice(), base64::URL_SAFE_NO_PAD))
+            })
+        })
+    }
+}
+
+impl ToString for Identity {
+    fn to_string(&self) -> String {
+        self.p521_public.as_ref().map_or_else(|| {
+            format!("{:0>10x}:0:{}{}", self.address.to_u64(), crate::util::hex::to_string(&self.c25519_public), crate::util::hex::to_string(&self.ed25519_public))
+        }, |p521_public| {
+            let mut public_key_blob: Vec<u8> = Vec::new();
+            public_key_blob.reserve(C25519_PUBLIC_KEY_SIZE + ED25519_PUBLIC_KEY_SIZE + P521_PUBLIC_KEY_SIZE + P521_PUBLIC_KEY_SIZE + P521_ECDSA_SIGNATURE_SIZE);
+            let _ = public_key_blob.write_all(&self.c25519_public);
+            let _ = public_key_blob.write_all(&self.ed25519_public);
+            let _ = public_key_blob.write_all(p521_public.0.public_key_bytes());
+            let _ = public_key_blob.write_all(p521_public.1.public_key_bytes());
+            let _ = public_key_blob.write_all(&p521_public.2);
+            format!("{:0>10x}:1:{}", self.address.to_u64(), base64::encode_config(public_key_blob.as_slice(), base64::URL_SAFE_NO_PAD))
+        })
+    }
+}
diff --git a/network-hypervisor/src/vl1/mod.rs b/network-hypervisor/src/vl1/mod.rs
index 7ae531cc2..4ca557fe1 100644
--- a/network-hypervisor/src/vl1/mod.rs
+++ b/network-hypervisor/src/vl1/mod.rs
@@ -1,8 +1,8 @@
 pub mod protocol;
 pub mod packet;
 pub mod buffer;
+pub mod node;
 mod address;
-mod mac;
+mod identity;
 
 pub use address::Address;
-pub use mac::MAC;
diff --git a/network-hypervisor/src/vl1/node.rs b/network-hypervisor/src/vl1/node.rs
new file mode 100644
index 000000000..b404175b9
--- /dev/null
+++ b/network-hypervisor/src/vl1/node.rs
@@ -0,0 +1,59 @@
+//use crate::vl1::Address;
+
+/*
+/// Handler for events generated by the node that pertain to VL1.
+pub trait VL1NodeEventHandler: Sync + Send {
+    /// Called when a core ZeroTier event occurs.
+    fn event(&self, event: Event, event_data: &[u8]);
+
+    /// Called to store an object into the object store.
+    fn state_put(&self, obj_type: StateObjectType, obj_id: &[u64], obj_data: &[u8]) -> std::io::Result<()>;
+
+    /// Called to retrieve an object from the object store.
+    fn state_get(&self, obj_type: StateObjectType, obj_id: &[u64]) -> std::io::Result<Vec<u8>>;
+
+    /// Called to send a packet over the physical network (virtual -> physical).
+    fn wire_packet_send(&self, local_socket: i64, sock_addr: &InetAddress, data: &[u8], packet_ttl: u32) -> i32;
+
+    /// Called to check and see if a physical address should be used for ZeroTier traffic.
+    fn path_check(&self, address: Address, id: &Identity, local_socket: i64, sock_addr: &InetAddress) -> bool;
+
+    /// Called to look up a path to a known node, allowing out of band lookup methods for physical paths to nodes.
+    fn path_lookup(&self, address: Address, id: &Identity, desired_family: InetAddressFamily) -> Option<InetAddress>;
+}
+
+pub struct Node<H: VL1NodeEventHandler> {
+    handler: H,
+}
+
+impl<H: VL1NodeEventHandler> Node<H> {
+    pub fn new(handler: H) -> Self {
+        Self {
+            handler,
+        }
+    }
+
+    pub fn handler(&self) -> &H {
+        &self.handler
+    }
+
+    pub fn handler_mut(&mut self) -> &mut H {
+        &mut self.handler
+    }
+
+    /// Perform periodic background tasks.
+    /// The first call should happen no more than NODE_BACKGROUND_TASKS_MAX_INTERVAL milliseconds
+    /// since the node was created, and after this runs it returns the amount of time the caller
+    /// should wait before calling it again.
+    #[inline(always)]
+    pub fn process_background_tasks(&self, clock: i64, ticks: i64) -> i64 {
+        0
+    }
+
+    /// Get the address of this node.
+    #[inline(always)]
+    pub fn address(&self) -> Address {
+        Address::default()
+    }
+}
+*/
\ No newline at end of file
diff --git a/network-hypervisor/src/vl1/packet.rs b/network-hypervisor/src/vl1/packet.rs
index a5923ec13..5746d189f 100644
--- a/network-hypervisor/src/vl1/packet.rs
+++ b/network-hypervisor/src/vl1/packet.rs
@@ -51,7 +51,6 @@ impl Header {
     }
 }
 
-/// Packet is a Buffer with the packet Header and the packet max payload size.
 pub type Packet = Buffer<Header, { crate::vl1::protocol::PACKET_SIZE_MAX }>;
 
 #[derive(Clone)]
@@ -83,6 +82,8 @@ impl FragmentHeader {
     }
 }
 
+type Fragment = Buffer<FragmentHeader, { crate::vl1::protocol::PACKET_SIZE_MAX }>;
+
 #[cfg(test)]
 mod tests {
     use std::mem::size_of;
diff --git a/network-hypervisor/src/vl1/mac.rs b/network-hypervisor/src/vl2/mac.rs
similarity index 100%
rename from network-hypervisor/src/vl1/mac.rs
rename to network-hypervisor/src/vl2/mac.rs
diff --git a/network-hypervisor/src/vl2/mod.rs b/network-hypervisor/src/vl2/mod.rs
new file mode 100644
index 000000000..9ac77518a
--- /dev/null
+++ b/network-hypervisor/src/vl2/mod.rs
@@ -0,0 +1,3 @@
+mod mac;
+
+pub use mac::MAC;
diff --git a/vli/Cargo.lock b/vli/Cargo.lock
new file mode 100644
index 000000000..a38e846a1
--- /dev/null
+++ b/vli/Cargo.lock
@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "vli"
+version = "0.1.0"
diff --git a/vli/Cargo.toml b/vli/Cargo.toml
new file mode 100644
index 000000000..021a7a1c9
--- /dev/null
+++ b/vli/Cargo.toml
@@ -0,0 +1,11 @@
+[package]
+name = "vli"
+version = "0.1.0"
+edition = "2018"
+
+[profile.test]
+opt-level = 3
+lto = true
+codegen-units = 1
+
+[dependencies]
diff --git a/vli/src/lib.rs b/vli/src/lib.rs
new file mode 100644
index 000000000..d4ef3302d
--- /dev/null
+++ b/vli/src/lib.rs
@@ -0,0 +1,411 @@
+use std::cmp::Ordering;
+use std::ops::{Add, AddAssign, Sub, Shl, Shr, SubAssign, ShlAssign, ShrAssign};
+use std::io::Write;
+use std::mem::MaybeUninit;
+
+const HEX_CHARS: [char; 16] = ['0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'];
+
+/// Arbitrarily large unsigned integer supporting basic and modular arithmetic.
+///
+/// LIMBS is the number of 64-bit "limbs" (large digits) in this VLI. The number of bits is
+/// 64 times LIMBS, so for 1024 bits use 16 LIMBS. We don't have a generic BITS instead
+/// because of current limitations on Rust const generics and what can be done with them.
+/// This also means the size of a VLI must be a multiple of 64 bits. Note that the actual
+/// integer in it need not be exactly that length, just the capacity of the container.
+#[derive(Clone, PartialEq, Eq)]
+pub struct VLI<const LIMBS: usize> {
+    n: [u64; LIMBS]
+}
+
+impl<const LIMBS: usize> Default for VLI<LIMBS> {
+    #[inline(always)]
+    fn default() -> Self {
+        Self { n: [0_u64; LIMBS ]}
+    }
+}
+
+impl<const LIMBS: usize> VLI<LIMBS> {
+    /// Create a new zero VLI.
+    #[inline(always)]
+    pub fn new() -> Self {
+        Self { n: [0_u64; LIMBS ]}
+    }
+
+    /// Set to zero.
+    #[inline(always)]
+    pub fn zero(&mut self) {
+        self.n.fill(0)
+    }
+
+    /// Test whether bit is set (numbered from right to left).
+    /// This will panic if bit is out of range.
+    #[inline(always)]
+    pub fn test_bit(&self, bit: usize) -> bool {
+        (self.n[bit >> 6] & (1_u64 << (bit & 63))) != 0
+    }
+
+    /// Count the number of non-zero bits.
+    pub fn count_ones(&self) -> u32 {
+        let mut ones = 0_u32;
+        for n in self.n {
+            ones += n.count_ones();
+        }
+        ones
+    }
+
+    /// Count the number of zero bits.
+    #[inline(always)]
+    pub fn count_zeros(&self) -> u32 {
+        let mut zeros = 0_u32;
+        for n in self.n {
+            zeros += n.count_zeros();
+        }
+        zeros
+    }
+
+    /// Returns true if this integer is zero.
+    #[inline(always)]
+    pub fn is_zero(&self) -> bool {
+        for n in self.n {
+            if n != 0 {
+                return false;
+            }
+        }
+        true
+    }
+
+    /// Returns true if this is an odd number.
+    #[inline(always)]
+    pub fn is_odd(&self) -> bool {
+        (self.n[0] & 1) != 0
+    }
+
+    /// Returns true if this is an even number.
+    #[inline(always)]
+    pub fn is_even(&self) -> bool {
+        (self.n[0] & 1) == 0
+    }
+
+    /// Add to this integer and return any overflow carry bits.
+    pub fn add_assign_carry(&mut self, rhs: &Self) -> u64 {
+        let mut carry = 0_u64;
+        for i in 0..LIMBS {
+            let left_ptr = unsafe { self.n.get_unchecked_mut(i) };
+            let left = *left_ptr;
+            let sum = left + *unsafe { rhs.n.get_unchecked(i) } + carry;
+            carry = (sum < left) as u64;
+            *left_ptr = sum;
+        }
+        carry
+    }
+
+    /// Multiply two inputs half the size of this integer to yield a full size result in this integer..
+    /// The multiplicand sizes MULT_LIMBS must be one half the LIMBS size of this integer.
+    /// This is checked with an assertion. This isn't computed with the type system due
+    /// to current limitations in const generics.
+    pub fn mul_extend_assign<const MULT_LIMBS: usize>(&mut self, lhs: &VLI<{ MULT_LIMBS }>, rhs: &VLI<{ MULT_LIMBS }>) {
+        assert_eq!(MULT_LIMBS, LIMBS / 2);
+        let mut r01 = 0_u128;
+        let mut r2 = 0_u64;
+        let mut k = 0_usize;
+        while k < MULT_LIMBS {
+            for i in 0..k {
+                let l_product = (*unsafe { lhs.get_unchecked(i) } as u128) * (*unsafe { rhs.get_unchecked(k - i) } as u128);
+                r01 += l_product;
+                r2 += (r01 < l_product) as u64;
+            }
+            *unsafe { self.n.get_unchecked_mut(k) } = r01 as u64;
+            r01 += (r01 >> 64) | ((r2 as u128) << 64);
+            r2 = 0;
+            k += 1;
+        }
+        while k < (LIMBS - 1) {
+            let mut i = (k + 1) - MULT_LIMBS;
+            while i < k && i < MULT_LIMBS {
+                let l_product = (*unsafe { lhs.get_unchecked(i) } as u128) * (*unsafe { rhs.get_unchecked(k - i) } as u128);
+                r01 += l_product;
+                r2 += (r01 < l_product) as u64;
+                i += 1;
+            }
+            *unsafe { self.n.get_unchecked_mut(k) } = r01 as u64;
+            r01 += (r01 >> 64) | ((r2 as u128) << 64);
+            r2 = 0;
+            k += 1;
+        }
+        *unsafe { self.n.get_unchecked_mut(LIMBS - 1) } = r01 as u64;
+    }
+
+    /// Get this integer as a big-endian byte array.
+    /// If skip_leading_zeroes is true the returned byte vector will be the minimum size
+    /// needed to hold the integer, or empty if it is zero. Otherwise it will always be
+    /// LIMBS * 8 bytes in length.
+    pub fn to_vec(&self, skip_leading_zeroes: bool) -> Vec<u8> {
+        let mut bytes: Vec<u8> = Vec::new();
+        bytes.reserve(LIMBS * 8);
+
+        let mut i = LIMBS as isize - 1;
+        if skip_leading_zeroes {
+            while i >= 0 {
+                let x: u64 = *unsafe { self.n.get_unchecked(i as usize) };
+                if x != 0 {
+                    let x = x.to_be_bytes();
+                    for j in 0..8 {
+                        if x[j] != 0 {
+                            let _ = bytes.write_all(&x[j..8]);
+                            break;
+                        }
+                    }
+                    break;
+                }
+                i -= 1;
+            }
+        }
+        while i >= 0 {
+            let _ = bytes.write_all(&(unsafe { self.n.get_unchecked(i as usize) }.to_be_bytes()));
+            i -= 1;
+        }
+
+        bytes
+    }
+
+    /// Get this integer as a hex string.
+    /// If skip_leading_zeroes is true, the returned string will not be left padded with zeroes
+    /// to the size it would be if the integer's bits were saturated.
+    pub fn to_hex_string(&self, skip_leading_zeroes: bool) -> String {
+        let mut s = String::new();
+        s.reserve(LIMBS * 16);
+
+        let mut i = LIMBS as isize - 1;
+        if skip_leading_zeroes {
+            while i >= 0 {
+                let mut x: u64 = *unsafe { self.n.get_unchecked(i as usize) };
+                if x != 0 {
+                    let mut j = 0;
+                    while j < 16 {
+                        if (x >> 60) != 0 {
+                            break;
+                        }
+                        x <<= 4;
+                        j += 1;
+                    }
+                    while j < 16 {
+                        s.push(HEX_CHARS[(x >> 60) as usize]);
+                        x <<= 4;
+                        j += 1;
+                    }
+                    break;
+                }
+                i -= 1;
+            }
+        }
+        while i >= 0 {
+            let mut x: u64 = *unsafe { self.n.get_unchecked(i as usize) };
+            for _ in 0..16 {
+                s.push(HEX_CHARS[(x >> 60) as usize]);
+                x <<= 4;
+            }
+            i -= 1;
+        }
+
+        if s.is_empty() {
+            s.push('0');
+        }
+
+        s
+    }
+}
+
+impl<const LIMBS: usize> Add<&Self> for VLI<LIMBS> {
+    type Output = Self;
+
+    #[inline(always)]
+    fn add(mut self, rhs: &Self) -> Self::Output {
+        self.add_assign(rhs);
+        self
+    }
+}
+
+impl<const LIMBS: usize> AddAssign<&Self> for VLI<LIMBS> {
+    fn add_assign(&mut self, rhs: &Self) {
+        let mut carry = 0_u64;
+        for i in 0..LIMBS {
+            let left_ptr = unsafe { self.n.get_unchecked_mut(i) };
+            let left = *left_ptr;
+            let sum = left + *unsafe { rhs.n.get_unchecked(i) } + carry;
+            carry = (sum < left) as u64;
+            *left_ptr = sum;
+        }
+    }
+}
+
+impl<const LIMBS: usize> Sub<&Self> for VLI<LIMBS> {
+    type Output = Self;
+
+    #[inline(always)]
+    fn sub(mut self, rhs: &Self) -> Self::Output {
+        self.sub_assign(rhs);
+        self
+    }
+}
+
+impl<const LIMBS: usize> SubAssign<&Self> for VLI<LIMBS> {
+    fn sub_assign(&mut self, rhs: &Self) {
+        let mut borrow = 0_u64;
+        for i in 0..LIMBS {
+            let left_ptr = unsafe { self.n.get_unchecked_mut(i) };
+            let left = *left_ptr;
+            let diff = left - *unsafe { rhs.n.get_unchecked(i) } - borrow;
+            borrow = (diff > left) as u64;
+            *left_ptr = diff;
+        }
+    }
+}
+
+impl<const LIMBS: usize> Shl<usize> for VLI<LIMBS> {
+    type Output = Self;
+
+    #[inline(always)]
+    fn shl(mut self, rhs: usize) -> Self::Output {
+        self.shl_assign(rhs);
+        self
+    }
+}
+
+impl<const LIMBS: usize> ShlAssign<usize> for VLI<LIMBS> {
+    fn shl_assign(&mut self, rhs: usize) {
+        if rhs != 0 {
+            if rhs < 64 {
+                let mut carry = 0_u64;
+                for i in 0..LIMBS {
+                    let x_ptr = unsafe { self.n.get_unchecked_mut(i) };
+                    let x = *x_ptr;
+                    *x_ptr = (x << rhs) | carry;
+                    carry = x >> (64 - rhs);
+                }
+            } else {
+                self.zero();
+            }
+        }
+    }
+}
+
+impl<const LIMBS: usize> Shr<usize> for VLI<LIMBS> {
+    type Output = Self;
+
+    #[inline(always)]
+    fn shr(mut self, rhs: usize) -> Self::Output {
+        self.shr_assign(rhs);
+        self
+    }
+}
+
+impl<const LIMBS: usize> ShrAssign<usize> for VLI<LIMBS> {
+    fn shr_assign(&mut self, rhs: usize) {
+        if rhs != 0 {
+            if rhs < 64 {
+                let mut carry = 0_u64;
+                let mut i = LIMBS as isize - 1;
+                while i >= 0 {
+                    let x_ptr = unsafe { self.n.get_unchecked_mut(i as usize) };
+                    let x = *x_ptr;
+                    *x_ptr = (x >> rhs) | carry;
+                    carry = x << (64 - rhs);
+                    i -= 1;
+                }
+            } else {
+                self.zero();
+            }
+        }
+    }
+}
+
+impl<const LIMBS: usize> PartialOrd for VLI<LIMBS> {
+    #[inline(always)]
+    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+        Some(self.cmp(other))
+    }
+
+    fn lt(&self, other: &Self) -> bool {
+        let mut i = LIMBS as isize - 1;
+        while i >= 0 {
+            let a = *unsafe { self.n.get_unchecked(i as usize) };
+            let b = *unsafe { other.n.get_unchecked(i as usize) };
+            if a > b {
+                return false;
+            } else if a < b {
+                return true;
+            }
+            i -= 1;
+        }
+        false
+    }
+
+    fn le(&self, other: &Self) -> bool {
+        let mut i = LIMBS as isize - 1;
+        while i >= 0 {
+            let a = *unsafe { self.n.get_unchecked(i as usize) };
+            let b = *unsafe { other.n.get_unchecked(i as usize) };
+            if a > b {
+                return false;
+            } else if a < b {
+                return true;
+            }
+            i -= 1;
+        }
+        true
+    }
+
+    fn gt(&self, other: &Self) -> bool {
+        let mut i = LIMBS as isize - 1;
+        while i >= 0 {
+            let a = *unsafe { self.n.get_unchecked(i as usize) };
+            let b = *unsafe { other.n.get_unchecked(i as usize) };
+            if a > b {
+                return true;
+            } else if a < b {
+                return false;
+            }
+            i -= 1;
+        }
+        false
+    }
+
+    fn ge(&self, other: &Self) -> bool {
+        let mut i = LIMBS as isize - 1;
+        while i >= 0 {
+            let a = *unsafe { self.n.get_unchecked(i as usize) };
+            let b = *unsafe { other.n.get_unchecked(i as usize) };
+            if a > b {
+                return true;
+            } else if a < b {
+                return false;
+            }
+            i -= 1;
+        }
+        true
+    }
+}
+
+impl<const LIMBS: usize> Ord for VLI<LIMBS> {
+    fn cmp(&self, other: &Self) -> Ordering {
+        let mut i = LIMBS as isize - 1;
+        while i >= 0 {
+            let a = *unsafe { self.n.get_unchecked(i as usize) };
+            let b = *unsafe { other.n.get_unchecked(i as usize) };
+            if a > b {
+                return Ordering::Greater;
+            } else if a < b {
+                return Ordering::Less;
+            }
+            i -= 1;
+        }
+        Ordering::Equal
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn arithmetic() {
+    }
+}