diff --git a/bitpacker/src/bitpacker.rs b/bitpacker/src/bitpacker.rs
index d079c29de..e022e33e9 100644
--- a/bitpacker/src/bitpacker.rs
+++ b/bitpacker/src/bitpacker.rs
@@ -103,28 +103,6 @@ impl BitUnpacker {
         let val_shifted = (val_unshifted_unmasked >> bit_shift) as u64;
         val_shifted & mask
     }
-
-    #[inline]
-    pub fn get_u32(&self, idx: u64, data: &[u8]) -> u32 {
-        if self.num_bits == 0 {
-            return 0u32;
-        }
-        let num_bits = self.num_bits;
-        let mask = self.mask as u32;
-        let addr_in_bits = idx * num_bits;
-        let addr = addr_in_bits >> 3;
-        let bit_shift = addr_in_bits & 7;
-        debug_assert!(
-            addr + 8 <= data.len() as u64,
-            "The fast field field should have been padded with 7 bytes."
-        );
-        let bytes: [u8; 4] = (&data[(addr as usize)..(addr as usize) + 4])
-            .try_into()
-            .unwrap();
-        let val_unshifted_unmasked: u32 = u32::from_le_bytes(bytes);
-        let val_shifted = (val_unshifted_unmasked >> bit_shift) as u32;
-        val_shifted & mask
-    }
 }
 
 #[cfg(test)]
diff --git a/fastfield_codecs/src/ip_codec.rs b/fastfield_codecs/src/ip_codec.rs
index 7d612710a..862230cdc 100644
--- a/fastfield_codecs/src/ip_codec.rs
+++ b/fastfield_codecs/src/ip_codec.rs
@@ -399,6 +399,10 @@ pub fn train(ip_addrs_sorted: &[u128]) -> IntervalCompressor {
 }
 
 impl IntervalCompressor {
+    /// Taking the vals as Vec may cost a lot of memory.
+    /// It is used to sort the vals.
+    ///
+    /// Less memory alternative: We could just store the index (u32), and use that as sorting.
     pub fn from_vals(mut vals: Vec<u128>) -> Self {
         vals.sort();
         train(&vals)
@@ -492,6 +496,10 @@ impl FastFieldCodecReaderU128 for IntervallDecompressor {
     fn null_value(&self) -> u128 {
         self.compact_space.null_value
     }
+
+    fn iter<'a>(&'a self, data: &'a [u8]) -> Box<dyn Iterator<Item = Option<u128>> + 'a> {
+        Box::new(self.iter(data))
+    }
 }
 
 impl IntervallDecompressor {
@@ -586,11 +594,16 @@ impl IntervallDecompressor {
     }
 
     #[inline]
-    pub fn iter<'a>(&'a self, data: &'a [u8]) -> impl Iterator<Item = u128> + 'a {
+    fn iter<'a>(&'a self, data: &'a [u8]) -> impl Iterator<Item = Option<u128>> + 'a {
         // TODO: Performance. It would be better to iterate on the ranges and check existence via
         // the bit_unpacker.
-        self.iter_compact(data)
-            .map(|compact| self.compact_to_ip_addr(compact))
+        self.iter_compact(data).map(|compact| {
+            if compact == self.null_compact_space {
+                None
+            } else {
+                Some(self.compact_to_ip_addr(compact))
+            }
+        })
     }
 
     pub fn get(&self, idx: u64, data: &[u8]) -> Option<u128> {
diff --git a/fastfield_codecs/src/lib.rs b/fastfield_codecs/src/lib.rs
index 5742e9285..78535e6f5 100644
--- a/fastfield_codecs/src/lib.rs
+++ b/fastfield_codecs/src/lib.rs
@@ -28,6 +28,11 @@ pub trait FastFieldCodecReaderU128: Sized {
     /// Get value for doc
     fn get(&self, doc: u64, data: &[u8]) -> Option<u128>;
 
+    /// Iterator
+    ///
+    /// Replace with opaque type after: https://github.com/rust-lang/rust/issues/63063
+    fn iter<'a>(&'a self, data: &'a [u8]) -> Box<dyn Iterator<Item = Option<u128>> + 'a>;
+
     /// Get docs for value range
     fn get_range(&self, range: RangeInclusive<u128>, data: &[u8]) -> Vec<usize>;
 
diff --git a/src/fastfield/fast_value.rs b/src/fastfield/fast_value.rs
new file mode 100644
index 000000000..980ba8b53
--- /dev/null
+++ b/src/fastfield/fast_value.rs
@@ -0,0 +1,235 @@
+use std::net::{IpAddr, Ipv6Addr};
+
+use crate::schema::{Cardinality, FieldType, Type};
+use crate::DateTime;
+pub fn ip_to_u128(ip_addr: IpAddr) -> u128 {
+    let ip_addr_v6: Ipv6Addr = match ip_addr {
+        IpAddr::V4(v4) => v4.to_ipv6_mapped(),
+        IpAddr::V6(v6) => v6,
+    };
+    u128::from_be_bytes(ip_addr_v6.octets())
+}
+
+/// Trait for large types that are allowed for fast fields: u128, IpAddr
+pub trait FastValueU128: Clone + Copy + Send + Sync + PartialOrd + 'static {
+    /// Converts a value from u128
+    ///
+    /// Internally all fast field values are encoded as u128.
+    /// **Note: To be used for converting encoded Term, Posting values.**
+    fn from_u128(val: u128) -> Self;
+
+    /// Converts a value to u128.
+    ///
+    /// Internally all fast field values are encoded as u128.
+    fn to_u128(&self) -> u128;
+
+    /// Cast value to `u128`.
+    /// The value is just reinterpreted in memory.
+    fn as_u128(&self) -> u128;
+
+    /// Returns the `schema::Type` for this FastValue.
+    fn to_type() -> Type;
+}
+
+impl FastValueU128 for u128 {
+    fn from_u128(val: u128) -> Self {
+        val
+    }
+
+    fn to_u128(&self) -> u128 {
+        *self
+    }
+
+    fn as_u128(&self) -> u128 {
+        *self
+    }
+
+    fn to_type() -> Type {
+        Type::U128
+    }
+}
+
+impl FastValueU128 for IpAddr {
+    fn from_u128(val: u128) -> Self {
+        IpAddr::from(val.to_le_bytes())
+    }
+
+    fn to_u128(&self) -> u128 {
+        ip_to_u128(*self)
+    }
+
+    fn as_u128(&self) -> u128 {
+        ip_to_u128(*self)
+    }
+
+    fn to_type() -> Type {
+        Type::Ip
+    }
+}
+
+/// Trait for types that are allowed for fast fields:
+/// (u64, i64 and f64, bool, DateTime).
+pub trait FastValue: Clone + Copy + Send + Sync + PartialOrd + 'static {
+    /// Converts a value from u64
+    ///
+    /// Internally all fast field values are encoded as u64.
+    /// **Note: To be used for converting encoded Term, Posting values.**
+    fn from_u64(val: u64) -> Self;
+
+    /// Converts a value to u64.
+    ///
+    /// Internally all fast field values are encoded as u64.
+    fn to_u64(&self) -> u64;
+
+    /// Returns the fast field cardinality that can be extracted from the given
+    /// `FieldType`.
+    ///
+    /// If the type is not a fast field, `None` is returned.
+    fn fast_field_cardinality(field_type: &FieldType) -> Option<Cardinality>;
+
+    /// Cast value to `u64`.
+    /// The value is just reinterpreted in memory.
+    fn as_u64(&self) -> u64;
+
+    /// Build a default value. This default value is never used, so the value does not
+    /// really matter.
+    fn make_zero() -> Self {
+        Self::from_u64(0i64.to_u64())
+    }
+
+    /// Returns the `schema::Type` for this FastValue.
+    fn to_type() -> Type;
+}
+
+impl FastValue for u64 {
+    fn from_u64(val: u64) -> Self {
+        val
+    }
+
+    fn to_u64(&self) -> u64 {
+        *self
+    }
+
+    fn fast_field_cardinality(field_type: &FieldType) -> Option<Cardinality> {
+        match *field_type {
+            FieldType::U64(ref integer_options) => integer_options.get_fastfield_cardinality(),
+            FieldType::Facet(_) => Some(Cardinality::MultiValues),
+            _ => None,
+        }
+    }
+
+    fn as_u64(&self) -> u64 {
+        *self
+    }
+
+    fn to_type() -> Type {
+        Type::U64
+    }
+}
+
+impl FastValue for i64 {
+    fn from_u64(val: u64) -> Self {
+        common::u64_to_i64(val)
+    }
+
+    fn to_u64(&self) -> u64 {
+        common::i64_to_u64(*self)
+    }
+
+    fn fast_field_cardinality(field_type: &FieldType) -> Option<Cardinality> {
+        match *field_type {
+            FieldType::I64(ref integer_options) => integer_options.get_fastfield_cardinality(),
+            _ => None,
+        }
+    }
+
+    fn as_u64(&self) -> u64 {
+        *self as u64
+    }
+
+    fn to_type() -> Type {
+        Type::I64
+    }
+}
+
+impl FastValue for f64 {
+    fn from_u64(val: u64) -> Self {
+        common::u64_to_f64(val)
+    }
+
+    fn to_u64(&self) -> u64 {
+        common::f64_to_u64(*self)
+    }
+
+    fn fast_field_cardinality(field_type: &FieldType) -> Option<Cardinality> {
+        match *field_type {
+            FieldType::F64(ref integer_options) => integer_options.get_fastfield_cardinality(),
+            _ => None,
+        }
+    }
+
+    fn as_u64(&self) -> u64 {
+        self.to_bits()
+    }
+
+    fn to_type() -> Type {
+        Type::F64
+    }
+}
+
+impl FastValue for bool {
+    fn from_u64(val: u64) -> Self {
+        val != 0u64
+    }
+
+    fn to_u64(&self) -> u64 {
+        match self {
+            false => 0,
+            true => 1,
+        }
+    }
+
+    fn fast_field_cardinality(field_type: &FieldType) -> Option<Cardinality> {
+        match *field_type {
+            FieldType::Bool(ref integer_options) => integer_options.get_fastfield_cardinality(),
+            _ => None,
+        }
+    }
+
+    fn as_u64(&self) -> u64 {
+        *self as u64
+    }
+
+    fn to_type() -> Type {
+        Type::Bool
+    }
+}
+
+impl FastValue for DateTime {
+    /// Converts a timestamp microseconds into DateTime.
+    ///
+    /// **Note the timestamps is expected to be in microseconds.**
+    fn from_u64(timestamp_micros_u64: u64) -> Self {
+        let timestamp_micros = i64::from_u64(timestamp_micros_u64);
+        Self::from_timestamp_micros(timestamp_micros)
+    }
+
+    fn to_u64(&self) -> u64 {
+        common::i64_to_u64(self.into_timestamp_micros())
+    }
+
+    fn fast_field_cardinality(field_type: &FieldType) -> Option<Cardinality> {
+        match *field_type {
+            FieldType::Date(ref options) => options.get_fastfield_cardinality(),
+            _ => None,
+        }
+    }
+
+    fn as_u64(&self) -> u64 {
+        self.into_timestamp_micros().as_u64()
+    }
+
+    fn to_type() -> Type {
+        Type::Date
+    }
+}
diff --git a/src/fastfield/mod.rs b/src/fastfield/mod.rs
index c6277a255..31d762c73 100644
--- a/src/fastfield/mod.rs
+++ b/src/fastfield/mod.rs
@@ -24,20 +24,22 @@ pub use self::alive_bitset::{intersect_alive_bitsets, write_alive_bitset, AliveB
 pub use self::bytes::{BytesFastFieldReader, BytesFastFieldWriter};
 pub use self::error::{FastFieldNotAvailableError, Result};
 pub use self::facet_reader::FacetReader;
+pub use self::fast_value::{FastValue, FastValueU128};
 pub(crate) use self::gcd::{find_gcd, GCDFastFieldCodec, GCD_CODEC_ID, GCD_DEFAULT};
 pub use self::multivalued::{MultiValuedFastFieldReader, MultiValuedFastFieldWriter};
-pub use self::reader::{DynamicFastFieldReader, FastFieldReader};
+pub use self::reader::{DynamicFastFieldReader, FastFieldReader, FastFieldReaderCodecWrapperU128};
 pub use self::readers::FastFieldReaders;
 pub(crate) use self::readers::{type_and_cardinality, FastType};
 pub use self::serializer::{CompositeFastFieldSerializer, FastFieldDataAccess, FastFieldStats};
 pub use self::writer::{FastFieldsWriter, IntFastFieldWriter};
-use crate::schema::{Cardinality, FieldType, Type, Value};
-use crate::{DateTime, DocId};
+use crate::schema::Value;
+use crate::DocId;
 
 mod alive_bitset;
 mod bytes;
 mod error;
 mod facet_reader;
+mod fast_value;
 mod gcd;
 mod multivalued;
 mod reader;
@@ -57,182 +59,6 @@ pub(crate) const ALL_CODECS: &[FastFieldCodecName; 3] = &[
     FastFieldCodecName::BlockwiseLinearInterpol,
 ];
 
-/// Trait for `BytesFastFieldReader` and `MultiValuedFastFieldReader` to return the length of data
-/// for a doc_id
-pub trait MultiValueLength {
-    /// returns the num of values associated to a doc_id
-    fn get_len(&self, doc_id: DocId) -> u64;
-    /// returns the sum of num values for all doc_ids
-    fn get_total_len(&self) -> u64;
-}
-
-/// Trait for types that are allowed for fast fields:
-/// (u64, i64 and f64, bool, DateTime).
-pub trait FastValue: Clone + Copy + Send + Sync + PartialOrd + 'static {
-    /// Converts a value from u64
-    ///
-    /// Internally all fast field values are encoded as u64.
-    /// **Note: To be used for converting encoded Term, Posting values.**
-    fn from_u64(val: u64) -> Self;
-
-    /// Converts a value to u64.
-    ///
-    /// Internally all fast field values are encoded as u64.
-    fn to_u64(&self) -> u64;
-
-    /// Returns the fast field cardinality that can be extracted from the given
-    /// `FieldType`.
-    ///
-    /// If the type is not a fast field, `None` is returned.
-    fn fast_field_cardinality(field_type: &FieldType) -> Option<Cardinality>;
-
-    /// Cast value to `u64`.
-    /// The value is just reinterpreted in memory.
-    fn as_u64(&self) -> u64;
-
-    /// Build a default value. This default value is never used, so the value does not
-    /// really matter.
-    fn make_zero() -> Self {
-        Self::from_u64(0i64.to_u64())
-    }
-
-    /// Returns the `schema::Type` for this FastValue.
-    fn to_type() -> Type;
-}
-
-impl FastValue for u64 {
-    fn from_u64(val: u64) -> Self {
-        val
-    }
-
-    fn to_u64(&self) -> u64 {
-        *self
-    }
-
-    fn fast_field_cardinality(field_type: &FieldType) -> Option<Cardinality> {
-        match *field_type {
-            FieldType::U64(ref integer_options) => integer_options.get_fastfield_cardinality(),
-            FieldType::Facet(_) => Some(Cardinality::MultiValues),
-            _ => None,
-        }
-    }
-
-    fn as_u64(&self) -> u64 {
-        *self
-    }
-
-    fn to_type() -> Type {
-        Type::U64
-    }
-}
-
-impl FastValue for i64 {
-    fn from_u64(val: u64) -> Self {
-        common::u64_to_i64(val)
-    }
-
-    fn to_u64(&self) -> u64 {
-        common::i64_to_u64(*self)
-    }
-
-    fn fast_field_cardinality(field_type: &FieldType) -> Option<Cardinality> {
-        match *field_type {
-            FieldType::I64(ref integer_options) => integer_options.get_fastfield_cardinality(),
-            _ => None,
-        }
-    }
-
-    fn as_u64(&self) -> u64 {
-        *self as u64
-    }
-
-    fn to_type() -> Type {
-        Type::I64
-    }
-}
-
-impl FastValue for f64 {
-    fn from_u64(val: u64) -> Self {
-        common::u64_to_f64(val)
-    }
-
-    fn to_u64(&self) -> u64 {
-        common::f64_to_u64(*self)
-    }
-
-    fn fast_field_cardinality(field_type: &FieldType) -> Option<Cardinality> {
-        match *field_type {
-            FieldType::F64(ref integer_options) => integer_options.get_fastfield_cardinality(),
-            _ => None,
-        }
-    }
-
-    fn as_u64(&self) -> u64 {
-        self.to_bits()
-    }
-
-    fn to_type() -> Type {
-        Type::F64
-    }
-}
-
-impl FastValue for bool {
-    fn from_u64(val: u64) -> Self {
-        val != 0u64
-    }
-
-    fn to_u64(&self) -> u64 {
-        match self {
-            false => 0,
-            true => 1,
-        }
-    }
-
-    fn fast_field_cardinality(field_type: &FieldType) -> Option<Cardinality> {
-        match *field_type {
-            FieldType::Bool(ref integer_options) => integer_options.get_fastfield_cardinality(),
-            _ => None,
-        }
-    }
-
-    fn as_u64(&self) -> u64 {
-        *self as u64
-    }
-
-    fn to_type() -> Type {
-        Type::Bool
-    }
-}
-
-impl FastValue for DateTime {
-    /// Converts a timestamp microseconds into DateTime.
-    ///
-    /// **Note the timestamps is expected to be in microseconds.**
-    fn from_u64(timestamp_micros_u64: u64) -> Self {
-        let timestamp_micros = i64::from_u64(timestamp_micros_u64);
-        Self::from_timestamp_micros(timestamp_micros)
-    }
-
-    fn to_u64(&self) -> u64 {
-        common::i64_to_u64(self.into_timestamp_micros())
-    }
-
-    fn fast_field_cardinality(field_type: &FieldType) -> Option<Cardinality> {
-        match *field_type {
-            FieldType::Date(ref options) => options.get_fastfield_cardinality(),
-            _ => None,
-        }
-    }
-
-    fn as_u64(&self) -> u64 {
-        self.into_timestamp_micros().as_u64()
-    }
-
-    fn to_type() -> Type {
-        Type::Date
-    }
-}
-
 fn value_to_u64(value: &Value) -> u64 {
     match value {
         Value::U64(val) => val.to_u64(),
@@ -244,6 +70,15 @@ fn value_to_u64(value: &Value) -> u64 {
     }
 }
 
+/// Trait for `BytesFastFieldReader` and `MultiValuedFastFieldReader` to return the length of data
+/// for a doc_id
+pub trait MultiValueLength {
+    /// returns the num of values associated to a doc_id
+    fn get_len(&self, doc_id: DocId) -> u64;
+    /// returns the sum of num values for all doc_ids
+    fn get_total_len(&self) -> u64;
+}
+
 /// The fast field type
 pub enum FastFieldType {
     /// Numeric type, e.g. f64.
@@ -280,9 +115,9 @@ mod tests {
     use super::*;
     use crate::directory::{CompositeFile, Directory, RamDirectory, WritePtr};
     use crate::merge_policy::NoMergePolicy;
-    use crate::schema::{Document, Field, Schema, FAST, STRING, TEXT};
+    use crate::schema::{Cardinality, Document, Field, Schema, FAST, STRING, TEXT};
     use crate::time::OffsetDateTime;
-    use crate::{DateOptions, DatePrecision, Index, SegmentId, SegmentReader};
+    use crate::{DateOptions, DatePrecision, DateTime, Index, SegmentId, SegmentReader};
 
     pub static SCHEMA: Lazy<Schema> = Lazy::new(|| {
         let mut schema_builder = Schema::builder();
diff --git a/src/fastfield/reader.rs b/src/fastfield/reader.rs
index 79f342c9b..de5a1b00a 100644
--- a/src/fastfield/reader.rs
+++ b/src/fastfield/reader.rs
@@ -1,5 +1,6 @@
 use std::collections::HashMap;
 use std::marker::PhantomData;
+use std::ops::RangeInclusive;
 use std::path::Path;
 
 use fastfield_codecs::bitpacked::{
@@ -11,9 +12,9 @@ use fastfield_codecs::linearinterpol::{
 use fastfield_codecs::multilinearinterpol::{
     MultiLinearInterpolFastFieldReader, MultiLinearInterpolFastFieldSerializer,
 };
-use fastfield_codecs::{FastFieldCodecReader, FastFieldCodecSerializer};
+use fastfield_codecs::{FastFieldCodecReader, FastFieldCodecReaderU128, FastFieldCodecSerializer};
 
-use super::{FastValue, GCDFastFieldCodec, GCD_CODEC_ID};
+use super::{FastValue, FastValueU128, GCDFastFieldCodec, GCD_CODEC_ID};
 use crate::directory::{CompositeFile, Directory, FileSlice, OwnedBytes, RamDirectory, WritePtr};
 use crate::fastfield::{CompositeFastFieldSerializer, FastFieldsWriter};
 use crate::schema::{Schema, FAST};
@@ -210,6 +211,47 @@ impl<Item: FastValue> FastFieldReader<Item> for DynamicFastFieldReader<Item> {
     }
 }
 
+/// Wrapper for accessing a fastfield.
+///
+/// Holds the data and the codec to the read the data.
+#[derive(Clone)]
+pub struct FastFieldReaderCodecWrapperU128<Item: FastValueU128, CodecReader> {
+    reader: CodecReader,
+    bytes: OwnedBytes,
+    _phantom: PhantomData<Item>,
+}
+
+impl<Item: FastValueU128, C: FastFieldCodecReaderU128> FastFieldReaderCodecWrapperU128<Item, C> {
+    /// Opens a fast field given the bytes.
+    pub fn open_from_bytes(bytes: OwnedBytes) -> crate::Result<Self> {
+        let reader = C::open_from_bytes(bytes.as_slice())?;
+        Ok(Self {
+            reader,
+            bytes,
+            _phantom: PhantomData,
+        })
+    }
+
+    /// Returns the item for the docid
+    pub fn get(&self, doc: u64) -> Option<Item> {
+        self.reader
+            .get(doc, self.bytes.as_slice())
+            .map(|el| Item::from_u128(el))
+    }
+
+    /// Iterates over all elements in the fast field
+    pub fn iter(&self) -> impl Iterator<Item = Option<Item>> + '_ {
+        self.reader
+            .iter(self.bytes.as_slice())
+            .map(|el| el.map(Item::from_u128))
+    }
+
+    /// Returns all docids which are in the provided range
+    pub fn get_range(&self, range: RangeInclusive<u128>) -> Vec<usize> {
+        self.reader.get_range(range, self.bytes.as_slice())
+    }
+}
+
 /// Wrapper for accessing a fastfield.
 ///
 /// Holds the data and the codec to the read the data.
diff --git a/src/fastfield/readers.rs b/src/fastfield/readers.rs
index 9f75baafd..4636261a8 100644
--- a/src/fastfield/readers.rs
+++ b/src/fastfield/readers.rs
@@ -1,4 +1,8 @@
-use super::reader::DynamicFastFieldReader;
+use std::net::IpAddr;
+
+use fastfield_codecs::ip_codec::IntervallDecompressor;
+
+use super::reader::{DynamicFastFieldReader, FastFieldReaderCodecWrapperU128};
 use crate::directory::{CompositeFile, FileSlice};
 use crate::fastfield::{
     BytesFastFieldReader, FastFieldNotAvailableError, FastValue, MultiValuedFastFieldReader,
@@ -137,6 +141,30 @@ impl FastFieldReaders {
         self.typed_fast_field_reader(field)
     }
 
+    /// Returns the `ip` fast field reader reader associated to `field`.
+    ///
+    /// If `field` is not a u128 fast field, this method returns an Error.
+    pub fn ip_addr(
+        &self,
+        field: Field,
+    ) -> crate::Result<FastFieldReaderCodecWrapperU128<IpAddr, IntervallDecompressor>> {
+        let fast_field_slice = self.fast_field_data(field, 0)?;
+        let bytes = fast_field_slice.read_bytes()?;
+        FastFieldReaderCodecWrapperU128::<IpAddr, IntervallDecompressor>::open_from_bytes(bytes)
+    }
+
+    /// Returns the `u128` fast field reader reader associated to `field`.
+    ///
+    /// If `field` is not a u128 fast field, this method returns an Error.
+    pub fn u128(
+        &self,
+        field: Field,
+    ) -> crate::Result<FastFieldReaderCodecWrapperU128<u128, IntervallDecompressor>> {
+        let fast_field_slice = self.fast_field_data(field, 0)?;
+        let bytes = fast_field_slice.read_bytes()?;
+        FastFieldReaderCodecWrapperU128::<u128, IntervallDecompressor>::open_from_bytes(bytes)
+    }
+
     /// Returns the `u64` fast field reader reader associated to `field`, regardless of whether the
     /// given field is effectively of type `u64` or not.
     ///
diff --git a/src/indexer/merger.rs b/src/indexer/merger.rs
index 5ab89e35f..899e07e77 100644
--- a/src/indexer/merger.rs
+++ b/src/indexer/merger.rs
@@ -2,6 +2,7 @@ use std::cmp;
 use std::collections::HashMap;
 use std::sync::Arc;
 
+use fastfield_codecs::ip_codec::{IntervalCompressor, IntervallDecompressor};
 use itertools::Itertools;
 use measure_time::debug_time;
 use tantivy_bitpacker::minmax;
@@ -11,7 +12,8 @@ use crate::docset::{DocSet, TERMINATED};
 use crate::error::DataCorruption;
 use crate::fastfield::{
     AliveBitSet, CompositeFastFieldSerializer, DynamicFastFieldReader, FastFieldDataAccess,
-    FastFieldReader, FastFieldStats, MultiValueLength, MultiValuedFastFieldReader,
+    FastFieldReader, FastFieldReaderCodecWrapperU128, FastFieldStats, MultiValueLength,
+    MultiValuedFastFieldReader,
 };
 use crate::fieldnorm::{FieldNormReader, FieldNormReaders, FieldNormsSerializer, FieldNormsWriter};
 use crate::indexer::doc_id_mapping::{expect_field_id_for_sort_field, SegmentDocIdMapping};
@@ -323,7 +325,11 @@ impl IndexMerger {
                 }
                 FieldType::Ip(options) => {
                     if options.is_fast() {
-                        // TODO create fast field for merge
+                        self.write_u128_single_fast_field(
+                            field,
+                            fast_field_serializer,
+                            doc_id_mapping,
+                        )?;
                     }
                 }
 
@@ -337,6 +343,50 @@ impl IndexMerger {
         Ok(())
     }
 
+    // used to merge `u128` single fast fields.
+    fn write_u128_single_fast_field(
+        &self,
+        field: Field,
+        fast_field_serializer: &mut CompositeFastFieldSerializer,
+        doc_id_mapping: &SegmentDocIdMapping,
+    ) -> crate::Result<()> {
+        let fast_field_readers = self
+            .readers
+            .iter()
+            .map(|reader| {
+                let u128_reader: FastFieldReaderCodecWrapperU128<u128, IntervallDecompressor> =
+                    reader.fast_fields().u128(field).expect(
+                        "Failed to find a reader for single fast field. This is a tantivy bug and \
+                         it should never happen.",
+                    );
+                u128_reader
+            })
+            .collect::<Vec<_>>();
+
+        let compressor = {
+            let vals = fast_field_readers
+                .iter()
+                .flat_map(|reader| reader.iter())
+                .flatten()
+                .collect::<Vec<u128>>();
+
+            IntervalCompressor::from_vals(vals)
+        };
+
+        let iter = doc_id_mapping.iter().map(|(doc_id, reader_ordinal)| {
+            let fast_field_reader = &fast_field_readers[*reader_ordinal as usize];
+            fast_field_reader
+                .get((*doc_id) as u64)
+                .unwrap_or(compressor.null_value)
+        });
+
+        let field_write = fast_field_serializer.get_field_writer(field, 0);
+
+        compressor.compress_into(iter, field_write)?;
+
+        Ok(())
+    }
+
     // used both to merge field norms, `u64/i64` single fast fields.
     fn write_single_fast_field(
         &self,
diff --git a/src/schema/field_type.rs b/src/schema/field_type.rs
index 1bf1577e7..112353373 100644
--- a/src/schema/field_type.rs
+++ b/src/schema/field_type.rs
@@ -67,9 +67,11 @@ pub enum Type {
     Json = b'j',
     /// IpAddr
     Ip = b'p',
+    /// IpAddr
+    U128 = b'1',
 }
 
-const ALL_TYPES: [Type; 10] = [
+const ALL_TYPES: [Type; 11] = [
     Type::Str,
     Type::U64,
     Type::I64,
@@ -80,6 +82,7 @@ const ALL_TYPES: [Type; 10] = [
     Type::Bytes,
     Type::Json,
     Type::Ip,
+    Type::U128,
 ];
 
 impl Type {
@@ -107,6 +110,7 @@ impl Type {
             Type::Bytes => "Bytes",
             Type::Json => "Json",
             Type::Ip => "Ip",
+            Type::U128 => "U128",
         }
     }
 
@@ -124,6 +128,7 @@ impl Type {
             b'b' => Some(Type::Bytes),
             b'j' => Some(Type::Json),
             b'p' => Some(Type::Ip),
+            b'1' => Some(Type::U128),
             _ => None,
         }
     }
diff --git a/src/schema/term.rs b/src/schema/term.rs
index a7f867451..1d6c2c324 100644
--- a/src/schema/term.rs
+++ b/src/schema/term.rs
@@ -419,6 +419,10 @@ fn debug_value_bytes(typ: Type, bytes: &[u8], f: &mut fmt::Formatter) -> fmt::Re
             let s = as_str(bytes); // TODO: change when serialization changes
             write_opt(f, s)?;
         }
+        Type::U128 => {
+            let s = as_str(bytes); // TODO: change when serialization changes
+            write_opt(f, s)?;
+        }
     }
     Ok(())
 }