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diff --git a/src/lib/dhcp/option6_pdexclude.h b/src/lib/dhcp/option6_pdexclude.h
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+// Copyright (C) 2016-2022 Internet Systems Consortium, Inc. ("ISC")
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+#ifndef OPTION6_PDEXCLUDE_H
+#define OPTION6_PDEXCLUDE_H
+
+#include <asiolink/io_address.h>
+#include <dhcp/option.h>
+#include <boost/shared_ptr.hpp>
+#include <stdint.h>
+
+namespace isc {
+namespace dhcp {
+
+/// @brief DHCPv6 option class representing Prefix Exclude Option (RFC 6603).
+///
+/// This class represents DHCPv6 Prefix Exclude option (67). This option is
+/// carried in the IA Prefix option and it conveys a single prefix which is
+/// used by the delegating router to communicate with a requesting router on
+/// the requesting router's uplink. This prefix is not used on the
+/// requesting router's downlinks (is excluded from other delegated prefixes).
+class Option6PDExclude: public Option {
+public:
+
+    /// @brief Constructor.
+    ///
+    /// @param delegated_prefix Delegated prefix.
+    /// @param delegated_prefix_length Delegated prefix length.
+    /// @param excluded_prefix Excluded prefix.
+    /// @param excluded_prefix_length Excluded prefix length.
+    ///
+    /// @throw BadValue if prefixes are invalid, if excluded prefix length
+    /// is not greater than delegated prefix length or if common parts of
+    /// prefixes does not match.
+    Option6PDExclude(const isc::asiolink::IOAddress& delegated_prefix,
+                     const uint8_t delegated_prefix_length,
+                     const isc::asiolink::IOAddress& excluded_prefix,
+                     const uint8_t excluded_prefix_length);
+
+    /// @brief Constructor, creates option instance from part of the buffer.
+    ///
+    /// This constructor is mostly used to parse Prefix Exclude options in the
+    /// received messages.
+    ///
+    /// @param begin Lower bound of the buffer to create option from.
+    /// @param end Upper bound of the buffer to create option from.
+    Option6PDExclude(OptionBufferConstIter begin, OptionBufferConstIter end);
+
+    /// @brief Copies this option and returns a pointer to the copy.
+    virtual OptionPtr clone() const;
+
+    /// @brief Writes option in wire-format to a buffer.
+    ///
+    /// Writes option in wire-format to buffer, returns pointer to first unused
+    /// byte after stored option (that is useful for writing options one after
+    /// another).
+    ///
+    /// The format of the option includes excluded prefix length specified as
+    /// a number of bits. It also includes IPv6 subnet ID field which is
+    /// computed from the delegated and excluded prefixes, according to the
+    /// section 4.2 of RFC 6603.
+    ///
+    /// @param [out] buf Pointer to a buffer.
+    /// @param check if set to false, allows options larger than 255 for v4
+    virtual void pack(isc::util::OutputBuffer& buf, bool check = true) const;
+
+    /// @brief Parses received buffer.
+    ///
+    /// @param begin iterator to first byte of option data
+    /// @param end iterator to end of option data (first byte after option end)
+    virtual void unpack(OptionBufferConstIter begin, OptionBufferConstIter end);
+
+    /// @brief Returns length of the complete option (data length + DHCPv6
+    /// option header)
+    ///
+    /// @return length of the option
+    virtual uint16_t len() const;
+
+    /// @brief Returns Prefix Exclude option in textual format.
+    ///
+    /// @param indent Number of spaces to be inserted before the text.
+    virtual std::string toText(int indent = 0) const;
+
+    /// @brief Returns excluded prefix.
+    ///
+    /// Assembles excluded prefix from a delegated prefix and IPv6 subnet id
+    /// specified as in RFC6603, section 4.2.
+    ///
+    /// @param delegated_prefix Delegated prefix for which excluded prefix will
+    /// be returned.
+    /// @param delegated_prefix_length Delegated prefix length.
+    asiolink::IOAddress
+    getExcludedPrefix(const asiolink::IOAddress& delegated_prefix,
+                      const uint8_t delegated_prefix_length) const;
+
+    /// @brief Returns excluded prefix length.
+    uint8_t getExcludedPrefixLength() const {
+        return (excluded_prefix_length_);
+    }
+
+    /// @brief Returns an excluded prefix in a binary format.
+    const std::vector<uint8_t>& getExcludedPrefixSubnetID() const {
+        return (subnet_id_);
+    }
+
+private:
+
+    /// @brief Returns IPv6 subnet ID length in octets.
+    ///
+    /// The IPv6 subnet ID length is between 1 and 16 octets.
+    uint8_t getSubnetIDLength(const uint8_t delegated_prefix_length,
+                              const uint8_t excluded_prefix_length) const;
+
+    /// @brief Holds excluded prefix length.
+    uint8_t excluded_prefix_length_;
+
+    /// @brief Subnet identifier as described in RFC6603, section 4.2.
+    std::vector<uint8_t> subnet_id_;
+};
+
+/// @brief Pointer to the @ref Option6PDExclude object.
+typedef boost::shared_ptr<Option6PDExclude> Option6PDExcludePtr;
+
+} // isc::dhcp namespace
+} // isc namespace
+
+#endif // OPTION6_PDEXCLUDE_H