A method comprising: receiving, with a Dynamic Host Configuration Protocol "DHCP" relay of a network, a first DHCP discover message from a first client device of the network requesting that a first layer three "L3" network address be reserved for the first client device, wherein the first DHCP discover message includes a first identifier that uniquely identifies the first client device and an option 60 field defining a first portion of additional context information that identifies a vendor of the first client device; determining, with the DHCP relay, a second portion of the additional context information for the first DHCP discover message from the first client device that identifies a circuit by which the DHCP relay received the first DHCP discover message; receiving, with the DHCP relay, a second DHCP discover message from a second client device of the network different from the first client device requesting that a second L3 network address be reserved for use by the second client device within the network, wherein the second DHCP discover message includes a second identifier different from the first identifier that uniquely identifies the second client device and an option 60 field defining the same first portion of additional context information that identifies the same vendor of the second client device as that of the first client device; determining, with the DHCP relay, the same second portion of the additional context information for the second DHCP discover message from the second client device that identifies the same circuit for the second DHCP discover message as that determined for the first DHCP discover message; determining, with the DHCP relay, whether the additional context information associated with the first and second client devices is the same and whether the first identifier is different from the second identifier; based on the determination that the additional context information associated with the first and second client devices is the same and that the first identifier is different from the second identifier, determining that the first client device has failed gracelessly without issuing a DHCP release message; and automatically issuing a DHCP release message to a DHCP server, with the DHCP relay, to release the first network resource reserved for use by the first client device within the network based on the determination that the first client device has failed gracelessly without issuing a DHCP release message. receiving, with a Dynamic Host Configuration Protocol "DHCP" relay of a network, a first DHCP discover message from a first client device of the network requesting that a first layer three "L3" network address be reserved for the first client device, wherein the first DHCP discover message includes a first identifier that uniquely identifies the first client device and an option 60 field defining a first portion of additional context information that identifies a vendor of the first client device; determining, with the DHCP relay, a second portion of the additional context information for the first DHCP discover message from the first client device that identifies a circuit by which the DHCP relay received the first DHCP discover message; receiving, with the DHCP relay, a second DHCP discover message from a second client device of the network different from the first client device requesting that a second L3 network address be reserved for use by the second client device within the network, wherein the second DHCP discover message includes a second identifier different from the first identifier that uniquely identifies the second client device and an option 60 field defining the same first portion of additional context information that identifies the same vendor of the second client device as that of the first client device; determining, with the DHCP relay, the same second portion of the additional context information for the second DHCP discover message from the second client device that identifies the same circuit for the second DHCP discover message as that determined for the first DHCP discover message; determining, with the DHCP relay, whether the additional context information associated with the first and second client devices is the same and whether the first identifier is different from the second identifier; based on the determination that the additional context information associated with the first and second client devices is the same and that the first identifier is different from the second identifier, determining that the first client device has failed gracelessly without issuing a DHCP release message; and automatically issuing a DHCP release message to a DHCP server, with the DHCP relay, to release the first network resource reserved for use by the first client device within the network based on the determination that the first client device has failed gracelessly without issuing a DHCP release message.