## Summary `SixLowPanMesh::Deserialize()` reads the originator and final-destination address bytes with `Address::CopyFrom()` without first setting the address type via `Address::SetType()`. The address stays UNASSIGNED, and a later `CopyFrom` on it triggers an assertion failure: ``` NS_ASSERT failed, cond="m_type != UNASSIGNED_TYPE", msg="Type-0 addresses are reserved. Please use SetType before using CopyFrom." (src/network/model/address.cc) ``` ## Reproduction Run `example-ping-lr-wpan-mesh-under` in an asserts-enabled build (both debug and optimized). It aborts with SIGABRT, the failure surfacing in `LrWpanMac::EnqueueTxQElement`. ## Affected version Current master. ## Fix Set the address type before `CopyFrom` for both `m_src` and `m_dst` in `SixLowPanMesh::Deserialize`: ``` m_src.SetType("MacAddress", addrSize); m_dst.SetType("MacAddress", addrSize); ``` Fix provided by Tommaso Pecorella; verified locally, the example then runs clean (5/5 pings, 0% loss).