ns-3 library cannot recognize IPv4 address of example

[lorenzosaino]

The ns-3 example fails starting with ns-3.18, although it works fine with ns-3.16.

The issue arises when, parsing the example topology, ns-3 tries to set the property RemoteAddress of the UdpEchoClient application to 3-4-0a:00:00:06 in which 3 is the address type, 4 is the lenght in bytes of the address and 0a:00:00:06 is the actual address, i.e. 10.0.0.6.

The specific problem occurs here:

assert failed. cond="address.m_len <= Address::MAX_SIZE", file=../src/network/model/address.cc, line=274

because somehow ns-3 thinks that the address length (4) is greater than Address::MAX_SIZE which is 20. If I edit the MAX_SIZE value in address.h to, for example, 200, then the assertion passes, but UDP packets are not received by the echo server during the simulation. This however might occur because of a change in address assignments.

I noticed that between ns-3.16 and ns-3.18 the Address attribute storing the length, i.e. m_length, as well as the return type of AsInt changed from uint32_t to unit8_t but this does not seem to be issue because the string -> uint8_t conversion appears to work fine with 4 (although it would fail with 04).