msg="Attempted to dereference zero pointer"

[BENMADANI Houssem Eddine]

Hello,

 I'm trying to use flowmonitor with my similation scenario but i always have this error and i don't know what does it mean:

assert failed. cond="m_ptr", msg="Attempted to dereference zero pointer", +2.000000000s -1 file=./ns3/ptr.h, line=649
terminate called without an active exception.

I think this is happening due to the use of Flow monitor.

Can you help me solve this problem?

[Tommaso Pecorella]

Maybe a bug, maybe not. Impossible to say without the script and the ns-3 version. However, I guess you're using 3.38, RIGHT?

[BENMADANI Houssem Eddine]

i'm using 3.35, Sir.

[BENMADANI Houssem Eddine]

You will find in the attached file below my script, Sir.

I tried to run the script with 3.38 but i got the same message.

Best regards,

[Tommaso Pecorella]

I was about to post a warning about the fact that users are supposed to try their best to fix their own mistakes. But I didn't, and you didn't get the warning. Hence, I'll not yell too much.

<begin: soft-and-calm-voice>

• FlowMonitor is used to gather statistics about the flows in the simulation using IP addresses and TCP/UDP ports.
  
• What do you think it might happens if... you forget to install the TCP/IP stack in the nodes?
  
• Moreover, was it so difficult to use a debugger?
  
• Do you want to ask for help at the very fist issue without even trying to find it?
  
• [I could go on but it would start to become questionable]
  

<end: soft-and-calm-voice>

Note: normally for this kind of mistakes I go full Gordon Ramsay mode. L2Use a debugger.

[BENMADANI Houssem Eddine]

Thank you sir. I really appreciate your response. knowing that I tried to find a solution before coming to post it here.

I will keep your advice in mind and make sure to utilize the appropriate debugging tools and techniques before asking for help in the future. Thank you for your feedback and guidance.

Best regards,