VPCS crashing under GNS3 v2.2.26 / VPCS v0.8.2 / MacOS v11.6

[nanocat-net]

I'm using VPCS with my small networking class, because they're very lightweight and don't require the GNS3 VM to be installed.

I have 4 VPCS devices in the GNS3 project, connected to a GNS3 Switch. I am able to start the VPCS successfully, and perhaps I'm even able to run a couple of commands - I was able to configure the IP address for example - and then the VPCS will suddenly quit without warning.

The VPCS prints "Good-bye" and then closes the connection. GNS3 shows that the VPCS is still running.

When I telnet to the still-running VPCS, I get the same result:

~ ➜ telnet 127.0.0.1 5003
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.

Good-bye
Connection closed by foreign host.
~ ➜

Here's a full session showing a crash. The crash happened upon me pressing the up arrow key to recall the previous command. This time, the host doesn't tell me Good-bye, it just closes my connection.

~ ➜ telnet 127.0.0.1 5004
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.

sales02>
sales02>
sales02> ip address 192.168.10.11/24 192.168.20.1
Invalid address

sales02> ip 192.168.10.11/24 192.168.20.1
not same subnet

sales02> ip 192.168.10.11/24 192.168.10.1
Checking for duplicate address...
sales02 : 192.168.10.11 255.255.255.0 gateway 192.168.10.1

sales02> ping 192.168.10.10

host (192.168.10.10) not reachable

sales02> Connection closed by foreign host.
~ took 41s ➜
~ ➜
~ ➜
~ ➜ telnet 127.0.0.1 5004
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
Connection closed by foreign host.
~ ➜

When I launch a VPCS manually from the command line using /Applications/GNS3.app/Contents/MacOS/vpcs -p 10001, it doesn't crash after telnetting to localhost:10001 and messing with it for some time.