I tried SecureCRT and had the same problem as have several people. The issue is that SecureCRT sends an abort (RST) when you disconnect. I think this normally locks the port in a time-wait condition, but in the GNS3-IOU VM Server this seems to cause the GNS3-server to close the instance listening on that port (192.168.1.99 is the server in this cap):
Code:
12107 2151.566261000 192.168.1.69 192.168.1.99 TCP 54 19142?4001 [RST, ACK] Seq=25 Ack=42 Win=0 Len=0
Putty doesn't cause the same issue because it terminates the connection:
Code:
11583 1841.332889000 192.168.1.69 192.168.1.99 TCP 54 19137?4001 [FIN, ACK] Seq=29 Ack=19 Win=65536 Len=0
11584 1841.333361000 192.168.1.99 192.168.1.69 TCP 60 4001?19137 [FIN, ACK] Seq=19 Ack=30 Win=29312 Len=0