anchor.diff:  However, there is no way to create corrupted L1 fields (Like Ethernet FCS), since these are usually handled by the NIC hardware.
   
   ==== Why the performance is low?
  -What would reduce the performance: 
  +Major things that can reduce the performance are:
   
   1. Many concurent streams.
   2. Complex field engine program.
  
positive.code: You can use the simulator. see link:trex_manual.html#_simulator[simulator]
  The output of the simulator can be loaded to Excel. The CPS can be tuned.
  
  ==== I want to have more active flows on the DUT, how can I do it?
  After stretching TRex to its maximum CPS capacity, consider the following: DUT will have much more active flows in case of a UDP flow due to the nature of aging (DUT does not know when the flow ends while TRex knows).
  In order to artificialy increse the length of the active flows in TRex, you can config larger IPG in the YAML file. This will cause each flow to last longer. Alternatively, you can increase IPG in your PCAP file as well.
  
  
  ==== How do I support more active flows?
  The default maximum supported flows are 1M total (TRex prospective). DUT could have much more due to aging. When active flows are more than 1M flows there is message that there is no enough memory. 
  
  [source,Python]
  --------
  Active-flows    :  1045562  Clients :    80120   Socket-util : 0.0207 %
  --------
  
  Look link:trex_manual.html#_memory_section_configuration[here]
  
  This example support 10M flows 
  
  [source,Python]
  --------
  - port_limit    : 2
    version       : 2
    interfaces    : ['04:00.0', '0c:00.0']   # list of the interfaces to bind run ./dpdk_nic_bind.py --status 
    port_info       :  # set eh mac addr 
  
            - dest_mac        :   [0x18, 0x8b, 0x9d, 0xa3, 0xae, 0x84]
              src_mac         :   [0x18, 0x8b, 0x9d, 0xa3, 0xae, 0x83]
              
            - dest_mac        :   [0x18, 0x8b, 0x9d, 0xa3, 0xae, 0x83]
              src_mac         :   [0x18, 0x8b, 0x9d, 0xa3, 0xae, 0x84]
  
    memory    :                                          
          dp_flows    : 10048576   <1>
  --------
  <1> 10M flows
  
  
  ==== I am getting and error: The number of ips should be at least number of threads 
  The range of clients and servers should be at least the number of threads. 
  The number of threads is equal to (number of port pairs) * (-c value)
  
  ==== Incoming frames are of type SCTP. Why?
  Default latency packets are SCTP, you can remove `-l 1000` or change it to ICMP see manual for more info.
   
  ==== Is there a configuration guide to Linux as a router (static ARP)?
  have a look link:https://groups.google.com/forum/#!topic/trex-tgn/YQcQtA8A8hA[linux as a router]
  
  ===  Stateless 
  
  ==== How do I get started with stateless mode?
  
negative.code: ==== TRex traffic does not show up on Wireshark, so I can not capture the traffic from the TRex port
  TRex uses DPDK which takes ownership of the ports, so using Wireshark is not possible. You can use switch with port mirroring to capture the traffic.
  
  ===  Stateful 
  
  ==== How do I start using the stateful mode?
  You should first have a YAML configuration file. See link:trex_manual.html#_traffic_yaml_parameter_of_f_option[here].
  Then, you can find some basic examples link:trex_manual.html#_trex_command_line[here].
  
  ==== TRex is connected to a switch and I observe many dropped packets at TRex startup.
  A switch might be configured with spanning tree enabled. TRex reset the port at startup, making the switch reset it side as well,
  and spanning tree can drop the packets until it stabilizes.
  Disabling spanning tree can help. On Cisco nexus, you can do that using `spanning-tree port type edge`
  You can also start Cisco with -k <num> flag. This will send packets for k seconds before starting the actual test, letting the spanning
  tree time to stabilize.
  This issue will be fixed when we consolidate ``Stateful'' and ``Stateless'' RPC.
  
  ==== I can not see RX packets
  TRex does not support ARP yet, you should configure the DUT to send the packets to the TRex port MAC address. From Stateless mode, you can change the port mode to promiscuous. +
  