anchor.diff:  client.set_l3_mode(port = 1, src_ipv4 = '1.1.2.2', dst_ipv4 = '1.1.2.1')
   
   # ping port 1 from port 0 through the router
  -client.ping_ip(src_port = 0, dst_ipv4 = '1.1.2.2', pkt_size = 64)
  +client.ping_ip(src_port = 0, dst_ipv4 = '1.1.2.2', pkt_size = 64)        <1>
       
   # disable service mode
   client.set_service_mode(enabled = False)
   
   ----
  -
  +<1> Check connectivity
  +
  +
  +==== IPv6 ND/DHCP client
  +
  +in progress 
   
   
   === Tutorials
  
positive.code: * *Layer 3 mode* - IPv4/IPv6 configuration
  
  When configuring a port for L2 mode, it is only required to provide
  the destination MAC address for the port.
  
  When configuring a port for L3, it is required to provide both
  source IPv4/IPv6 address and a IPv4/IPv6 destination address.
  
negative.code: It is possible, under service mode to ping the DUT or even a TRex port
  from the console / API.
  
  .TRex Console
  [source,bash]
  ----
  
  trex(service)>ping --help
  usage: ping [-h] --port PORT -d PING_IPV4 [-s PKT_SIZE] [-n COUNT]
  