ifeq ($(USE_NETWORK),)
  else
    NETWORK_OPT = -DUSE_NETWORK -isystem /usr/local/include
    /usr/local/lib/libpcap.dylib
  endif

  ifneq (,$(NETWORK_USEFUL))
    ifneq (,$(call find_include,pcap))
      ifneq (,$(call find_lib,$(PCAPLIB)))
        ifneq ($(USE_NETWORK),) # Network support specified on the GNU make command line
          NETWORK_CCDEFS = -DUSE_NETWORK -I$(dir $(call find_include,pcap))
          ifeq (cygwin,$(OSTYPE))
            # cygwin has no ldconfig so explicitly specify pcap object library
            NETWORK_LDFLAGS = -L$(dir $(call find_lib,$(PCAPLIB))) -Wl,-R,$(dir $(call find_lib,$(PCAPLIB))) -l$(PCAPLIB)
          else
            NETWORK_LDFLAGS = -l$(PCAPLIB)
          endif
          $(info using libpcap: $(call find_lib,$(PCAPLIB)) $(call find_include,pcap))
          NETWORK_FEATURES = - static networking support using $(OSNAME) provided libpcap components
        else # default build uses dynamic libpcap
          NETWORK_CCDEFS = -DUSE_SHARED -I$(dir $(call find_include,pcap))
          $(info using libpcap: $(call find_include,pcap))
          NETWORK_FEATURES = - dynamic networking support using $(OSNAME) provided libpcap components
        endif
      else
        NETWORK_CCDEFS = -DUSE_SHARED -I$(dir $(call find_include,pcap))
        NETWORK_FEATURES = - dynamic networking support using $(OSNAME) provided libpcap components
        $(info using libpcap: $(call find_include,pcap))
      endif
    else
      # Look for package built from tcpdump.org sources with default install target (or cygwin winpcap)
      LIBPATH += /usr/local/lib
      INCPATH += /usr/local/include
      LIBEXTSAVE := $(LIBEXT)
      LIBEXT = a
      ifneq (,$(call find_lib,$(PCAPLIB)))
        ifneq (,$(call find_include,pcap))
          $(info using libpcap: $(call find_lib,$(PCAPLIB)) $(call find_include,pcap))
          ifeq (cygwin,$(OSTYPE))
            NETWORK_CCDEFS = -DUSE_NETWORK -I$(dir $(call find_include,pcap))
            NETWORK_LDFLAGS = -L$(dir $(call find_lib,$(PCAPLIB))) -Wl,-R,$(dir $(call find_lib,$(PCAPLIB))) -l$(PCAPLIB)
            NETWORK_FEATURES = - static networking support using libpcap components located in the cygwin directories
          else
            NETWORK_CCDEFS := -DUSE_NETWORK -isystem $(dir $(call find_include,pcap)) $(call find_lib,$(PCAPLIB))
            NETWORK_FEATURES = - networking support using libpcap components from www.tcpdump.org
            $(info *** Warning ***)
            $(info *** Warning *** $(BUILD_SINGLE)Simulator$(BUILD_MULTIPLE) being built with networking support using)
            $(info *** Warning *** libpcap components from www.tcpdump.org.)
            $(info *** Warning *** Some users have had problems using the www.tcpdump.org libpcap)
            $(info *** Warning *** components for simh networking.  For best results, with)
            $(info *** Warning *** simh networking, it is recommended that you install the)
            $(info *** Warning *** libpcap-dev package from your $(OSTYPE) distribution)
            $(info *** Warning ***)
          endif
        else
          $(error using libpcap: $(call find_lib,$(PCAPLIB)) missing pcap.h)
        endif
      endif
      LIBEXT = $(LIBEXTSAVE)
    endif
    ifneq (,$(findstring USE_NETWORK,$(NETWORK_CCDEFS))$(findstring USE_SHARED,$(NETWORK_CCDEFS)))
	  # Given we have libpcap components, consider other network connections as well
      ifneq (,$(call find_lib,vdeplug))
        # libvdeplug requires the use of the OS provided libpcap
		ifeq (,$(findstring usr/local,$(NETWORK_CCDEFS)))
          ifneq (,$(call find_include,libvdeplug))
            # Provide support for vde networking
            NETWORK_CCDEFS += -DUSE_VDE_NETWORK
            NETWORK_LDFLAGS += -lvdeplug
            $(info using libvdeplug: $(call find_lib,vdeplug) $(call find_include,libvdeplug))
          endif
        endif
      endif
      ifneq (,$(call find_include,linux/if_tun))
        # Provide support for Tap networking on Linux
        NETWORK_CCDEFS += -DUSE_TAP_NETWORK
      endif
      ifeq (bsdtuntap,$(shell if $(TEST) -e /usr/include/net/if_tun.h -o -e /Library/Extensions/tap.kext; then echo bsdtuntap; fi))
        # Provide support for Tap networking on BSD platforms (including OS X)
        NETWORK_CCDEFS += -DUSE_TAP_NETWORK -DUSE_BSDTUNTAP
      endif
    else
      NETWORK_FEATURES = - WITHOUT networking support
      $(info *** Warning ***)
      $(info *** Warning *** $(BUILD_SINGLE)Simulator$(BUILD_MULTIPLE) are being built WITHOUT networking support)
      $(info *** Warning ***)
      $(info *** Warning *** To build simulator(s) with networking support you should read)
      $(info *** Warning *** 0readme_ethernet.txt and follow the instructions regarding the)
      $(info *** Warning *** needed libpcap components for your $(OSTYPE) platform)
      $(info *** Warning ***)
    endif
    NETWORK_OPT = $(NETWORK_CCDEFS)
  endif