diff --git a/BasiliskII/src/MacOSX/etherhelpertool.c b/BasiliskII/src/MacOSX/etherhelpertool.c
new file mode 100644
index 00000000..392f871a
--- /dev/null
+++ b/BasiliskII/src/MacOSX/etherhelpertool.c
@@ -0,0 +1,578 @@
+/*
+ *  etherhelpertool.c - Reads and writes raw ethernet packets usng bpf
+ *  interface.
+ *
+ *  Copyright (C) 2010, Daniel Sumorok
+ *
+ *  Basilisk II (C) 1997-2008 Christian Bauer
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <stdio.h>
+#include <string.h>
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <net/if_dl.h>
+#include <ifaddrs.h>
+#include <errno.h>
+#include <sys/select.h>
+
+#include <unistd.h>
+
+#include <net/if.h>
+#include <sys/time.h>
+#include <sys/ioctl.h>
+#include <net/bpf.h>
+#include <fcntl.h>
+
+#include <strings.h>
+
+#include <Carbon/Carbon.h>
+
+#define STR_MAX 256
+#define MAX_ARGV 10
+
+static int open_bpf(char *ifname);
+static int open_tap(char *ifname);
+static int retreive_auth_info(void);
+static int main_loop(int sd, int use_bpf);
+static int run_cmd(const char *cmd);
+static void handler(int signum);
+static int install_signal_handlers();
+static void do_exit();
+
+static int remove_bridge = 0;
+static const char *exec_name = "etherhelpertool";
+
+int main(int argc, char **argv)
+{
+	char *if_name;
+	int ret = 255;
+	int sd;
+        int tapNum;
+        int use_bpf;
+
+	if (argc != 2) {
+		return 255;
+	}
+	
+	if_name = argv[1];
+
+        do {
+                ret = retreive_auth_info();
+                if (ret != 0) {
+			fprintf(stderr, "%s: authorization failed.\n",
+				exec_name);
+			ret = 254;
+			break;
+                }
+
+		if (strncmp(if_name, "tap", 3) == 0) {
+                        sd = open_tap(if_name);
+                        use_bpf = 0;
+                } else {
+                        sd = open_bpf(if_name);
+                        use_bpf = 1;
+                }
+
+                if (sd < 0) {
+			fprintf(stderr, "%s: open device failed.\n",
+				exec_name);
+                        ret = 253;
+                        break;
+                }
+
+                if (install_signal_handlers() != 0) {
+			fprintf(stderr, 
+				"%s: failed to install signal handers.\n",
+				exec_name);
+                        ret = 252;
+                        break;
+                }
+
+                ret = main_loop(sd, use_bpf);
+                close(sd);
+        } while (0);
+
+        do_exit();
+
+	return ret;
+}
+
+static int main_loop(int sd, int use_bpf)
+{
+	fd_set readSet;
+	char *outgoing, *incoming;
+	unsigned short *out_len;
+	unsigned short *in_len;
+	int in_index, out_index;
+	u_int blen = 0;
+	int ret;
+	int fret = 0;
+	struct bpf_hdr *hdr;
+	int pkt_len;
+	int frame_len;
+	int pad;
+        char c = 0;
+
+	if (use_bpf) {
+                if (ioctl(sd, BIOCGBLEN, &blen) < 0) {
+			fprintf(stderr, 
+				"%s: ioctl() failed.\n",
+				exec_name);
+                        return -1;
+                }
+        } else {
+                blen = 4096;
+        }
+
+	incoming = malloc(blen);
+	if (incoming == NULL) {
+		fprintf(stderr, 
+			"%s: malloc() failed.\n",
+			exec_name);
+		return -2;
+	}
+
+	outgoing = malloc(blen);
+	if (outgoing == NULL) {
+		free(outgoing);
+		fprintf(stderr, 
+			"%s: malloc() failed.\n",
+			exec_name);
+		return -3;
+	}
+
+	in_index = 0;
+	out_index = 0;
+
+	out_len = (unsigned short *)outgoing;
+
+        /* Let our parent know we are ready for business. */
+        write(0, &c, 1);
+
+	while (1) {
+		int i;
+		FD_ZERO(&readSet);
+		FD_SET(0, &readSet);
+		FD_SET(sd, &readSet);
+
+		ret = select(sd + 1, &readSet, NULL, NULL, NULL);
+		if (ret < 0) {
+			fprintf(stderr, 
+				"%s: select() failed.\n",
+				exec_name);
+			fret = -4;
+			break;
+		}
+
+		if (FD_ISSET(0, &readSet)) {
+			if (out_index < 2) {
+				ret = read(0, outgoing + out_index, 2-out_index);
+			} else {
+				ret = read(0, outgoing + out_index, *out_len - out_index + 2);
+			}
+
+			if (ret < 1) {
+				if(ret < 0) {
+					fprintf(stderr, 
+						"%s: read() failed.\n",
+						exec_name);
+				}
+				fret = -5;
+				break;
+			}
+
+			out_index += ret;
+			if (out_index > 1) {
+				if ((*out_len + 2) > blen) {
+					fret = -6;
+					break;
+				}
+
+				if (out_index == (*out_len + 2)) {
+					ret = write(sd, out_len + 1, *out_len);
+					if (ret != *out_len) {
+						fprintf(stderr, 
+							"%s: write() failed.\n",
+							exec_name);
+						fret = -7;
+						break;
+					}
+					out_index = 0;
+				}
+			}
+
+		}
+
+		if (use_bpf && FD_ISSET(sd, &readSet)) {
+			int i;
+
+			ret = read(sd, incoming, blen);
+			if (ret < 1) {
+				if(ret < 0) {
+					fprintf(stderr, 
+						"%s: read() failed %d.\n",
+						exec_name, errno);
+				}
+				fret = -8;
+				break;
+			}
+
+			hdr = (struct bpf_hdr *)incoming;
+			in_len = (unsigned short *)(incoming + 16);
+
+			do {
+				pkt_len = hdr->bh_caplen;
+				frame_len = pkt_len + 18;
+
+				if ((pkt_len < 0) || (frame_len > ret) || (frame_len < 0)) {
+					fret = -9;
+					break;
+				}
+				*in_len = pkt_len;
+
+				if (write(0, in_len, pkt_len + 2) < (pkt_len + 2)) {
+                                        fret = -10;
+                                        break;
+                                }
+
+				if ((frame_len & 0x03) == 0) {
+					pad = 0;
+				} else {
+					pad = 4 - (frame_len & 0x03);
+				}
+
+				ret -= (frame_len + pad);
+				hdr = (struct bpf_hdr *)((unsigned char *)hdr + frame_len + pad);
+				in_len = (unsigned short *)((unsigned char *)hdr + 16);
+			} while (ret > 0);
+
+			if (fret != 0) {
+				fprintf(stderr, 
+					"%s: fret == %d.\n",
+					exec_name, fret);
+				break;
+			}
+		}
+
+		if (!use_bpf && FD_ISSET(sd, &readSet)) {
+			in_len = (unsigned short *)incoming;
+
+			pkt_len = read(sd, in_len + 1, blen-2);
+			if (pkt_len < 14) {
+				fprintf(stderr, 
+					"%s: read() returned %d.\n",
+					exec_name, pkt_len);
+				fret = -8;
+				break;
+			}
+
+                        *in_len = pkt_len;
+                        if (write(0, in_len, pkt_len + 2) < (pkt_len + 2)) {
+				fprintf(stderr, 
+					"%s: write() failed\n",
+					exec_name);
+                                fret = -10;
+                                break;
+                        }
+
+                }
+
+	}
+
+	free(incoming);
+	free(outgoing);
+
+	return fret;
+}
+
+static int retreive_auth_info(void)
+{
+	AuthorizationRef aRef;
+	OSStatus status;
+	AuthorizationRights myRights;
+	AuthorizationRights *newRights;
+	AuthorizationItem *myItem;
+	AuthorizationItem myItems[1];
+	AuthorizationItemSet *mySet;
+	int i;
+
+	status = AuthorizationCopyPrivilegedReference(&aRef, kAuthorizationFlagDefaults);
+	if (status != errAuthorizationSuccess) {
+		return -1;
+	}
+
+	status = AuthorizationCopyInfo(aRef, NULL, &mySet);
+	if (status != errAuthorizationSuccess) {
+		AuthorizationFree(aRef, kAuthorizationFlagDestroyRights);
+		return -1;
+	}
+
+	myItems[0].name = "system.privilege.admin";
+	myItems[0].valueLength = 0;
+	myItems[0].value = NULL;
+	myItems[0].flags = 0;
+
+	myRights.count = sizeof (myItems) / sizeof (myItems[0]);
+	myRights.items = myItems;
+
+	status = AuthorizationCopyRights(aRef, &myRights, NULL,
+					 kAuthorizationFlagExtendRights,
+					 &newRights);
+	if (status != errAuthorizationSuccess) {
+		AuthorizationFreeItemSet(mySet);
+		AuthorizationFree(aRef, kAuthorizationFlagDestroyRights);
+		return -2;
+	}
+
+	AuthorizationFreeItemSet(newRights);
+	AuthorizationFreeItemSet(mySet);
+	AuthorizationFree(aRef, kAuthorizationFlagDestroyRights);  
+
+	return 0;
+}
+
+static int open_tap(char *ifname)
+{
+        char str[STR_MAX] = {0};
+        char ifstr[STR_MAX] = {0};
+	char *interface;
+	char *address = NULL;
+	char *netmask = NULL;
+	char *bridge = NULL;
+	char *bridged_if = NULL;
+        int sd;
+
+	snprintf(ifstr, STR_MAX, "%s", ifname);
+	interface = strtok(ifstr, "/");
+	bridge = strtok(NULL, "/");
+	if (bridge != NULL) {
+		bridged_if = strtok(NULL, "/");
+	}
+	interface = strtok(ifstr, ":");
+
+	address = strtok(NULL, ":");
+
+	if (address != NULL) {
+		netmask = strtok(NULL, ":");
+	}
+
+        snprintf(str, STR_MAX, "/dev/%s", interface);
+
+        sd = open(str, O_RDWR);
+        if (sd < 0) {
+		fprintf(stderr, "%s: Failed to open %s\n",
+			exec_name, interface);
+                return -1;
+        }
+
+	if (address == NULL) {
+		snprintf(str, STR_MAX, "/sbin/ifconfig %s up", interface);
+	} else if (netmask == NULL) {
+		snprintf(str, STR_MAX, "/sbin/ifconfig %s %s", 
+			 interface, address);
+	} else {
+		snprintf(str, STR_MAX, "/sbin/ifconfig %s %s netmask %s", 
+			 interface, address, netmask);
+	}
+
+        if (run_cmd(str) != 0) {
+		fprintf(stderr, "%s: Failed to configure %s\n",
+			exec_name, interface);
+                close(sd);
+                return -1;
+        }
+
+	if (bridge != NULL) {
+		/* Check to see if bridge is alread up */
+		snprintf(str, STR_MAX, "/sbin/ifconfig %s", bridge);
+		if (run_cmd(str) == 0) {
+			/* bridge is already up */
+			if (bridged_if != NULL) {
+				fprintf(stderr, "%s: Warning: %s already exists, so %s was not added.\n",
+					exec_name, bridge, bridged_if);
+			}
+		} else {
+			snprintf(str, STR_MAX, "/sbin/ifconfig %s create", bridge);
+			if (run_cmd(str) != 0) {
+				fprintf(stderr, "%s: Failed to create %s\n",
+					exec_name, bridge);
+				close(sd);
+				return -1;
+			}
+			remove_bridge = 1;
+
+			snprintf(str, STR_MAX, "/sbin/ifconfig %s up", bridge);
+			if (run_cmd(str) != 0) {
+				fprintf(stderr, "%s: Failed to open %s\n",
+					exec_name, bridge);
+				close(sd);
+				return -1;
+			}
+
+			if (bridged_if != NULL) {
+				snprintf(str, STR_MAX, "/sbin/ifconfig %s addm %s", 
+					 bridge, bridged_if);
+				if (run_cmd(str) != 0) {
+					fprintf(stderr, "%s: Failed to add %s to %s\n",
+						exec_name, bridged_if, bridge);
+					close(sd);
+					return -1;
+				}
+			}
+			
+			snprintf(str, STR_MAX, "/sbin/ifconfig %s addm %s", 
+				 bridge, interface);
+			if (run_cmd(str) != 0) {
+				fprintf(stderr, "%s: Failed to add %s to %s\n",
+					exec_name, interface, bridge);
+				close(sd);
+				return -1;
+			}
+		}
+	}
+
+        return sd;
+}
+ 
+static int open_bpf(char *ifname)
+{
+	u_int blen = 0;
+	struct ifreq ifreq;
+	u_int arg;
+
+	int sd = open("/dev/bpf2", O_RDWR);
+
+	if (sd < 0) {
+		return -1;
+	}
+
+	if (ioctl(sd, BIOCGBLEN, &blen) < 0) {
+		close(sd);
+		return -2;
+	}
+
+	bzero(&ifreq, sizeof(ifreq));
+	strncpy(ifreq.ifr_name, ifname, IFNAMSIZ);
+
+	arg = 0;
+	if (ioctl(sd, BIOCSETIF, &ifreq) < 0) {
+		close(sd);
+		return -3;
+	}
+
+	arg = 0;
+	if (ioctl(sd, BIOCSSEESENT, &arg) < 0) {
+		close(sd);
+		return -4;
+	}
+
+	arg = 1;
+	if (ioctl(sd, BIOCPROMISC, &arg) < 0) {
+		close(sd);
+		return -5;
+	}
+
+	arg = 1;
+	if (ioctl(sd, BIOCIMMEDIATE, &arg) < 0) {
+		close(sd);
+		return -6;
+	}
+
+	return sd;
+}
+
+static int run_cmd(const char *cmd) {
+	char cmd_buffer[STR_MAX] = {0};
+	char *argv[MAX_ARGV + 1] = {0};
+	int i;
+	pid_t pid, waitpid;
+	int status = 0;
+
+	/* Collect arguments */
+	strncpy(cmd_buffer, cmd, STR_MAX-1);
+
+	argv[0] = strtok(cmd_buffer, " ");
+	for (i=1; i<MAX_ARGV; ++i) {
+		argv[i] = strtok(NULL, " ");
+		if (argv[i] == NULL) {
+			break;
+		}
+	}
+
+	/* Run sub process */
+	pid = fork();
+	if (pid == 0) {
+
+		/* Child process */
+		fclose(stdout);
+		fclose(stderr);
+
+		if (execve(argv[0], argv, NULL) < 0) {
+			perror("execve");
+			return -1;
+		}
+	} else {
+		/* Wait for child to exit */
+		waitpid = wait(&status);
+		if (waitpid < 0) {
+			perror("wait");
+			return -1;
+		}
+
+		if (status != 0) {
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+static void handler(int signum) {
+        do_exit();
+        exit(1);
+}
+
+static int install_signal_handlers() {
+        struct sigaction act = {0};
+
+        act.sa_handler = handler;
+        sigemptyset(&act.sa_mask);
+
+        if (sigaction(SIGINT, &act, NULL) != 0) {
+                return -1;
+        }
+
+
+        if (sigaction(SIGHUP, &act, NULL) != 0) {
+                return -1;
+        }
+
+
+        if (sigaction(SIGTERM, &act, NULL) != 0) {
+                return -1;
+        }
+
+        return 0;
+}
+
+static void do_exit() {
+        if (remove_bridge) {
+                run_cmd("/sbin/ifconfig bridge0 destroy");
+        }
+}
diff --git a/BasiliskII/src/MacOSX/runtool.c b/BasiliskII/src/MacOSX/runtool.c
new file mode 100644
index 00000000..77c38a43
--- /dev/null
+++ b/BasiliskII/src/MacOSX/runtool.c
@@ -0,0 +1,136 @@
+/*
+ *  runtool.m - Run an external program as root for networking
+ *  Copyright (C) 2010, Daniel Sumorok
+ *
+ *  Basilisk II (C) 1997-2008 Christian Bauer
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <stdio.h>
+#include <string.h>
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <net/if_dl.h>
+#include <ifaddrs.h>
+#include <errno.h>
+
+#include <unistd.h>
+
+#include <net/if.h>
+#include <sys/time.h>
+#include <sys/ioctl.h>
+#include <net/bpf.h>
+#include <fcntl.h>
+
+#include <strings.h>
+
+#include <Carbon/Carbon.h>
+
+FILE * run_tool(const char *if_name, const char *tool_name);
+
+FILE * run_tool(const char *if_name, const char *tool_name)
+{
+	OSStatus auth_status;
+	FILE *fp = NULL;
+	char *args[] = {NULL, NULL, NULL};
+	int ret;
+	char path_buffer[256];
+	AuthorizationFlags auth_flags;
+	AuthorizationRef auth_ref;
+	AuthorizationItem auth_items[1];
+	AuthorizationRights auth_rights;
+	CFBundleRef bundle_ref;
+	CFURLRef url_ref;
+	CFStringRef path_str;
+	CFStringRef tool_name_str;
+	char c;
+
+	bundle_ref = CFBundleGetMainBundle();
+	if(bundle_ref == NULL) {
+		return NULL;
+	}
+
+	tool_name_str = CFStringCreateWithCString(NULL, tool_name,
+						  kCFStringEncodingUTF8);
+
+	url_ref = CFBundleCopyResourceURL(bundle_ref, tool_name_str,
+					 NULL, NULL);
+	CFRelease(tool_name_str);
+
+	if(url_ref == NULL) {
+		return NULL;
+	}
+
+	path_str = CFURLCopyFileSystemPath(url_ref, kCFURLPOSIXPathStyle);
+	CFRelease(url_ref);
+
+	if(path_str == NULL) {
+		return NULL;
+	}
+
+	if(!CFStringGetCString(path_str, path_buffer, sizeof(path_buffer),
+			       kCFStringEncodingUTF8)) {
+		CFRelease(path_str);
+		return NULL;
+	}
+	CFRelease(path_str);
+
+	args[0] = (char *)tool_name;
+	args[1] = (char *)if_name;
+  
+	auth_flags = kAuthorizationFlagExtendRights |
+		kAuthorizationFlagInteractionAllowed |
+		kAuthorizationFlagPreAuthorize;
+ 
+	auth_items[0].name = "system.privilege.admin";
+	auth_items[0].valueLength = 0;
+	auth_items[0].value = NULL;
+	auth_items[0].flags = 0;
+
+	auth_rights.count = sizeof (auth_items) / sizeof (auth_items[0]);
+	auth_rights.items = auth_items;
+  
+	auth_status = AuthorizationCreate(&auth_rights,
+					  kAuthorizationEmptyEnvironment,
+					  auth_flags,
+					  &auth_ref);
+  
+	if (auth_status != errAuthorizationSuccess) {
+		fprintf(stderr, "%s: AuthorizationCreate() failed.\n",
+			__func__);
+		return NULL;
+	}
+
+	auth_status = AuthorizationExecuteWithPrivileges(auth_ref,
+							 path_buffer,
+							 kAuthorizationFlagDefaults,
+							 args + 1,
+							 &fp);
+
+	if (auth_status != errAuthorizationSuccess) {
+		fprintf(stderr, "%s: AuthorizationExecWithPrivileges() failed.\n", 
+			__func__);
+		return NULL;
+	}
+
+	if(fread(&c, 1, 1, fp) != 1) {
+	  fclose(fp);
+	  return NULL;
+	}
+
+	return fp;
+}
diff --git a/BasiliskII/src/Unix/Linux/etherhelpertool.c b/BasiliskII/src/Unix/Linux/etherhelpertool.c
new file mode 100644
index 00000000..5d6117bc
--- /dev/null
+++ b/BasiliskII/src/Unix/Linux/etherhelpertool.c
@@ -0,0 +1,506 @@
+/*
+ *  etherhelpertool.c - Reads and writes raw ethernet packets usng bpf
+ *  interface.
+ *
+ *  Copyright (C) 2010, Daniel Sumorok
+ *
+ *  Basilisk II (C) 1997-2008 Christian Bauer
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <stdio.h>
+#include <string.h>
+
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <ifaddrs.h>
+#include <errno.h>
+#include <sys/select.h>
+
+#include <unistd.h>
+#include <stdlib.h>
+
+#include <net/if.h>
+#include <sys/time.h>
+#include <sys/ioctl.h>
+#include <sys/socket.h>
+#include <netpacket/packet.h>
+#include <net/ethernet.h>
+#include <fcntl.h>
+#include <signal.h>
+
+#include <linux/if_tun.h>
+
+#include <strings.h>
+
+#define STR_MAX 256
+#define MAX_ARGV 10
+
+static int remove_bridge = 0;
+static char bridge_name[STR_MAX];
+static const char *exec_name = "etherhelpertool";
+
+static int main_loop(int sd, int use_bpf);
+static int open_tap(char *ifname);
+static int run_cmd(const char *cmd);
+static void handler(int signum);
+static int install_signal_handlers(void);
+static void do_exit(void);
+static int open_bpf(char *ifname);
+
+int main(int argc, char **argv)
+{
+	char *if_name;
+	int ret = 255;
+	int sd = -1;
+        int tapNum;
+        int use_bpf;
+
+	if (argc != 2) {
+		return 255;
+	}
+	
+	if_name = argv[1];
+
+        do {
+		if (strncmp(if_name, "tap", 3) == 0) {
+                        sd = open_tap(if_name);
+                        use_bpf = 0;
+                } else {
+                        sd = open_bpf(if_name);
+                        use_bpf = 1;
+                }
+
+                if (sd < 0) {
+			fprintf(stderr, "%s: open device failed.\n",
+				exec_name);
+                        ret = 253;
+                        break;
+                }
+
+                if (install_signal_handlers() != 0) {
+			fprintf(stderr, 
+				"%s: failed to install signal handers.\n",
+				exec_name);
+                        ret = 252;
+                        break;
+                }
+
+                ret = main_loop(sd, use_bpf);
+                close(sd);
+        } while (0);
+
+        do_exit();
+
+	return ret;
+}
+
+static int main_loop(int sd, int use_bpf)
+{
+	fd_set readSet;
+	char *outgoing, *incoming;
+	unsigned short *out_len;
+	unsigned short *in_len;
+	int in_index, out_index;
+	u_int blen = 0;
+	int ret;
+	int fret = 0;
+	int pkt_len;
+	int frame_len;
+	int pad;
+        char c = 0;
+
+	blen = 4096;
+
+	incoming = malloc(blen);
+	if (incoming == NULL) {
+		fprintf(stderr, 
+			"%s: malloc() failed.\n",
+			exec_name);
+		return -2;
+	}
+
+	outgoing = malloc(blen);
+	if (outgoing == NULL) {
+		free(outgoing);
+		fprintf(stderr, 
+			"%s: malloc() failed.\n",
+			exec_name);
+		return -3;
+	}
+
+	in_index = 0;
+	out_index = 0;
+
+	out_len = (unsigned short *)outgoing;
+
+        /* Let our parent know we are ready for business. */
+        if(write(0, &c, 1) != 1) {
+	  fprintf(stderr, "%s: Failed to notify main application: %s\n",
+		  __func__, strerror(errno));
+	}
+
+	while (1) {
+		int i;
+		FD_ZERO(&readSet);
+		FD_SET(0, &readSet);
+		FD_SET(sd, &readSet);
+
+		ret = select(sd + 1, &readSet, NULL, NULL, NULL);
+		if (ret < 0) {
+			fprintf(stderr, 
+				"%s: select() failed.\n",
+				exec_name);
+			fret = -4;
+			break;
+		}
+
+		if (FD_ISSET(0, &readSet)) {
+			if (out_index < 2) {
+				ret = read(0, outgoing + out_index, 2-out_index);
+			} else {
+				ret = read(0, outgoing + out_index, *out_len - out_index + 2);
+			}
+
+			if (ret < 1) {
+				if(ret < 0) {
+					fprintf(stderr, 
+						"%s: read() failed.\n",
+						exec_name);
+				}
+				fret = -5;
+				break;
+			}
+
+			out_index += ret;
+
+			if (out_index > 1) {
+				if ((*out_len + 2) > blen) {
+					fret = -6;
+					break;
+				}
+
+				if (out_index == (*out_len + 2)) {
+					if(use_bpf) {
+						ret = write(sd, out_len + 1, *out_len);
+						if (ret != *out_len) {
+							fprintf(stderr,
+								"%s: write() failed.\n",
+								exec_name);
+							fret = -7;
+							break;
+						}
+					} else {
+						ret = write(sd, out_len + 1, *out_len);
+						if (ret != *out_len) {
+							fprintf(stderr,
+								"%s: write() failed.\n",
+								exec_name);
+							fret = -7;
+							break;
+						}
+					}
+
+					out_index = 0;
+				}
+			}
+
+		}
+
+		if (FD_ISSET(sd, &readSet)) {
+			in_len = (unsigned short *)incoming;
+
+			pkt_len = read(sd, in_len + 1, blen-2);
+			if (pkt_len < 14) {
+				fprintf(stderr,
+					"%s: read() returned %d.\n",
+					exec_name, pkt_len);
+				fret = -8;
+				break;
+			}
+                        *in_len = pkt_len;
+
+                        if (write(0, in_len, pkt_len + 2) < (pkt_len + 2)) {
+				fprintf(stderr,
+					"%s: write() failed\n",
+					exec_name);
+                                fret = -10;
+                                break;
+                        }
+                }
+	}
+
+	free(incoming);
+	free(outgoing);
+
+	return fret;
+}
+
+
+static int open_tap(char *ifname)
+{
+        char str[STR_MAX] = {0};
+        char ifstr[STR_MAX] = {0};
+	char *interface;
+	char *address = NULL;
+	char *netmask = NULL;
+	char *bridge = NULL;
+	char *bridged_if = NULL;
+        int sd;
+	struct ifreq ifr = {0};
+
+	snprintf(ifstr, STR_MAX, "%s", ifname);
+	interface = strtok(ifstr, "/");
+	bridge = strtok(NULL, "/");
+	if (bridge != NULL) {
+		bridged_if = strtok(NULL, "/");
+	}
+	interface = strtok(ifstr, ":");
+
+	address = strtok(NULL, ":");
+
+	if (address != NULL) {
+		netmask = strtok(NULL, ":");
+	}
+
+        sd = open("/dev/net/tun", O_RDWR);
+        if (sd < 0) {
+		fprintf(stderr, "%s: Failed to open %s\n",
+			exec_name, interface);
+                return -1;
+        }
+
+        snprintf(str, STR_MAX, "/dev/%s", interface);
+        ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
+        strncpy(ifr.ifr_name, interface, IFNAMSIZ);
+
+        if(ioctl(sd, TUNSETIFF, (void *)&ifr) != 0) {
+                fprintf(stderr, "%s: ioctl(TUNSETIFF): %s\n",
+                        __func__, strerror(errno));
+                close(sd);
+                return -1;
+        }
+
+        if (address == NULL) {
+                snprintf(str, STR_MAX, "/sbin/ifconfig %s up", interface);
+        } else if (netmask == NULL) {
+                snprintf(str, STR_MAX, "/sbin/ifconfig %s %s",
+                         interface, address);
+        } else {
+                snprintf(str, STR_MAX, "/sbin/ifconfig %s %s netmask %s",
+                         interface, address, netmask);
+        }
+
+        if (run_cmd(str) != 0) {
+		fprintf(stderr, "%s: Failed to configure %s\n",
+			exec_name, interface);
+                close(sd);
+                return -1;
+        }
+
+	if (bridge != NULL) {
+		/* Check to see if bridge is alread up */
+		snprintf(str, STR_MAX, "/sbin/ifconfig %s", bridge);
+		if (run_cmd(str) == 0) {
+			/* bridge is already up */
+			if (bridged_if != NULL) {
+				fprintf(stderr, "%s: Warning: %s already exists, so %s was not added.\n",
+					exec_name, bridge, bridged_if);
+			}
+		} else {
+			snprintf(str, STR_MAX, "/sbin/brctl addbr %s", bridge);
+			if (run_cmd(str) != 0) {
+				fprintf(stderr, "%s: Failed to create %s\n",
+					exec_name, bridge);
+				close(sd);
+				return -1;
+			}
+			remove_bridge = 1;
+
+			strncpy(bridge_name, bridge, STR_MAX);
+
+			snprintf(str, STR_MAX, "/sbin/ifconfig %s up", bridge);
+			if (run_cmd(str) != 0) {
+				fprintf(stderr, "%s: Failed to open %s\n",
+					exec_name, bridge);
+				close(sd);
+				return -1;
+			}
+
+			if (bridged_if != NULL) {
+				snprintf(str, STR_MAX, "/sbin/brctl addif %s %s",
+					 bridge, bridged_if);
+				if (run_cmd(str) != 0) {
+					fprintf(stderr, "%s: Failed to add %s to %s\n",
+						exec_name, bridged_if, bridge);
+					close(sd);
+					return -1;
+				}
+			}
+
+			snprintf(str, STR_MAX, "/sbin/brctl addif %s %s",
+				 bridge, interface);
+			if (run_cmd(str) != 0) {
+				fprintf(stderr, "%s: Failed to add %s to %s\n",
+					exec_name, interface, bridge);
+				close(sd);
+				return -1;
+			}
+		}
+	}
+
+        return sd;
+}
+
+static int run_cmd(const char *cmd) {
+	char cmd_buffer[STR_MAX] = {0};
+	char *argv[MAX_ARGV + 1] = {0};
+	int i;
+	pid_t pid, waitpid;
+	int status = 0;
+
+	/* Collect arguments */
+	strncpy(cmd_buffer, cmd, STR_MAX-1);
+
+	argv[0] = strtok(cmd_buffer, " ");
+	for (i=1; i<MAX_ARGV; ++i) {
+		argv[i] = strtok(NULL, " ");
+		if (argv[i] == NULL) {
+			break;
+		}
+	}
+
+	/* Run sub process */
+	pid = fork();
+	if (pid == 0) {
+
+		/* Child process */
+		fclose(stdout);
+		fclose(stderr);
+
+		if (execve(argv[0], argv, NULL) < 0) {
+			perror("execve");
+			return -1;
+		}
+	} else {
+		/* Wait for child to exit */
+		waitpid = wait(&status);
+		if (waitpid < 0) {
+			perror("wait");
+			return -1;
+		}
+
+		if (status != 0) {
+			return -1;
+		}
+	}
+
+	return 0;
+}
+
+static void handler(int signum) {
+        do_exit();
+        exit(1);
+}
+
+static int install_signal_handlers() {
+        struct sigaction act = {0};
+
+        act.sa_handler = handler;
+        sigemptyset(&act.sa_mask);
+
+        if (sigaction(SIGINT, &act, NULL) != 0) {
+                return -1;
+        }
+
+
+        if (sigaction(SIGHUP, &act, NULL) != 0) {
+                return -1;
+        }
+
+
+        if (sigaction(SIGTERM, &act, NULL) != 0) {
+                return -1;
+        }
+
+        return 0;
+}
+
+static void do_exit() {
+	char cmd[STR_MAX];
+
+        if (remove_bridge) {
+		snprintf(cmd, STR_MAX, "/sbin/ifconfig %s down",
+			 bridge_name);
+
+                if(run_cmd(cmd) != 0) {
+			fprintf(stderr, "Failed to bring bridge down\n");
+		}
+
+		snprintf(cmd, STR_MAX, "/sbin/brctl delbr %s",
+			 bridge_name);
+
+                if(run_cmd(cmd) != 0) {
+			fprintf(stderr, "Failed to destroy bridge\n");
+		}
+        }
+}
+
+static int open_bpf(char *ifname)
+{
+	int sd;
+	struct sockaddr_ll sockaddr = {0};
+	struct ifreq ifreq = {0};
+	struct packet_mreq pmreq = {0};
+	socklen_t socklen = sizeof(struct packet_mreq);
+
+	sd = socket(AF_PACKET, SOCK_RAW, htons(ETH_P_ALL));
+	if(sd < 0) {
+		perror("socket");
+		return -1;
+	}
+
+	strncpy(ifreq.ifr_name, ifname, IFNAMSIZ);
+	if(ioctl(sd, SIOCGIFINDEX, &ifreq) != 0) {
+		fprintf(stderr, "%s: ioctl(SIOCGIFINDEX): %s\n",
+			__func__, strerror(errno));
+		close(sd);
+		return -1;
+	}
+
+	pmreq.mr_ifindex =  ifreq.ifr_ifindex;
+	pmreq.mr_type = PACKET_MR_PROMISC;
+	if(setsockopt(sd, SOL_PACKET, PACKET_ADD_MEMBERSHIP,
+		      &pmreq, socklen) != 0) {
+		fprintf(stderr, "%s: setsockopt() failed: %s\n",
+			__func__, strerror(errno));
+		close(sd);
+		return -1;
+	}
+
+	sockaddr.sll_family = AF_PACKET;
+	sockaddr.sll_ifindex = ifreq.ifr_ifindex;
+	sockaddr.sll_protocol = htons(ETH_P_ALL);
+	if(bind(sd, (struct sockaddr *)&sockaddr,
+		sizeof(struct sockaddr_ll)) != 0) {
+		fprintf(stderr, "%s: bind failed: %s\n",
+			__func__, strerror(errno));
+		close(sd);
+		return -1;
+	}
+
+	return sd;
+}
diff --git a/BasiliskII/src/Unix/Linux/runtool.c b/BasiliskII/src/Unix/Linux/runtool.c
new file mode 100644
index 00000000..75eeaf9f
--- /dev/null
+++ b/BasiliskII/src/Unix/Linux/runtool.c
@@ -0,0 +1,58 @@
+#include <string.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <errno.h>
+
+#define STR_MAX 1024
+#define MAX_ARGV 10
+
+FILE * run_tool(const char *if_name, const char *tool_name) {
+	char cmd_buffer[STR_MAX] = {0};
+	char * const argv[3] = {NULL, NULL, NULL};
+	int i;
+	pid_t pid, waitpid;
+	int status = 0;
+	int fds[2];
+	char c;
+
+	if(socketpair(PF_LOCAL, SOCK_STREAM, 0, fds) != 0) {
+		fprintf(stderr, "%s: socketpair() failed: %s\n",
+			__func__, strerror(errno));
+		return NULL;
+	}
+
+	((const char**)argv)[0] = tool_name;
+	((const char**)argv)[1] = if_name;
+
+	/* Run sub process */
+	pid = fork();
+	if (pid == 0) {
+		/* Child process */
+		fclose(stdout);
+		fclose(stdin);
+		dup2(fds[0], 0);
+		close(fds[1]);
+		close(fds[0]);
+
+		if (execve(tool_name, argv, NULL) < 0) {
+			perror("execve");
+			exit(1);
+		}
+	}
+
+
+	close(fds[0]);
+
+	if(read(fds[1], &c, 1) < 1) {
+	  close(fds[1]);
+	  return NULL;
+	}
+
+	return fdopen(fds[1], "rw");
+}
diff --git a/BasiliskII/src/Unix/ether_unix.cpp b/BasiliskII/src/Unix/ether_unix.cpp
index a9ca33ce..73cba7c7 100644
--- a/BasiliskII/src/Unix/ether_unix.cpp
+++ b/BasiliskII/src/Unix/ether_unix.cpp
@@ -41,6 +41,21 @@
 #endif
 #include <sys/ioctl.h>
 #include <sys/socket.h>
+
+#ifdef ENABLE_MACOSX_ETHERHELPER
+
+#ifdef __APPLE__
+#include <net/if_dl.h>
+#endif
+
+#ifdef __linux__
+#include <linux/if_packet.h>
+#endif
+
+#include <sys/socket.h>
+#include <ifaddrs.h>
+#endif
+
 #include <sys/wait.h>
 #include <netinet/in.h>
 #include <pthread.h>
@@ -49,6 +64,7 @@
 #include <stdio.h>
 #include <signal.h>
 #include <map>
+#include <string>
 
 #if defined(__FreeBSD__) || defined(sgi) || (defined(__APPLE__) && defined(__MACH__))
 #include <net/if.h>
@@ -93,9 +109,17 @@ enum {
 	NET_IF_SHEEPNET,
 	NET_IF_ETHERTAP,
 	NET_IF_TUNTAP,
-	NET_IF_SLIRP
+	NET_IF_SLIRP,
+	NET_IF_ETHERHELPER
 };
 
+
+#ifdef ENABLE_MACOSX_ETHERHELPER
+extern "C" {
+	extern FILE * run_tool(const char *if_name, const char *tool_name);
+}
+#endif
+
 // Constants
 #if ENABLE_TUNTAP
 static const char ETHERCONFIG_FILE_NAME[] = DATADIR "/tunconfig";
@@ -122,6 +146,11 @@ static uint8 ether_addr[6];					// Our Ethernet address
 const bool ether_driver_opened = true;		// Flag: is the MacOS driver opened?
 #endif
 
+
+#ifdef ENABLE_MACOSX_ETHERHELPER
+static uint8 packet_buffer[2048];
+#endif
+
 // Attached network protocols, maps protocol type to MacOS handler address
 static map<uint16, uint32> net_protocols;
 
@@ -135,6 +164,11 @@ static void ether_do_interrupt(void);
 static void slirp_add_redirs();
 static int slirp_add_redir(const char *redir_str);
 
+#ifdef ENABLE_MACOSX_ETHERHELPER
+static int get_mac_address(const char* dev, unsigned char *addr);
+static bool open_ether_helper(const std::string &if_name);
+static int read_packet(void);
+#endif
 
 /*
  *  Start packet reception thread
@@ -235,6 +269,9 @@ bool ether_init(void)
 
 	// Do nothing if no Ethernet device specified
 	const char *name = PrefsFindString("ether");
+#ifdef ENABLE_MACOSX_ETHERHELPER
+	std::string slave_dev;
+#endif
 	if (name == NULL)
 		return false;
 
@@ -249,6 +286,10 @@ bool ether_init(void)
 #ifdef HAVE_SLIRP
 	else if (strcmp(name, "slirp") == 0)
 		net_if_type = NET_IF_SLIRP;
+#endif
+#ifdef ENABLE_MACOSX_ETHERHELPER
+	else if (strncmp(name, "etherhelper", 10) == 0)
+		 net_if_type = NET_IF_ETHERHELPER;
 #endif
 	else
 		net_if_type = NET_IF_SHEEPNET;
@@ -300,6 +341,25 @@ bool ether_init(void)
 	case NET_IF_SHEEPNET:
 		strcpy(dev_name, "/dev/sheep_net");
 		break;
+#ifdef ENABLE_MACOSX_ETHERHELPER
+	case NET_IF_ETHERHELPER: {
+		std::string device(name);
+		size_t pos;
+
+		pos = device.find('/');
+		if(pos != device.npos) {
+			slave_dev = device.substr(pos + 1);
+		}
+
+		if(slave_dev.size() == 0) {
+			WarningAlert("No network device specified.");
+			return false;
+		}
+
+		return open_ether_helper(slave_dev);
+	}
+
+#endif
 	}
 	if (net_if_type != NET_IF_SLIRP) {
 		fd = open(dev_name, O_RDWR);
@@ -750,6 +810,21 @@ static int16 ether_do_write(uint32 arg)
 		write(slirp_input_fd, packet, len);
 		return noErr;
 	} else
+#endif
+#ifdef ENABLE_MACOSX_ETHERHELPER
+	if (net_if_type == NET_IF_ETHERHELPER) {
+		unsigned short pkt_len;
+
+		pkt_len = len;
+		if (write(fd, &pkt_len, 2) < 2) {
+			return excessCollsns;
+		}
+
+		if (write(fd, packet, len) < len) {
+			return excessCollsns;
+		}
+		return noErr;
+	} else
 #endif
 	if (write(fd, packet, len) < 0) {
 		D(bug("WARNING: Couldn't transmit packet\n"));
@@ -884,6 +959,13 @@ static void *receive_func(void *arg)
 		if (res <= 0)
 			break;
 
+#ifdef ENABLE_MACOSX_ETHERHELPER
+		if (net_if_type == NET_IF_ETHERHELPER) {
+			if (read_packet() < 1) {
+				break;
+			}
+		}
+#endif
 		if (ether_driver_opened) {
 			// Trigger Ethernet interrupt
 			D(bug(" packet received, triggering Ethernet interrupt\n"));
@@ -923,6 +1005,18 @@ void ether_do_interrupt(void)
 			ether_udp_read(packet, length, &from);
 
 		} else
+#endif
+#ifdef ENABLE_MACOSX_ETHERHELPER
+		if (net_if_type == NET_IF_ETHERHELPER) {
+			unsigned short *pkt_len;
+			uint32 p = packet;
+
+			pkt_len = (unsigned short *)packet_buffer;
+			length = *pkt_len;
+			memcpy(Mac2HostAddr(packet), pkt_len + 1, length);
+			ether_dispatch_packet(p, length);
+			break;
+		} else
 #endif
 		{
 
@@ -1049,3 +1143,144 @@ static int slirp_add_redir(const char *redir_str)
 	WarningAlert(str);
 	return -1;
 }
+
+#ifdef ENABLE_MACOSX_ETHERHELPER
+static int get_mac_address(const char* dev, unsigned char *addr)
+{
+	struct ifaddrs *ifaddrs, *next;
+	int ret = -1;
+#ifdef __APPLE__
+	struct sockaddr_dl *sa;
+#endif
+
+#ifdef __linux__
+	struct sockaddr_ll *sa;
+#endif
+	if (getifaddrs(&ifaddrs) != 0) {
+		perror("getifaddrs");
+		return -1;
+	}
+
+	next = ifaddrs;
+	while (next != NULL) {
+		switch (next->ifa_addr->sa_family) {
+#ifdef __APPLE__
+		case AF_LINK:
+			if (!strcmp(dev, next->ifa_name)) {
+				sa = (struct sockaddr_dl *)next->ifa_addr;
+				memcpy(addr, LLADDR(sa), 6);
+				ret = 0;
+			}
+			break;
+#endif
+
+#ifdef __linux__
+		case AF_PACKET:
+			if (!strcmp(dev, next->ifa_name)) {
+				sa = (struct sockaddr_ll *)next->ifa_addr;
+				memcpy(addr, sa->sll_addr, 6);
+				ret = 0;
+			}
+			break;
+#endif
+		default:
+			break;
+		}
+		next = next->ifa_next;
+	}
+
+	freeifaddrs(ifaddrs);
+
+	return ret;
+}
+
+static bool open_ether_helper(const std::string &if_name)
+{
+	FILE *fp;
+	char str[64];
+	std::string dev_name;
+	size_t pos;
+
+	fp = run_tool(if_name.c_str(), "etherhelpertool");
+	if (fp == NULL) {
+		snprintf(str, sizeof(str), "Unable to run ether helper helper tool.");
+		WarningAlert(str);
+		return false;
+	}
+
+	pos = if_name.find('/');
+	dev_name = if_name;
+	if(pos != if_name.npos) {
+		dev_name.erase(pos);
+	}
+
+	if(strncmp(if_name.c_str(), "tap", 3) != 0) {
+		if (get_mac_address(dev_name.c_str(), ether_addr) != 0) {
+			snprintf(str, sizeof(str), "Unable to find interface %s.",
+				 dev_name.c_str());
+			WarningAlert(str);
+			return false;
+		}
+	} else {
+		/* There is something special about this address. */
+		pid_t p = getpid();
+		ether_addr[0] = 0xfe;
+		ether_addr[1] = 0xfd;
+		ether_addr[2] = p >> 24;
+		ether_addr[3] = p >> 16;
+		ether_addr[4] = p >> 8;
+		ether_addr[5] = p;
+	}
+
+	fd = dup(fileno(fp));
+	fclose(fp);
+
+	if (start_thread() == false) {
+		close(fd);
+		fd = -1;
+		return false;
+	}
+
+	return true;
+}
+
+static int read_packet()
+{
+	int index;
+	unsigned short *pkt_len;
+	int ret = -1;
+
+	pkt_len = (unsigned short *)packet_buffer;
+
+	index = 0;
+	while (1) {
+		if (index < 2) {
+			ret = read(fd, packet_buffer + index, 2 - index);
+		} else {
+			ret = read(fd, packet_buffer + index, *pkt_len - index + 2);
+		}
+
+		if (ret < 1) {
+			fprintf(stderr, "%s: read() returned %d.\n", __func__, ret);
+			break;
+		}
+
+		index += ret;
+
+		if (index > 1) {
+			if (*pkt_len > (sizeof(packet_buffer) + 2)) {
+				fprintf(stderr, "%s: pkt_len (%d) too large.\n", __func__, *pkt_len);
+				break;
+			}
+
+			if (index == (*pkt_len + 2)) {
+				ret = *pkt_len;
+				break;
+			}
+		}
+	}
+
+	return ret;
+}
+
+#endif