diff --git a/aos/common/Configuration.cpp b/aos/common/Configuration.cpp
new file mode 100644
index 0000000..e0b56ea
--- /dev/null
+++ b/aos/common/Configuration.cpp
@@ -0,0 +1,150 @@
+#include "Configuration.h"
+
+#include <stdio.h>
+#include <string.h>
+#include <errno.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <sys/types.h>
+#include <netinet/in.h>
+#include <arpa/inet.h>
+#ifdef __VXWORKS__
+#include <ifLib.h>
+#include <inetLib.h>
+#else
+#include <ifaddrs.h>
+#endif
+
+#include "aos/aos_core.h"
+#ifndef __VXWORKS__
+#include "aos/common/unique_malloc_ptr.h"
+#endif
+
+namespace aos {
+namespace configuration {
+
+namespace {
+
+#ifdef __VXWORKS__
+const size_t kMaxAddrLength = INET_ADDR_LEN;
+#else
+// Including the terminating '\0'.
+const size_t kMaxAddrLength = 18;
+#endif
+// Returns whether or not the current IP address is in ownIPAddress.
+bool GetOwnIPAddress();
+
+#ifdef __VXWORKS__
+// vxworks doesn't have real asprintf.......
+static inline int aos_asprintf(size_t max_len, char **strp, const char *fmt, ...) {
+  *strp = static_cast<char *>(malloc(max_len));
+  if (*strp == NULL) {
+    return -1;
+  }
+  va_list argp;
+  va_start(argp, fmt);
+  const int r = vsnprintf(*strp, max_len, fmt, argp);
+  va_end(argp);
+  if (static_cast<uintmax_t>(r) >= max_len) {
+    errno = EOVERFLOW;
+    free(*strp);
+    return -1;
+  }
+  return r;
+}
+
+// 4-slot cRIO: motfec0
+// 8-slot cRIO port 1: fec0
+// ifShow will show you all of the ones on a cRIO
+const char *const kCrioNetInterfaces[] = {"fec0", "motfec0"};
+bool GetOwnIPAddress(char *buffer, size_t bufferSize) {
+  if (bufferSize < INET_ADDR_LEN) {
+    LOG(ERROR, "bufferSize(%jd) isn't >= INET_ADDR_LEN(%jd)\n",
+        static_cast<intmax_t>(bufferSize),
+        static_cast<intmax_t>(INET_ADDR_LEN));
+    return false;
+  }
+  for (size_t i = 0;
+       i < sizeof(kCrioNetInterfaces) / sizeof(kCrioNetInterfaces[0]); ++i) {
+    if (ifAddrGet(const_cast<char *>(kCrioNetInterfaces[i]), buffer) != OK) {
+      LOG(DEBUG, "ifAddrGet(\"%s\", %p) failed with %d: %s\n",
+          kCrioNetInterfaces[i], buffer, errno, strerror(errno));
+    } else {
+      return true;
+    }
+  }
+  LOG(ERROR, "couldn't get the cRIO's IP address\n");
+  return false;
+}
+#else
+static inline int aos_asprintf(size_t, char **strp, const char *fmt, ...) {
+  va_list argp;
+  va_start(argp, fmt);
+  const int r = vasprintf(strp, fmt, argp);
+  va_end(argp);
+  return r;
+}
+
+const char *const kAtomNetInterface = "eth0";
+bool GetOwnIPAddress(char *buffer, size_t bufferSize) {
+  ifaddrs *addrs;
+  if (getifaddrs(&addrs) != 0) {
+    LOG(ERROR, "getifaddrs(%p) failed with %d: %s\n", &addrs,
+        errno, strerror(errno));
+    return false;
+  }
+  // Smart pointers don't work very well for iterating through a linked list,
+  // but it does do a very nice job of making sure that addrs gets freed.
+  unique_c_ptr<ifaddrs, freeifaddrs> addrs_deleter(addrs);
+
+  for (; addrs != NULL; addrs = addrs->ifa_next) {
+    if (addrs->ifa_addr->sa_family == AF_INET) {
+      if (strcmp(kAtomNetInterface, addrs->ifa_name) == 0) {
+        const char *ipAddress = inet_ntoa(
+            reinterpret_cast<sockaddr_in *>(addrs->ifa_addr)->sin_addr);
+        strncpy(buffer, ipAddress, bufferSize);
+        return true;
+      }
+    }
+  }
+  LOG(ERROR, "couldn't find an AF_INET interface named \"%s\"\n",
+      kAtomNetInterface);
+  return false;
+}
+#endif
+
+const char *RawIPAddress(uint8_t last_part) {
+  char ownIPAddress[kMaxAddrLength];
+  if (!GetOwnIPAddress(ownIPAddress, sizeof(ownIPAddress))) {
+    return NULL;
+  }
+  char *last_dot = strrchr(ownIPAddress, '.');
+  if (last_dot == NULL) {
+    LOG(ERROR, "can't find any '.'s in \"%s\"\n", ownIPAddress);
+    return NULL;
+  }
+  *last_dot = '\0';
+
+  char *r;
+  if (aos_asprintf(kMaxAddrLength, &r, "%s.%hhu",
+                   ownIPAddress, last_part) == -1) {
+    return NULL;
+  }
+  return r;
+}
+
+}  // namespace
+
+const char *GetIPAddress(NetworkDevice device) {
+  switch (device) {
+    case NetworkDevice::kAtom:
+      return RawIPAddress(179);
+    case NetworkDevice::kCRIO:
+      return RawIPAddress(2);
+  }
+  LOG(FATAL, "Unknown network device.");
+  return NULL;
+}
+
+}  // namespace configuration
+}  // namespace aos