diff --git a/address.h b/address.h
index 7578f91..35ef05f 100644
--- a/address.h
+++ b/address.h
@@ -24,6 +24,7 @@
 #include <netpacket/packet.h>
 #include <sys/socket.h>
 #include <sys/un.h>
+#include <net/if_arp.h>
 
 struct address {
 	socklen_t len;
diff --git a/ether.h b/ether.h
index ce3d663..8ec9669 100644
--- a/ether.h
+++ b/ether.h
@@ -22,7 +22,13 @@
 
 #include <stdint.h>
 
-#define MAC_LEN 6
+#define EUI48 6
+#define EUI64 8
+
+#define MAC_LEN  EUI48
+#define GUID_LEN EUI64
+
+#define GUID_OFFSET 36
 
 typedef uint8_t eth_addr[MAC_LEN];
 
diff --git a/sk.c b/sk.c
index 63ec206..0cf55c5 100644
--- a/sk.c
+++ b/sk.c
@@ -159,10 +159,55 @@ failed:
 	return -1;
 }
 
+static int sk_interface_guidaddr(const char *name, unsigned char *guid)
+{
+	char file_name[64], buf[64], addr[8];
+	FILE *f;
+	char *err;
+	int res;
+
+	snprintf(file_name, sizeof buf, "/sys/class/net/%s/address", name);
+	f = fopen(file_name, "r");
+	if (!f) {
+		pr_err("failed to open %s: %m", buf);
+		return -1;
+	}
+
+	/* Set the file position to the beginning of the GUID */
+	res = fseek(f, GUID_OFFSET, SEEK_SET);
+	if (res) {
+		pr_err("fseek failed: %m");
+		goto error;
+	}
+
+	err = fgets(buf, sizeof buf, f);
+	if (err == NULL) {
+		pr_err("fseek failed: %m");
+		goto error;
+	}
+
+	res = sscanf(buf, "%hhx:%hhx:%hhx:%hhx:%hhx:%hhx:%hhx:%hhx",
+			   &addr[0], &addr[1], &addr[2], &addr[3],
+			   &addr[4], &addr[5], &addr[6], &addr[7]);
+	if (res != GUID_LEN) {
+		pr_err("sscanf failed: %m");
+		goto error;
+	}
+
+	memcpy(guid, addr, GUID_LEN);
+	fclose(f);
+
+	return 0;
+
+error:
+	fclose(f);
+	return -1;
+}
+
 int sk_interface_macaddr(const char *name, struct address *mac)
 {
 	struct ifreq ifreq;
-	int err, fd;
+	int err, fd, type;
 
 	memset(&ifreq, 0, sizeof(ifreq));
 	strncpy(ifreq.ifr_name, name, sizeof(ifreq.ifr_name) - 1);
@@ -180,9 +225,23 @@ int sk_interface_macaddr(const char *name, struct address *mac)
 		return -1;
 	}
 
+	/* Get interface type */
+	type = ifreq.ifr_hwaddr.sa_family;
+	switch (type) {
+		case ARPHRD_INFINIBAND:
+			err = sk_interface_guidaddr(name, mac->sll.sll_addr);
+			if (err) {
+				pr_err("fail to get address using sysfs: %m");
+				return -1;
+			}
+			mac->sll.sll_halen = EUI64;
+			break;
+		default:
+			memcpy(mac->sll.sll_addr, &ifreq.ifr_hwaddr.sa_data, MAC_LEN);
+			mac->sll.sll_halen = EUI48;
+	}
+
 	mac->sll.sll_family = AF_PACKET;
-	mac->sll.sll_halen = MAC_LEN;
-	memcpy(mac->sll.sll_addr, &ifreq.ifr_hwaddr.sa_data, MAC_LEN);
 	mac->len = sizeof(mac->sll);
 	close(fd);
 	return 0;
diff --git a/util.c b/util.c
index 2b880ff..62f2638 100644
--- a/util.c
+++ b/util.c
@@ -135,14 +135,32 @@ int generate_clock_identity(struct ClockIdentity *ci, const char *name)
 
 	if (sk_interface_macaddr(name, &addr))
 		return -1;
-	ci->id[0] = addr.sll.sll_addr[0];
-	ci->id[1] = addr.sll.sll_addr[1];
-	ci->id[2] = addr.sll.sll_addr[2];
-	ci->id[3] = 0xFF;
-	ci->id[4] = 0xFE;
-	ci->id[5] = addr.sll.sll_addr[3];
-	ci->id[6] = addr.sll.sll_addr[4];
-	ci->id[7] = addr.sll.sll_addr[5];
+
+	switch (addr.sll.sll_halen) {
+		case EUI48:
+			ci->id[0] = addr.sll.sll_addr[0];
+			ci->id[1] = addr.sll.sll_addr[1];
+			ci->id[2] = addr.sll.sll_addr[2];
+			ci->id[3] = 0xFF;
+			ci->id[4] = 0xFE;
+			ci->id[5] = addr.sll.sll_addr[3];
+			ci->id[6] = addr.sll.sll_addr[4];
+			ci->id[7] = addr.sll.sll_addr[5];
+			break;
+		case EUI64:
+			ci->id[0] = addr.sll.sll_addr[0];
+			ci->id[1] = addr.sll.sll_addr[1];
+			ci->id[2] = addr.sll.sll_addr[2];
+			ci->id[3] = addr.sll.sll_addr[3];
+			ci->id[4] = addr.sll.sll_addr[4];
+			ci->id[5] = addr.sll.sll_addr[5];
+			ci->id[6] = addr.sll.sll_addr[6];
+			ci->id[7] = addr.sll.sll_addr[7];
+			break;
+		default:
+			return -1;
+	}
+
 	return 0;
 }