diff --git a/sim_ether.c b/sim_ether.c
index e1013bcb..73863258 100644
--- a/sim_ether.c
+++ b/sim_ether.c
@@ -1783,9 +1783,9 @@ static void eth_get_nic_hw_addr(ETH_DEV* dev, const char *devname, int set_on)
         NULL};
     const char *patterns[] = {
         "ip link show %.*s 2>/dev/null | grep [0-9a-fA-F][0-9a-fA-F]:[0-9a-fA-F][0-9a-fA-F]:[0-9a-fA-F][0-9a-fA-F]:[0-9a-fA-F][0-9a-fA-F]:[0-9a-fA-F][0-9a-fA-F]:[0-9a-fA-F][0-9a-fA-F]",
-        "ip link show %.*s 2>/dev/null | egrep [0-9a-fA-F]?[0-9a-fA-F]:[0-9a-fA-F]?[0-9a-fA-F]:[0-9a-fA-F]?[0-9a-fA-F]:[0-9a-fA-F]?[0-9a-fA-F]:[0-9a-fA-F]?[0-9a-fA-F]:[0-9a-fA-F]?[0-9a-fA-F]",
+        "ip link show %.*s 2>/dev/null | grep -E [0-9a-fA-F]?[0-9a-fA-F]:[0-9a-fA-F]?[0-9a-fA-F]:[0-9a-fA-F]?[0-9a-fA-F]:[0-9a-fA-F]?[0-9a-fA-F]:[0-9a-fA-F]?[0-9a-fA-F]:[0-9a-fA-F]?[0-9a-fA-F]",
         "ifconfig %.*s 2>/dev/null | grep [0-9a-fA-F][0-9a-fA-F]:[0-9a-fA-F][0-9a-fA-F]:[0-9a-fA-F][0-9a-fA-F]:[0-9a-fA-F][0-9a-fA-F]:[0-9a-fA-F][0-9a-fA-F]:[0-9a-fA-F][0-9a-fA-F]",
-        "ifconfig %.*s 2>/dev/null | egrep [0-9a-fA-F]?[0-9a-fA-F]:[0-9a-fA-F]?[0-9a-fA-F]:[0-9a-fA-F]?[0-9a-fA-F]:[0-9a-fA-F]?[0-9a-fA-F]:[0-9a-fA-F]?[0-9a-fA-F]:[0-9a-fA-F]?[0-9a-fA-F]",
+        "ifconfig %.*s 2>/dev/null | grep -E [0-9a-fA-F]?[0-9a-fA-F]:[0-9a-fA-F]?[0-9a-fA-F]:[0-9a-fA-F]?[0-9a-fA-F]:[0-9a-fA-F]?[0-9a-fA-F]:[0-9a-fA-F]?[0-9a-fA-F]:[0-9a-fA-F]?[0-9a-fA-F]",
         NULL};
 
     memset(command, 0, sizeof(command));