diff --git a/ndhc/arp.c b/ndhc/arp.c
index ce64b20..b6689ac 100644
--- a/ndhc/arp.c
+++ b/ndhc/arp.c
@@ -485,7 +485,7 @@ void arp_success(struct client_state_t *cs)
     cs->init = 0;
     last_conflict_ts = 0;
     arp_wake_ts[AS_COLLISION_CHECK] = -1;
-    ifchange_bind(&arp_dhcp_packet);
+    ifchange_bind(cs, &arp_dhcp_packet);
     if (cs->arpPrevState == DS_RENEWING || cs->arpPrevState == DS_REBINDING) {
         arp_switch_state(cs, AS_DEFENSE);
     } else {
diff --git a/ndhc/ifchange.c b/ndhc/ifchange.c
index 92d0cb2..00cbb92 100644
--- a/ndhc/ifchange.c
+++ b/ndhc/ifchange.c
@@ -45,7 +45,6 @@
 #include "ifchange.h"
 #include "ifch_proto.h"
 
-static int cfg_deconfig; // Set if the interface has already been deconfigured.
 static struct dhcpmsg cfg_packet; // Copy of the current configuration packet.
 
 static int ifchd_cmd_u8(char *buf, size_t buflen, char *optname,
@@ -155,8 +154,9 @@ static int ifchd_cmd(char *buf, size_t buflen, uint8_t *optdata,
 }
 #undef IFCHD_SW_CMD
 
-static void pipewrite(const char *buf, size_t count)
+static void pipewrite(struct client_state_t *cs, const char *buf, size_t count)
 {
+    cs->ifchWorking = 1;
     if (safe_write(pToIfchW, buf, count) == -1) {
         log_error("pipewrite: write failed: %s", strerror(errno));
         return;
@@ -164,18 +164,18 @@ static void pipewrite(const char *buf, size_t count)
     log_line("Sent to ifchd: %s", buf);
 }
 
-void ifchange_deconfig(void)
+void ifchange_deconfig(struct client_state_t *cs)
 {
     char buf[256];
 
-    if (cfg_deconfig)
+    if (cs->ifDeconfig)
         return;
+    cs->ifDeconfig = 1;
 
     snprintf(buf, sizeof buf, "ip4:0.0.0.0,255.255.255.255;");
     log_line("Resetting %s IP configuration.", client_config.interface);
-    pipewrite(buf, strlen(buf));
+    pipewrite(cs, buf, strlen(buf));
 
-    cfg_deconfig = 1;
     memset(&cfg_packet, 0, sizeof cfg_packet);
 }
 
@@ -258,7 +258,7 @@ static size_t send_cmd(char *out, size_t olen, struct dhcpmsg *packet,
     return strlen(buf);
 }
 
-void ifchange_bind(struct dhcpmsg *packet)
+void ifchange_bind(struct client_state_t *cs, struct dhcpmsg *packet)
 {
     char buf[2048];
     int tbs = 0;
@@ -275,8 +275,8 @@ void ifchange_bind(struct dhcpmsg *packet)
     tbs |= send_cmd(buf, sizeof buf, packet, DCODE_MTU);
     tbs |= send_cmd(buf, sizeof buf, packet, DCODE_WINS);
     if (tbs)
-        pipewrite(buf, strlen(buf));
+        pipewrite(cs, buf, strlen(buf));
 
-    cfg_deconfig = 0;
+    cs->ifDeconfig = 0;
     memcpy(&cfg_packet, packet, sizeof cfg_packet);
 }
diff --git a/ndhc/ifchange.h b/ndhc/ifchange.h
index bba8039..e4b9bca 100644
--- a/ndhc/ifchange.h
+++ b/ndhc/ifchange.h
@@ -29,7 +29,7 @@
 #ifndef IFCHANGE_H_
 #define IFCHANGE_H_
 
-void ifchange_bind(struct dhcpmsg *packet);
-void ifchange_deconfig(void);
+void ifchange_bind(struct client_state_t *cs, struct dhcpmsg *packet);
+void ifchange_deconfig(struct client_state_t *cs);
 
 #endif
diff --git a/ndhc/ifchd.c b/ndhc/ifchd.c
index 308a334..15b7ba4 100644
--- a/ndhc/ifchd.c
+++ b/ndhc/ifchd.c
@@ -303,6 +303,24 @@ static void signal_dispatch(void)
     }
 }
 
+static void inform_execute(int success)
+{
+    int r;
+    char c = success ? '+' : '-';
+  retry:
+    r = safe_write(pToNdhcW, &c, sizeof c);
+    if (r == 0) {
+        // Remote end hung up.
+        exit(EXIT_SUCCESS);
+    } else if (r < 0) {
+        if (errno == EAGAIN || errno == EWOULDBLOCK)
+            goto retry;
+        log_line("%s: (%s) error writing to ifch -> ndhc pipe: %s",
+                 client_config.interface, __func__, strerror(errno));
+        exit(EXIT_FAILURE);
+    }
+}
+
 static void process_client_pipe(void)
 {
     char buf[MAX_BUF];
@@ -315,14 +333,18 @@ static void process_client_pipe(void)
     } else if (r < 0) {
         if (errno == EAGAIN || errno == EWOULDBLOCK)
             return;
-        log_line("ifch: error reading from ndhc -> ifch pipe: %s", strerror(errno));
+        log_line("%s: (%s) error reading from ndhc -> ifch pipe: %s",
+                 client_config.interface, __func__, strerror(errno));
         exit(EXIT_FAILURE);
     }
 
     if (execute_buffer(buf) == -1) {
-        log_line("ifch: execute_buffer was passed invalid commands: '%s'", buf);
+        log_line("%s: (%s) execute_buffer was passed invalid commands: '%s'",
+                 client_config.interface, __func__, buf);
+        inform_execute(0);
         exit(EXIT_FAILURE);
-    }
+    } else
+        inform_execute(1);
 }
 
 void do_ifch_work(void)
diff --git a/ndhc/ndhc.c b/ndhc/ndhc.c
index f9b569a..3522281 100644
--- a/ndhc/ndhc.c
+++ b/ndhc/ndhc.c
@@ -71,6 +71,8 @@
 #include "ifchd.h"
 
 struct client_state_t cs = {
+    .ifchWorking = 0,
+    .ifDeconfig = 0,
     .init = 1,
     .epollFd = -1,
     .signalFd = -1,
@@ -213,9 +215,29 @@ static int get_clientid_mac_string(char *str, size_t slen)
     return 1;
 }
 
+static void handle_ifch_message(void)
+{
+    char c;
+    int r = safe_read(pToNdhcR, &c, sizeof c);
+    if (r == 0) {
+        // Remote end hung up.
+        exit(EXIT_SUCCESS);
+    } else if (r < 0) {
+        if (errno == EAGAIN || errno == EWOULDBLOCK)
+            return;
+        log_line("%s: (%s) error reading from ifch -> ndhc pipe: %s",
+                 client_config.interface, __func__, strerror(errno));
+        exit(EXIT_FAILURE);
+    }
+
+    if (c == '+')
+        cs.ifchWorking = 0;
+}
+
+#define NDHC_NUM_EP_FDS 4
 static void do_ndhc_work(void)
 {
-    struct epoll_event events[3];
+    struct epoll_event events[NDHC_NUM_EP_FDS];
     long long nowts;
     int timeout;
 
@@ -229,12 +251,13 @@ static void do_ndhc_work(void)
     setup_signals_ndhc();
 
     epoll_add(cs.epollFd, cs.nlFd);
+    epoll_add(cs.epollFd, pToNdhcR);
     set_listen_raw(&cs);
     nowts = curms();
     goto jumpstart;
 
     for (;;) {
-        int r = epoll_wait(cs.epollFd, events, 3, timeout);
+        int r = epoll_wait(cs.epollFd, events, NDHC_NUM_EP_FDS, timeout);
         if (r == -1) {
             if (errno == EINTR)
                 continue;
@@ -251,6 +274,8 @@ static void do_ndhc_work(void)
                 handle_arp_response(&cs);
             else if (fd == cs.nlFd)
                 handle_nl_message(&cs);
+            else if (fd == pToNdhcR)
+                handle_ifch_message();
             else
                 suicide("epoll_wait: unknown fd");
         }
@@ -336,7 +361,7 @@ static void ndhc_main(void) {
     drop_root(ndhc_uid, ndhc_gid);
 
     if (cs.ifsPrevState != IFS_UP)
-        ifchange_deconfig();
+        ifchange_deconfig(&cs);
 
     do_ndhc_work();
 }
diff --git a/ndhc/ndhc.h b/ndhc/ndhc.h
index 584d062..f34a461 100644
--- a/ndhc/ndhc.h
+++ b/ndhc/ndhc.h
@@ -38,6 +38,8 @@ struct client_state_t {
     int dhcpState;
     int arpPrevState;
     int ifsPrevState;
+    int ifchWorking; // ifch is performing interface changes.
+    int ifDeconfig; // Set if the interface has already been deconfigured.
     int listenMode;
     int epollFd, signalFd, listenFd, arpFd, nlFd;
     int nlPortId;
diff --git a/ndhc/netlink.c b/ndhc/netlink.c
index 4001de3..d13c258 100644
--- a/ndhc/netlink.c
+++ b/ndhc/netlink.c
@@ -89,6 +89,8 @@ static void nl_process_msgs(const struct nlmsghdr *nlh, void *data)
                 get_if_index_and_mac(nlh, ifm);
             if (ifm->ifi_index != client_config.ifindex)
                 break;
+            if (cs->ifchWorking)
+                break;
             // IFF_UP corresponds to ifconfig down or ifconfig up.
             if (ifm->ifi_flags & IFF_UP) {
                 // IFF_RUNNING is the hardware carrier.
@@ -111,6 +113,8 @@ static void nl_process_msgs(const struct nlmsghdr *nlh, void *data)
         case RTM_DELLINK:
             if (ifm->ifi_index != client_config.ifindex)
                 break;
+            if (cs->ifchWorking)
+                break;
             if (cs->ifsPrevState != IFS_REMOVED) {
                 cs->ifsPrevState = IFS_REMOVED;
                 log_line("Interface removed.  Exiting.");
diff --git a/ndhc/state.c b/ndhc/state.c
index a361b73..71408b4 100644
--- a/ndhc/state.c
+++ b/ndhc/state.c
@@ -88,7 +88,7 @@ static int delay_timeout(size_t numpackets)
 
 static void reinit_shared_deconfig(struct client_state_t *cs)
 {
-    ifchange_deconfig();
+    ifchange_deconfig(cs);
     arp_close_fd(cs);
     cs->clientAddr = 0;
     num_dhcp_requests = 0;