diff --git a/repos/os/src/server/nic_router/dhcp_server.cc b/repos/os/src/server/nic_router/dhcp_server.cc
index 65cf000c5b..9344f091a0 100644
--- a/repos/os/src/server/nic_router/dhcp_server.cc
+++ b/repos/os/src/server/nic_router/dhcp_server.cc
@@ -150,9 +150,27 @@ void Dhcp_server::alloc_ip(Ipv4_address const &ip)
 }
 
 
-void Dhcp_server::free_ip(Ipv4_address const &ip)
+void Dhcp_server::free_ip(Domain       const &domain,
+                          Ipv4_address const &ip)
 {
-	_ip_alloc.free(ip.to_uint32_little_endian() - _ip_first_raw);
+	try {
+		_ip_alloc.free(ip.to_uint32_little_endian() - _ip_first_raw);
+	}
+	catch (Bit_allocator_dynamic::Out_of_indices) {
+
+		/*
+		 * This message is printed independent from the routers
+		 * verbosity configuration in order to track down an exception
+		 * of type Bit_allocator_dynamic::Out_of_indices that was
+		 * previously not caught. We have observed this exception once,
+		 * but without a specific use pattern that would
+		 * enable for a systematic reproduction of the issue.
+		 * The uncaught exception was observed in a 21.03 Sculpt OS
+		 * with a manually configured router, re-configuration involved.
+		 */
+		log("[", domain, "] DHCP server: failed to free IP ",
+		    ip, " (IP range: first ", _ip_first, " last ", _ip_last, ")");
+	}
 }
 
 
diff --git a/repos/os/src/server/nic_router/dhcp_server.h b/repos/os/src/server/nic_router/dhcp_server.h
index 6f9888d068..c31f286178 100644
--- a/repos/os/src/server/nic_router/dhcp_server.h
+++ b/repos/os/src/server/nic_router/dhcp_server.h
@@ -100,7 +100,8 @@ class Net::Dhcp_server : private Genode::Noncopyable,
 
 		void alloc_ip(Ipv4_address const &ip);
 
-		void free_ip(Ipv4_address const &ip);
+		void free_ip(Domain       const &domain,
+		             Ipv4_address const &ip);
 
 		bool ready() const;
 
diff --git a/repos/os/src/server/nic_router/domain.cc b/repos/os/src/server/nic_router/domain.cc
index 7b26e9379f..25e0380a2f 100644
--- a/repos/os/src/server/nic_router/domain.cc
+++ b/repos/os/src/server/nic_router/domain.cc
@@ -258,16 +258,42 @@ void Domain::init(Domain_tree &domains)
 		if (_ip_config_dynamic) {
 			_invalid("DHCP server and client at once"); }
 
-		Dhcp_server &dhcp_server = *new (_alloc)
-			Dhcp_server(dhcp_server_node, *this, _alloc,
-			            ip_config().interface, domains);
+		try {
+			Dhcp_server &dhcp_server = *new (_alloc)
+				Dhcp_server(dhcp_server_node, *this, _alloc,
+				            ip_config().interface, domains);
 
-		try { dhcp_server.dns_server_from().ip_config_dependents().insert(this); }
-		catch (Pointer<Domain>::Invalid) { }
+			try {
+				dhcp_server.
+					dns_server_from().ip_config_dependents().insert(this);
+			}
+			catch (Pointer<Domain>::Invalid) { }
 
-		_dhcp_server = dhcp_server;
-		if (_config.verbose()) {
-			log("[", *this, "] DHCP server: ", _dhcp_server()); }
+			_dhcp_server = dhcp_server;
+			if (_config.verbose()) {
+				log("[", *this, "] DHCP server: ", _dhcp_server()); }
+		}
+		catch (Bit_allocator_dynamic::Out_of_indices) {
+
+			/*
+			 * This message is printed independent from the routers
+			 * verbosity configuration in order to track down an exception
+			 * of type Bit_allocator_dynamic::Out_of_indices that was
+			 * previously not caught. We have observed this exception once,
+			 * but without a specific use pattern that would
+			 * enable for a systematic reproduction of the issue.
+			 * The uncaught exception was observed in a 21.03 Sculpt OS
+			 * with a manually configured router, re-configuration involved.
+			 */
+			log("[", *this, "] DHCP server: failed to initialize ",
+			    "(IP range: first ",
+			    dhcp_server_node.attribute_value("ip_first", Ipv4_address()),
+			    " last ",
+			    dhcp_server_node.attribute_value("ip_last", Ipv4_address()),
+			    ")");
+
+			throw Dhcp_server::Invalid { };
+		}
 	}
 	catch (Xml_node::Nonexistent_sub_node) { }
 	catch (Dhcp_server::Invalid) { _invalid("invalid DHCP server"); }
diff --git a/repos/os/src/server/nic_router/interface.cc b/repos/os/src/server/nic_router/interface.cc
index b5969e1cc5..6e9d3c9910 100644
--- a/repos/os/src/server/nic_router/interface.cc
+++ b/repos/os/src/server/nic_router/interface.cc
@@ -1488,7 +1488,7 @@ void Interface::_ready_to_ack()
 void Interface::_destroy_dhcp_allocation(Dhcp_allocation &allocation,
                                          Domain          &local_domain)
 {
-	try { local_domain.dhcp_server().free_ip(allocation.ip()); }
+	try { local_domain.dhcp_server().free_ip(local_domain, allocation.ip()); }
 	catch (Pointer<Dhcp_server>::Invalid) { }
 	destroy(_alloc, &allocation);
 }