Merge pull request #12429 from ssahani/link-local-fallback

networkd: Option to use LinkLocalAddressing only when DHCP fails

13 files changed, 167 insertions, 64 deletions

diff --git a/man/systemd.network.xml b/man/systemd.network.xml
index 604eea4c18..b86bcf03ef 100644
--- a/man/systemd.network.xml
+++ b/man/systemd.network.xml
@@ -326,9 +326,16 @@
           <term><varname>LinkLocalAddressing=</varname></term>
           <listitem>
             <para>Enables link-local address autoconfiguration. Accepts <literal>yes</literal>,
-            <literal>no</literal>, <literal>ipv4</literal>, or <literal>ipv6</literal>. If
-            <varname>Bridge=</varname> is set, defaults to <literal>no</literal>, and if not,
-            defaults to <literal>ipv6</literal>.</para>
+            <literal>no</literal>, <literal>ipv4</literal>, <literal>ipv6</literal>,
+            <literal>fallback</literal>, or <literal>ipv4-fallback</literal>. If
+            <literal>fallback</literal> or <literal>ipv4-fallback</literal> is specified, then an IPv4
+            link-local address is configured only when DHCPv4 fails. If <literal>fallback</literal>,
+            an IPv6 link-local address is always configured, and if <literal>ipv4-fallback</literal>,
+            the address is not configured. Note that, the fallback mechanism works only when DHCPv4
+            client is enabled, that is, it requires <literal>DHCP=yes</literal> or
+            <literal>DHCP=ipv4</literal>. If <varname>Bridge=</varname> is set, defaults to
+            <literal>no</literal>, and if not, defaults to <literal>ipv6</literal>.
+            </para>
           </listitem>
         </varlistentry>
         <varlistentry>
diff --git a/src/libsystemd-network/sd-dhcp-client.c b/src/libsystemd-network/sd-dhcp-client.c
index 97e1dd3702..f10ae3ed3b 100644
--- a/src/libsystemd-network/sd-dhcp-client.c
+++ b/src/libsystemd-network/sd-dhcp-client.c
@@ -32,6 +32,8 @@
 #define MAX_CLIENT_ID_LEN (sizeof(uint32_t) + MAX_DUID_LEN)  /* Arbitrary limit */
 #define MAX_MAC_ADDR_LEN CONST_MAX(INFINIBAND_ALEN, ETH_ALEN)
 
+#define MAX_CLIENT_ATTEMPT 64
+
 #define RESTART_AFTER_NAK_MIN_USEC (1 * USEC_PER_SEC)
 #define RESTART_AFTER_NAK_MAX_USEC (30 * USEC_PER_MINUTE)
 
@@ -1050,8 +1052,10 @@ static int client_timeout_resend(
         case DHCP_STATE_REQUESTING:
         case DHCP_STATE_BOUND:
 
-                if (client->attempt < 64)
+                if (client->attempt < MAX_CLIENT_ATTEMPT)
                         client->attempt *= 2;
+                else
+                        goto error;
 
                 next_timeout = time_now + (client->attempt - 1) * USEC_PER_SEC;
 
@@ -1079,7 +1083,7 @@ static int client_timeout_resend(
                         client->state = DHCP_STATE_SELECTING;
                         client->attempt = 1;
                 } else {
-                        if (client->attempt >= 64)
+                        if (client->attempt >= MAX_CLIENT_ATTEMPT)
                                 goto error;
                 }
 
@@ -1087,7 +1091,7 @@ static int client_timeout_resend(
 
         case DHCP_STATE_SELECTING:
                 r = client_send_discover(client);
-                if (r < 0 && client->attempt >= 64)
+                if (r < 0 && client->attempt >= MAX_CLIENT_ATTEMPT)
                         goto error;
 
                 break;
@@ -1097,7 +1101,7 @@ static int client_timeout_resend(
         case DHCP_STATE_RENEWING:
         case DHCP_STATE_REBINDING:
                 r = client_send_request(client);
-                if (r < 0 && client->attempt >= 64)
+                if (r < 0 && client->attempt >= MAX_CLIENT_ATTEMPT)
                          goto error;
 
                 if (client->state == DHCP_STATE_INIT_REBOOT)
diff --git a/src/network/networkd-dhcp4.c b/src/network/networkd-dhcp4.c
index 301d9c67b9..c630359027 100644
--- a/src/network/networkd-dhcp4.c
+++ b/src/network/networkd-dhcp4.c
@@ -511,6 +511,7 @@ static int dhcp_lease_acquired(sd_dhcp_client *client, Link *link) {
 
         return 0;
 }
+
 static void dhcp4_handler(sd_dhcp_client *client, int event, void *userdata) {
         Link *link = userdata;
         int r = 0;
@@ -523,9 +524,24 @@ static void dhcp4_handler(sd_dhcp_client *client, int event, void *userdata) {
                 return;
 
         switch (event) {
-                case SD_DHCP_CLIENT_EVENT_EXPIRED:
                 case SD_DHCP_CLIENT_EVENT_STOP:
+
+                        if (link_ipv4ll_fallback_enabled(link)) {
+                                assert(link->ipv4ll);
+
+                                log_link_debug(link, "DHCP client is stopped. Acquiring IPv4 link-local address");
+
+                                r = sd_ipv4ll_start(link->ipv4ll);
+                                if (r < 0) {
+                                        log_link_warning(link, "Could not acquire IPv4 link-local address: %m");
+                                        return;
+                                }
+                        }
+
+                        _fallthrough_;
+                case SD_DHCP_CLIENT_EVENT_EXPIRED:
                 case SD_DHCP_CLIENT_EVENT_IP_CHANGE:
+
                         if (link->network->dhcp_critical) {
                                 log_link_error(link, "DHCPv4 connection considered system critical, ignoring request to reconfigure it.");
                                 return;
diff --git a/src/network/networkd-ipv4ll.c b/src/network/networkd-ipv4ll.c
index 829dc48a0a..fb4bf266a6 100644
--- a/src/network/networkd-ipv4ll.c
+++ b/src/network/networkd-ipv4ll.c
@@ -197,7 +197,7 @@ int ipv4ll_configure(Link *link) {
 
         assert(link);
         assert(link->network);
-        assert(link->network->link_local & ADDRESS_FAMILY_IPV4);
+        assert(link->network->link_local & (ADDRESS_FAMILY_IPV4 | ADDRESS_FAMILY_FALLBACK_IPV4));
 
         if (!link->ipv4ll) {
                 r = sd_ipv4ll_new(&link->ipv4ll);
diff --git a/src/network/networkd-link.c b/src/network/networkd-link.c
index c56b4dfceb..532f2d7f96 100644
--- a/src/network/networkd-link.c
+++ b/src/network/networkd-link.c
@@ -110,7 +110,7 @@ static bool link_dhcp4_server_enabled(Link *link) {
         return link->network->dhcp_server;
 }
 
-static bool link_ipv4ll_enabled(Link *link) {
+bool link_ipv4ll_enabled(Link *link) {
         assert(link);
 
         if (link->flags & IFF_LOOPBACK)
@@ -128,6 +128,24 @@ static bool link_ipv4ll_enabled(Link *link) {
         return link->network->link_local & ADDRESS_FAMILY_IPV4;
 }
 
+bool link_ipv4ll_fallback_enabled(Link *link) {
+        assert(link);
+
+        if (link->flags & IFF_LOOPBACK)
+                return false;
+
+        if (!link->network)
+                return false;
+
+        if (STRPTR_IN_SET(link->kind, "vrf", "wireguard"))
+                return false;
+
+        if (link->network->bond)
+                return false;
+
+        return link->network->link_local & ADDRESS_FAMILY_FALLBACK_IPV4;
+}
+
 static bool link_ipv6ll_enabled(Link *link) {
         assert(link);
 
@@ -994,21 +1012,18 @@ void link_check_ready(Link *link) {
         if (!link->routing_policy_rules_configured)
                 return;
 
-        if (link_ipv4ll_enabled(link))
-                if (!link->ipv4ll_address ||
-                    !link->ipv4ll_route)
-                        return;
+        if (link_ipv4ll_enabled(link) && !(link->ipv4ll_address && link->ipv4ll_route))
+                return;
 
         if (link_ipv6ll_enabled(link) &&
             in_addr_is_null(AF_INET6, (const union in_addr_union*) &link->ipv6ll_address))
                 return;
 
-        if ((link_dhcp4_enabled(link) && !link_dhcp6_enabled(link) &&
-             !link->dhcp4_configured) ||
-            (link_dhcp6_enabled(link) && !link_dhcp4_enabled(link) &&
-             !link->dhcp6_configured) ||
-            (link_dhcp4_enabled(link) && link_dhcp6_enabled(link) &&
-             !link->dhcp4_configured && !link->dhcp6_configured))
+        if ((link_dhcp4_enabled(link) || link_dhcp6_enabled(link)) &&
+            !(link->dhcp4_configured || link->dhcp6_configured) &&
+            !(link_ipv4ll_fallback_enabled(link) && link->ipv4ll_address && link->ipv4ll_route))
+                /* When DHCP is enabled, at least one protocol must provide an address, or
+                 * an IPv4ll fallback address must be configured. */
                 return;
 
         if (link_ipv6_accept_ra_enabled(link) && !link->ndisc_configured)
@@ -3114,7 +3129,7 @@ static int link_configure(Link *link) {
         if (r < 0)
                 return r;
 
-        if (link_ipv4ll_enabled(link)) {
+        if (link_ipv4ll_enabled(link) || link_ipv4ll_fallback_enabled(link)) {
                 r = ipv4ll_configure(link);
                 if (r < 0)
                         return r;
diff --git a/src/network/networkd-link.h b/src/network/networkd-link.h
index 7d8808e400..b43401afc6 100644
--- a/src/network/networkd-link.h
+++ b/src/network/networkd-link.h
@@ -160,6 +160,9 @@ int link_ipv6ll_gained(Link *link, const struct in6_addr *address);
 int link_set_mtu(Link *link, uint32_t mtu, bool force);
 
 int ipv4ll_configure(Link *link);
+bool link_ipv4ll_enabled(Link *link);
+bool link_ipv4ll_fallback_enabled(Link *link);
+
 int dhcp4_configure(Link *link);
 int dhcp4_set_client_identifier(Link *link);
 int dhcp4_set_promote_secondaries(Link *link);
diff --git a/src/network/networkd-network-gperf.gperf b/src/network/networkd-network-gperf.gperf
index 653da83c9f..8232b069a8 100644
--- a/src/network/networkd-network-gperf.gperf
+++ b/src/network/networkd-network-gperf.gperf
@@ -51,7 +51,7 @@ Network.Tunnel,                         config_parse_stacked_netdev,
 Network.VRF,                            config_parse_ifname,                             0,                             offsetof(Network, vrf_name)
 Network.DHCP,                           config_parse_dhcp,                               0,                             offsetof(Network, dhcp)
 Network.DHCPServer,                     config_parse_bool,                               0,                             offsetof(Network, dhcp_server)
-Network.LinkLocalAddressing,            config_parse_address_family_boolean,             0,                             offsetof(Network, link_local)
+Network.LinkLocalAddressing,            config_parse_link_local_address_family_boolean,  0,                             offsetof(Network, link_local)
 Network.IPv4LLRoute,                    config_parse_bool,                               0,                             offsetof(Network, ipv4ll_route)
 Network.IPv6Token,                      config_parse_ipv6token,                          0,                             offsetof(Network, ipv6_token)
 Network.LLDP,                           config_parse_lldp_mode,                          0,                             offsetof(Network, lldp_mode)
diff --git a/src/network/networkd-network.c b/src/network/networkd-network.c
index 1828d1126c..a85d5ede28 100644
--- a/src/network/networkd-network.c
+++ b/src/network/networkd-network.c
@@ -236,6 +236,13 @@ int network_verify(Network *network) {
         if (network->link_local < 0)
                 network->link_local = network->bridge ? ADDRESS_FAMILY_NO : ADDRESS_FAMILY_IPV6;
 
+        if (FLAGS_SET(network->link_local, ADDRESS_FAMILY_FALLBACK_IPV4) &&
+            !FLAGS_SET(network->dhcp, ADDRESS_FAMILY_IPV4)) {
+                log_warning("%s: fallback assignment of IPv4 link local address is enabled but DHCPv4 is disabled. "
+                            "Disabling the fallback assignment.", network->filename);
+                SET_FLAG(network->link_local, ADDRESS_FAMILY_FALLBACK_IPV4, false);
+        }
+
         if (network->ipv6_accept_ra < 0 && network->bridge)
                 network->ipv6_accept_ra = false;
 
@@ -818,6 +825,7 @@ int config_parse_ipv4ll(
                 void *userdata) {
 
         AddressFamilyBoolean *link_local = data;
+        int r;
 
         assert(filename);
         assert(lvalue);
@@ -828,7 +836,20 @@ int config_parse_ipv4ll(
          * config_parse_address_family_boolean(), except that it
          * applies only to IPv4 */
 
-        SET_FLAG(*link_local, ADDRESS_FAMILY_IPV4, parse_boolean(rvalue));
+        r = parse_boolean(rvalue);
+        if (r < 0) {
+                log_syntax(unit, LOG_ERR, filename, line, r,
+                           "Failed to parse %s=%s, ignoring assignment. "
+                           "Note that the setting %s= is deprecated, please use LinkLocalAddressing= instead.",
+                           lvalue, rvalue, lvalue);
+                return 0;
+        }
+
+        SET_FLAG(*link_local, ADDRESS_FAMILY_IPV4, r);
+
+        log_syntax(unit, LOG_WARNING, filename, line, 0,
+                   "%s=%s is deprecated, please use LinkLocalAddressing=%s instead.",
+                   lvalue, rvalue, address_family_boolean_to_string(*link_local));
 
         return 0;
 }
diff --git a/src/network/networkd-util.c b/src/network/networkd-util.c
index a088d25981..d01de53f7b 100644
--- a/src/network/networkd-util.c
+++ b/src/network/networkd-util.c
@@ -8,38 +8,26 @@
 #include "string-util.h"
 #include "util.h"
 
-const char *address_family_boolean_to_string(AddressFamilyBoolean b) {
-        if (IN_SET(b, ADDRESS_FAMILY_YES, ADDRESS_FAMILY_NO))
-                return yes_no(b == ADDRESS_FAMILY_YES);
-
-        if (b == ADDRESS_FAMILY_IPV4)
-                return "ipv4";
-        if (b == ADDRESS_FAMILY_IPV6)
-                return "ipv6";
-
-        return NULL;
-}
-
-AddressFamilyBoolean address_family_boolean_from_string(const char *s) {
-        int r;
-
-        /* Make this a true superset of a boolean */
-
-        r = parse_boolean(s);
-        if (r > 0)
-                return ADDRESS_FAMILY_YES;
-        if (r == 0)
-                return ADDRESS_FAMILY_NO;
-
-        if (streq(s, "ipv4"))
-                return ADDRESS_FAMILY_IPV4;
-        if (streq(s, "ipv6"))
-                return ADDRESS_FAMILY_IPV6;
-
-        return _ADDRESS_FAMILY_BOOLEAN_INVALID;
-}
-
-DEFINE_CONFIG_PARSE_ENUM(config_parse_address_family_boolean, address_family_boolean, AddressFamilyBoolean, "Failed to parse option");
+static const char * const address_family_boolean_table[_ADDRESS_FAMILY_BOOLEAN_MAX] = {
+        [ADDRESS_FAMILY_NO]            = "no",
+        [ADDRESS_FAMILY_YES]           = "yes",
+        [ADDRESS_FAMILY_IPV4]          = "ipv4",
+        [ADDRESS_FAMILY_IPV6]          = "ipv6",
+};
+
+static const char * const link_local_address_family_boolean_table[_ADDRESS_FAMILY_BOOLEAN_MAX] = {
+        [ADDRESS_FAMILY_NO]            = "no",
+        [ADDRESS_FAMILY_YES]           = "yes",
+        [ADDRESS_FAMILY_IPV4]          = "ipv4",
+        [ADDRESS_FAMILY_IPV6]          = "ipv6",
+        [ADDRESS_FAMILY_FALLBACK]      = "fallback",
+        [ADDRESS_FAMILY_FALLBACK_IPV4] = "ipv4-fallback",
+};
+
+DEFINE_STRING_TABLE_LOOKUP_WITH_BOOLEAN(address_family_boolean, AddressFamilyBoolean, ADDRESS_FAMILY_YES);
+DEFINE_STRING_TABLE_LOOKUP_WITH_BOOLEAN(link_local_address_family_boolean, AddressFamilyBoolean, ADDRESS_FAMILY_YES);
+DEFINE_CONFIG_PARSE_ENUM(config_parse_link_local_address_family_boolean, link_local_address_family_boolean,
+                         AddressFamilyBoolean, "Failed to parse option");
 
 int config_parse_address_family_boolean_with_kernel(
                 const char* unit,
diff --git a/src/network/networkd-util.h b/src/network/networkd-util.h
index 9c472cfd50..aafbac7df6 100644
--- a/src/network/networkd-util.h
+++ b/src/network/networkd-util.h
@@ -7,10 +7,12 @@
 
 typedef enum AddressFamilyBoolean {
         /* This is a bitmask, though it usually doesn't feel that way! */
-        ADDRESS_FAMILY_NO   = 0,
-        ADDRESS_FAMILY_IPV4 = 1 << 0,
-        ADDRESS_FAMILY_IPV6 = 1 << 1,
-        ADDRESS_FAMILY_YES  = ADDRESS_FAMILY_IPV4 | ADDRESS_FAMILY_IPV6,
+        ADDRESS_FAMILY_NO             = 0,
+        ADDRESS_FAMILY_IPV4           = 1 << 0,
+        ADDRESS_FAMILY_IPV6           = 1 << 1,
+        ADDRESS_FAMILY_YES            = ADDRESS_FAMILY_IPV4 | ADDRESS_FAMILY_IPV6,
+        ADDRESS_FAMILY_FALLBACK_IPV4  = 1 << 2,
+        ADDRESS_FAMILY_FALLBACK       = ADDRESS_FAMILY_FALLBACK_IPV4 | ADDRESS_FAMILY_IPV6,
         _ADDRESS_FAMILY_BOOLEAN_MAX,
         _ADDRESS_FAMILY_BOOLEAN_INVALID = -1,
 } AddressFamilyBoolean;
@@ -21,11 +23,14 @@ typedef struct NetworkConfigSection {
         char filename[];
 } NetworkConfigSection;
 
-CONFIG_PARSER_PROTOTYPE(config_parse_address_family_boolean);
+CONFIG_PARSER_PROTOTYPE(config_parse_link_local_address_family_boolean);
 CONFIG_PARSER_PROTOTYPE(config_parse_address_family_boolean_with_kernel);
 
 const char *address_family_boolean_to_string(AddressFamilyBoolean b) _const_;
-AddressFamilyBoolean address_family_boolean_from_string(const char *s) _const_;
+AddressFamilyBoolean address_family_boolean_from_string(const char *s) _pure_;
+
+const char *link_local_address_family_boolean_to_string(AddressFamilyBoolean b) _const_;
+AddressFamilyBoolean link_local_address_family_boolean_from_string(const char *s) _pure_;
 
 int kernel_route_expiration_supported(void);
 
diff --git a/src/network/test-network-tables.c b/src/network/test-network-tables.c
index 6b110b7110..711954e4a2 100644
--- a/src/network/test-network-tables.c
+++ b/src/network/test-network-tables.c
@@ -14,7 +14,6 @@
 #include "test-tables.h"
 
 int main(int argc, char **argv) {
-        test_table(address_family_boolean, ADDRESS_FAMILY_BOOLEAN);
         test_table(bond_ad_select, NETDEV_BOND_AD_SELECT);
         test_table(bond_arp_all_targets, NETDEV_BOND_ARP_ALL_TARGETS);
         test_table(bond_arp_validate, NETDEV_BOND_ARP_VALIDATE);
@@ -42,6 +41,7 @@ int main(int argc, char **argv) {
 
         test_table_sparse(ipvlan_mode, NETDEV_IPVLAN_MODE);
         test_table_sparse(macvlan_mode, NETDEV_MACVLAN_MODE);
+        test_table_sparse(address_family_boolean, ADDRESS_FAMILY_BOOLEAN);
 
         return EXIT_SUCCESS;
 }
diff --git a/test/test-network/conf/dhcp-client-with-ipv4ll-fallback.network b/test/test-network/conf/dhcp-client-with-ipv4ll-fallback.network
new file mode 100644
index 0000000000..9ebdbb4f8d
--- /dev/null
+++ b/test/test-network/conf/dhcp-client-with-ipv4ll-fallback.network
@@ -0,0 +1,7 @@
+[Match]
+Name=veth99
+
+[Network]
+DHCP=ipv4
+LinkLocalAddressing=fallback
+IPv6AcceptRA=no
diff --git a/test/test-network/systemd-networkd-tests.py b/test/test-network/systemd-networkd-tests.py
index 73c0edb38e..184ab2d03a 100755
--- a/test/test-network/systemd-networkd-tests.py
+++ b/test/test-network/systemd-networkd-tests.py
@@ -139,8 +139,8 @@ class Utilities():
                 if (os.path.exists(os.path.join(network_unit_file_path, unit + '.d'))):
                     shutil.rmtree(os.path.join(network_unit_file_path, unit + '.d'))
 
-    def start_dnsmasq(self, additional_options=''):
-        dnsmasq_command = 'dnsmasq -8 /var/run/networkd-ci/test-dnsmasq-log-file --log-queries=extra --log-dhcp --pid-file=/var/run/networkd-ci/test-test-dnsmasq.pid --conf-file=/dev/null --interface=veth-peer --enable-ra --dhcp-range=2600::10,2600::20 --dhcp-range=192.168.5.10,192.168.5.200 -R --dhcp-leasefile=/var/run/networkd-ci/lease --dhcp-option=26,1492 --dhcp-option=option:router,192.168.5.1 --dhcp-option=33,192.168.5.4,192.168.5.5 --port=0 ' + additional_options
+    def start_dnsmasq(self, additional_options='', lease_time='1h'):
+        dnsmasq_command = f'dnsmasq -8 /var/run/networkd-ci/test-dnsmasq-log-file --log-queries=extra --log-dhcp --pid-file=/var/run/networkd-ci/test-test-dnsmasq.pid --conf-file=/dev/null --interface=veth-peer --enable-ra --dhcp-range=2600::10,2600::20,{lease_time} --dhcp-range=192.168.5.10,192.168.5.200,{lease_time} -R --dhcp-leasefile=/var/run/networkd-ci/lease --dhcp-option=26,1492 --dhcp-option=option:router,192.168.5.1 --dhcp-option=33,192.168.5.4,192.168.5.5 --port=0 ' + additional_options
         subprocess.check_call(dnsmasq_command, shell=True)
 
         time.sleep(10)
@@ -1880,6 +1880,7 @@ class NetworkdNetworkDHCPClientTests(unittest.TestCase, Utilities):
         'dhcp-client-route-metric.network',
         'dhcp-client-route-table.network',
         'dhcp-client-vrf.network',
+        'dhcp-client-with-ipv4ll-fallback.network',
         'dhcp-client.network',
         'dhcp-server-veth-peer.network',
         'dhcp-v4-server-veth-peer.network',
@@ -2176,6 +2177,42 @@ class NetworkdNetworkDHCPClientTests(unittest.TestCase, Utilities):
         print(output)
         self.assertRegex(output, 'onlink')
 
+    def test_dhcp_client_with_ipv4ll_fallback(self):
+        self.copy_unit_to_networkd_unit_path('25-veth.netdev', 'dhcp-server-veth-peer.network',
+                                             'dhcp-client-with-ipv4ll-fallback.network')
+        self.start_networkd(0)
+        self.start_dnsmasq(lease_time='2m')
+        self.wait_online(['veth99:routable', 'veth-peer:routable'])
+
+        output = subprocess.check_output(['ip', 'address', 'show', 'dev', 'veth99']).rstrip().decode('utf-8')
+        print(output)
+
+        output = subprocess.check_output(['ip', '-6', 'address', 'show', 'dev', 'veth99', 'scope', 'global', 'dynamic']).rstrip().decode('utf-8')
+        self.assertNotRegex(output, 'inet6 2600::[0-9a-f]*/128 scope global dynamic')
+        output = subprocess.check_output(['ip', '-6', 'address', 'show', 'dev', 'veth99', 'scope', 'link']).rstrip().decode('utf-8')
+        self.assertRegex(output, 'inet6 .* scope link')
+        output = subprocess.check_output(['ip', '-4', 'address', 'show', 'dev', 'veth99', 'scope', 'global', 'dynamic']).rstrip().decode('utf-8')
+        self.assertRegex(output, 'inet 192.168.5.[0-9]*/24 brd 192.168.5.255 scope global dynamic veth99')
+        output = subprocess.check_output(['ip', '-4', 'address', 'show', 'dev', 'veth99', 'scope', 'link']).rstrip().decode('utf-8')
+        self.assertNotRegex(output, 'inet .* scope link')
+
+        print('Wait for the dynamic address to be expired')
+        time.sleep(130)
+
+        output = subprocess.check_output(['ip', 'address', 'show', 'dev', 'veth99']).rstrip().decode('utf-8')
+        print(output)
+
+        output = subprocess.check_output(['ip', '-6', 'address', 'show', 'dev', 'veth99', 'scope', 'global', 'dynamic']).rstrip().decode('utf-8')
+        self.assertNotRegex(output, 'inet6 2600::[0-9a-f]*/128 scope global dynamic')
+        output = subprocess.check_output(['ip', '-6', 'address', 'show', 'dev', 'veth99', 'scope', 'link']).rstrip().decode('utf-8')
+        self.assertRegex(output, 'inet6 .* scope link')
+        output = subprocess.check_output(['ip', '-4', 'address', 'show', 'dev', 'veth99', 'scope', 'global', 'dynamic']).rstrip().decode('utf-8')
+        self.assertRegex(output, 'inet 192.168.5.[0-9]*/24 brd 192.168.5.255 scope global dynamic veth99')
+        output = subprocess.check_output(['ip', '-4', 'address', 'show', 'dev', 'veth99', 'scope', 'link']).rstrip().decode('utf-8')
+        self.assertNotRegex(output, 'inet .* scope link')
+
+        self.search_words_in_dnsmasq_log('DHCPOFFER', show_all=True)
+
 if __name__ == '__main__':
     unittest.main(testRunner=unittest.TextTestRunner(stream=sys.stdout,
                                                      verbosity=3))