adamgeorge309 · Oct 15, 2026
diff --git a/WHATSNEW b/WHATSNEW
@@ -471,6 +471,10 @@ Notable bug fixes are the following:
 
    The HT mode factory now includes band and preamble format in its cache key. A 5 GHz request after an equivalent 2.4 GHz request therefore receives the requested band and timing. Previously, that request could receive the earlier mode. Identical complete requests still reuse one object.
 
+2. A router sends no Router Advertisement while its link-local address is tentative
+
+   A router sent Router Advertisements from its link-local address while Duplicate Address Detection for that address was running, and before it started, although RFC 4861 Section 4.2 requires the source to be the assigned link-local address, Section 6.2.2 allows them only on an interface with an assigned unicast address, and RFC 4862 does not count a tentative address as assigned. Periodic, solicited and Proxy Mobile IPv6 advertisements are now not sent while the link-local address is tentative; a solicited advertisement that is due after the address is verified is sent as before. Simulations with short advertisement intervals, or with advertisements solicited or sent by Proxy Mobile IPv6 while a router is still verifying its address, produce different results, for example in examples/manetrouting/dymo, examples/ipv6/pmipv6 and examples/inet/hierarchical99.
+
 
 INET-4.7 (July 2026) — feature release
 --------------------------------------

diff --git a/src/inet/networklayer/icmpv6/Ipv6NeighbourDiscovery.cc b/src/inet/networklayer/icmpv6/Ipv6NeighbourDiscovery.cc
@@ -1258,9 +1258,15 @@ bool Ipv6NeighbourDiscovery::validateRsPacket(Packet *packet, const Ipv6RouterSo
 
 void Ipv6NeighbourDiscovery::createAndSendRaPacket(const Ipv6Address& destAddr, NetworkInterface *ie)
 {
-    EV_INFO << "Create and send RA invoked!\n";
     // Must use link-local addr. See: RFC2461 Section 6.1.2
     Ipv6Address sourceAddr = ie->getProtocolData<Ipv6InterfaceData>()->getLinkLocalAddress();
+    // RFC 4861 Section 4.2: the source is the link-local address assigned to the interface,
+    // and a tentative address is not assigned (RFC 4862 Section 5.4)
+    if (ie->getProtocolData<Ipv6InterfaceData>()->isTentativeAddress(sourceAddr)) {
+        EV_INFO << "Link-local address " << sourceAddr << " is tentative, RA not sent\n";
+        return;
+    }
+    EV_INFO << "Create and send RA invoked!\n";
 
     // This operation includes all options, regardless whether it is solicited or unsolicited.
     if (ie->getProtocolData<Ipv6InterfaceData>()->getAdvSendAdvertisements()) { // if this is an advertising interface
@@ -1682,8 +1688,14 @@ void Ipv6NeighbourDiscovery::sendPeriodicRa(cMessage *msg)
     NetworkInterface *ie = (NetworkInterface *)msg->getContextPointer();
     AdvIfEntry *advIfEntry = fetchAdvIfEntry(ie);
     Ipv6Address destAddr = Ipv6Address("FF02::1");
-    createAndSendRaPacket(destAddr, ie);
-    advIfEntry->numRASent++;
+    // an RA that is not sent while the link-local address is tentative does not count
+    // as one of the initial advertisements
+    if (!ie->getProtocolData<Ipv6InterfaceData>()->isTentativeAddress(ie->getProtocolData<Ipv6InterfaceData>()->getLinkLocalAddress())) {
+        createAndSendRaPacket(destAddr, ie);
+        advIfEntry->numRASent++;
+    }
+    else
+        EV_INFO << "Link-local address is tentative, periodic RA not sent\n";
 
     // RFC 2461, Section 6.2.4
     /*Whenever a multicast advertisement is sent from an interface, the timer is
@@ -1726,6 +1738,12 @@ void Ipv6NeighbourDiscovery::sendSolicitedRa(cMessage *msg)
     NetworkInterface *ie = (NetworkInterface *)msg->getContextPointer();
     Ipv6Address destAddr = Ipv6Address("FF02::1");
     EV_DETAIL << "Testing condition!\n";
+    if (ie->getProtocolData<Ipv6InterfaceData>()->isTentativeAddress(ie->getProtocolData<Ipv6InterfaceData>()->getLinkLocalAddress())) {
+        // createAndSendRaPacket() sends nothing; processRsPacket() took this RA as the next
+        // scheduled one, so point back at the periodic RA, or later RSs would be ignored
+        if (AdvIfEntry *advIfEntry = fetchAdvIfEntry(ie))
+            advIfEntry->nextScheduledRATime = advIfEntry->raTimeoutMsg->getArrivalTime();
+    }
     createAndSendRaPacket(destAddr, ie);
     delete msg;
 }

diff --git a/tests/fingerprint/examples.csv b/tests/fingerprint/examples.csv
@@ -165,7 +165,7 @@
 
 # /examples/inet/hierarchical99/,      -f .qtenv.ini -c General -r 0
 /examples/inet/hierarchical99/,      -f networklayer.ini -c IPv4 -r 0,              10000s,          a94d-edae/tplx;1f32-e325/~tNl;b138-ee8b/~tND;66c9-cd73/tyf, PASS, EthernetMac Ipv4
-/examples/inet/hierarchical99/,      -f networklayer.ini -c IPv6 -r 0,              10000s,          0001-0108/tplx;3960-479e/~tNl;add1-e848/~tND;2c03-abef/tyf, PASS, EthernetMac
+/examples/inet/hierarchical99/,      -f networklayer.ini -c IPv6 -r 0,              10000s,          2066-f2bb/tplx;a251-4e01/~tNl;0502-0a17/~tND;b45b-90f6/tyf, PASS, EthernetMac
 /examples/inet/hierarchical99/,      -f networklayer.ini -c Generic -r 0,           10000s,          6ae4-6e75/tplx;2209-80ac/~tNl;93bf-6657/tyf, PASS, EthernetMac
 /examples/inet/hierarchical99/,      -f networklayer.ini -c Flooding -r 0,          10000s,          7ba7-5b91/tplx;b0f0-411e/~tNl;2b94-8906/tyf, PASS, EthernetMac
 /examples/inet/hierarchical99/,      -f networklayer.ini -c ProbabilisticBroadcast -r 0,              10000s,          5a54-9779/tplx;1165-a70b/~tNl;760b-abfc/tyf, PASS, EthernetMac
@@ -348,16 +348,16 @@
 # /examples/manetrouting/dymo/,        -f omnetpp.ini -c _IPv4 -r 0      # abstract-config
 /examples/manetrouting/dymo/,        -f omnetpp.ini -c IPv4 -r 0,                   10s,             1a85-cb5d/tplx;dfe8-11b9/~tNl;2b10-4dcb/tyf, PASS,  wireless adhoc Ipv4
 # /examples/manetrouting/dymo/,        -f omnetpp.ini -c _IPv6 -r 0      # abstract-config
-/examples/manetrouting/dymo/,        -f omnetpp.ini -c IPv6 -r 0,                   10s,             d3ef-c8cf/tplx;fd53-3e15/~tNl;8301-9264/tyf, PASS,  wireless adhoc
+/examples/manetrouting/dymo/,        -f omnetpp.ini -c IPv6 -r 0,                   10s,             e6da-b593/tplx;145b-4eb1/~tNl;b4b9-189a/tyf, PASS,  wireless adhoc
 # /examples/manetrouting/dymo/,        -f omnetpp.ini -c _Generic -r 0   # abstract-config
 /examples/manetrouting/dymo/,        -f omnetpp.ini -c Generic -r 0,                10s,             5f8a-7174/tplx;9713-e7fe/~tNl;5716-c166/tyf, PASS,  wireless adhoc
 # /examples/manetrouting/dymo/,        -f omnetpp.ini -c _Multi -r 0     # abstract-config
 /examples/manetrouting/dymo/,        -f omnetpp.ini -c MultiIPv4 -r 0,              10s,             b346-3570/tplx;7bce-e34f/~tNl;4782-99e5/tyf, PASS,  wireless adhoc Ipv4
-/examples/manetrouting/dymo/,        -f omnetpp.ini -c MultiIPv6 -r 0,              10s,             d3ef-c8cf/tplx;fd53-3e15/~tNl;3ba7-352e/tyf, PASS,  wireless adhoc
+/examples/manetrouting/dymo/,        -f omnetpp.ini -c MultiIPv6 -r 0,              10s,             e6da-b593/tplx;145b-4eb1/~tNl;0adc-8b6a/tyf, PASS,  wireless adhoc
 /examples/manetrouting/dymo/,        -f omnetpp.ini -c MultiGeneric -r 0,           10s,             0354-6dd4/tplx;735c-957d/~tNl;31f0-2788/tyf, PASS,  wireless adhoc
 # /examples/manetrouting/dymo/,        -f omnetpp.ini -c _Dynamic -r 0   # abstract-config
 /examples/manetrouting/dymo/,        -f omnetpp.ini -c DynamicIPv4 -r 0,            22s,             2f57-3280/tplx;8f96-3d9c/~tNl;c33f-4f8c/tyf, PASS,  wireless adhoc Ipv4
-/examples/manetrouting/dymo/,        -f omnetpp.ini -c DynamicIPv6 -r 0,            22s,             1e32-4f69/tplx;c684-e25f/~tNl;3469-a611/tyf, PASS,  wireless adhoc
+/examples/manetrouting/dymo/,        -f omnetpp.ini -c DynamicIPv6 -r 0,            22s,             cc61-27bb/tplx;c396-a2df/~tNl;749c-1382/tyf, PASS,  wireless adhoc
 /examples/manetrouting/dymo/,        -f omnetpp.ini -c DynamicGeneric -r 0,         22s,             b68e-dfe3/tplx;9c68-c2d4/~tNl;8c4d-6bc7/tyf, PASS,  wireless adhoc
 
 # /examples/manetrouting/gpsr/,        -f omnetpp.ini -c Random -r 0,    # abstract-config
@@ -383,7 +383,7 @@
 /examples/ipv6/mipv6/,               -f omnetpp.ini -c Handover -r 0,                70s,             68ea-9693/tplx;a44c-17bf/~tNl;96ff-ed7c/~tND;44ef-1a45/tyf, PASS, wireless EthernetMac
 /examples/ipv6/mipv6/,               -f omnetpp.ini -c RouteOptimizationTwoCNs -r 0,  60s,             bacf-986a/tplx;e6db-28c0/~tNl;805b-8a25/~tND;ed3e-17fa/tyf, PASS, wireless EthernetMac
 /examples/ipv6/mipv6roaming/,        -f omnetpp.ini -c Roaming -r 0,                 70s,             b275-b584/tplx;28ce-974e/~tNl;dcec-ae59/~tND;afae-2b3c/tyf, PASS, wireless EthernetMac
-/examples/ipv6/pmipv6/,              -f omnetpp.ini -c General -r 0,                 60s,             e801-4d1a/tplx;1064-9bd4/~tNl;bd46-d85c/~tND;0277-d784/tyf, PASS, wireless EthernetMac
+/examples/ipv6/pmipv6/,              -f omnetpp.ini -c General -r 0,                 60s,             1ace-6963/tplx;117c-4089/~tNl;ddb3-870d/~tND;62ee-3f4a/tyf, PASS, wireless EthernetMac
 
 /examples/mobility/,                 -f omnetpp.ini -c AnsimMobility -r 0,          10000s,          72f8-5c0b/tplx;0000-0000/~tNl;0000-0000/~tND;7dd1-18eb/tyf, PASS,
 /examples/mobility,                  -f omnetpp.ini -c AttachedMobility,            10s,             566c-6355/tplx;0000-0000/~tNl;0000-0000/~tND;fa92-f68c/tyf, PASS,

diff --git a/tests/fingerprint/mipv6-refactoring.csv b/tests/fingerprint/mipv6-refactoring.csv
@@ -23,14 +23,14 @@
 /examples/ipv6/nclients/,            -f omnetpp.ini -c PPP_SCTP -r 0,               100s,            3a7c-924c/~tNlb, PASS,
 
 # IPv6 networking examples
-/examples/inet/hierarchical99/,      -f networklayer.ini -c IPv6 -r 0,              10000s,          f206-a0e2/~tNlb, PASS, EthernetMac
+/examples/inet/hierarchical99/,      -f networklayer.ini -c IPv6 -r 0,              10000s,          5836-f09b/~tNlb, PASS, EthernetMac
 /examples/inet/udpclientserver/,     -f omnetpp.ini -c udp_OK_ipv6 -r 0,            10s,             8feb-3936/~tNlb, PASS,
 /examples/inet/udpclientserver/,     -f omnetpp.ini -c udp_Port_Unav_ipv6 -r 0,     10s,             9661-c1f5/~tNlb, PASS,
 /examples/inet/udpclientserver/,     -f omnetpp.ini -c udp_Host_Unav_ipv6 -r 0,     10s,             6360-9ed1/~tNlb, PASS,
 
 # DYMO with IPv6
-/examples/manetrouting/dymo/,        -f omnetpp.ini -c IPv6 -r 0,                   10s,             d23a-ce35/~tNlb, PASS,  wireless adhoc
-/examples/manetrouting/dymo/,        -f omnetpp.ini -c MultiIPv6 -r 0,              10s,             d23a-ce35/~tNlb, PASS,  wireless adhoc
+/examples/manetrouting/dymo/,        -f omnetpp.ini -c IPv6 -r 0,                   10s,             cbc4-92bf/~tNlb, PASS,  wireless adhoc
+/examples/manetrouting/dymo/,        -f omnetpp.ini -c MultiIPv6 -r 0,              10s,             cbc4-92bf/~tNlb, PASS,  wireless adhoc
 
 # EIGRP with IPv6
 /examples/eigrp/testing_scenario6/,    -f omnetpp.ini -c EIGRP-IPv6_exp1_bandwidth-change -r 0,              3min,         c645-565e/~tNlb,  PASS,  eigrp EthernetMac

diff --git a/tests/module/IPv6_ND_no_router_advertisement_from_tentative_address.test b/tests/module/IPv6_ND_no_router_advertisement_from_tentative_address.test
@@ -0,0 +1,63 @@
+%description:
+A router sends no Router Advertisement while its link-local address is tentative: RFC 4861
+Section 6.2.2 forbids Router Advertisements on an interface that is not an advertising
+interface, which needs an assigned unicast address, and RFC 4862 Section 5.4 does not count
+a tentative address as assigned.
+
+Topology: router -- host
+
+The router's Router Advertisement interval is 30-70 ms, shorter than its Duplicate Address
+Detection (DAD) for the link-local address. Only the router's Neighbour Discovery logs, so
+no "Create and send RA invoked!" line may come before its "DAD completed for address fe80"
+line, and at least one must come after it.
+
+%#--------------------------------------------------------------------------------------------------------------
+%file: test.ned
+
+import inet.networklayer.configurator.ipv6.Ipv6FlatNetworkConfigurator;
+import inet.node.ipv6.Router6;
+import inet.node.ipv6.StandardHost6;
+import ned.DatarateChannel;
+
+network TentativeRouterAdvertisementTest
+{
+    types:
+        channel ethline extends DatarateChannel
+        {
+            delay = 0.1us;
+            datarate = 10Mbps;
+        }
+    submodules:
+        configurator: Ipv6FlatNetworkConfigurator;
+        router: Router6;
+        host: StandardHost6;
+    connections:
+        router.ethg++ <--> ethline <--> host.ethg++;
+}
+
+%#--------------------------------------------------------------------------------------------------------------
+%inifile: omnetpp.ini
+
+[General]
+network = TentativeRouterAdvertisementTest
+ned-path = .;../../../../src
+sim-time-limit = 3s
+record-vector-results = false
+cmdenv-express-mode = false
+
+**.router.ipv6.neighbourDiscovery.minIntervalBetweenRAs = 0.03s
+**.router.ipv6.neighbourDiscovery.maxIntervalBetweenRAs = 0.07s
+
+**.router.ipv6.neighbourDiscovery.cmdenv-log-level = info
+**.cmdenv-log-level = off
+
+%#--------------------------------------------------------------------------------------------------------------
+%contains-regex: stdout
+DAD completed for address fe80::[0-9a-f:]+ on eth0, address is unique[\s\S]*Create and send RA invoked!
+%#--------------------------------------------------------------------------------------------------------------
+%not-contains-regex: stdout
+Create and send RA invoked![\s\S]*DAD completed for address fe80
+%#--------------------------------------------------------------------------------------------------------------
+%not-contains: stdout
+<!> Error
+%#--------------------------------------------------------------------------------------------------------------