inet-framework · adamgeorge309 · Sep 2, 2026
diff --git a/src/inet/networklayer/icmpv6/Ipv6NeighbourDiscovery.cc b/src/inet/networklayer/icmpv6/Ipv6NeighbourDiscovery.cc
@@ -1010,10 +1010,17 @@ void Ipv6NeighbourDiscovery::createAndSendRsPacket(NetworkInterface *ie)
     // or the unspecified address.
     Ipv6Address myIPv6Address = ie->getProtocolData<Ipv6InterfaceData>()->getPreferredAddress();
 
-    if (myIPv6Address.isUnspecified())
-        myIPv6Address = ie->getProtocolData<Ipv6InterfaceData>()->getLinkLocalAddress(); // so we use the link local address instead
-
-    if (ie->getProtocolData<Ipv6InterfaceData>()->isTentativeAddress(myIPv6Address))
+    // getPreferredAddress() returns the default source address for off-link destinations,
+    // and deliberately prefers a global address even while Duplicate Address Detection (DAD)
+    // is still running for it. A solicitation only has to reach the link-local all-routers
+    // multicast address, so fall back to the link-local address rather than straight to the
+    // unspecified address: a tentative address is not assigned to the interface yet
+    // (RFC 4862 Section 5.4), and Ipv6 would substitute it on transmission, releasing the
+    // solicitation with a source address that contradicts the option chosen below.
+    if (myIPv6Address.isUnspecified() || ie->getProtocolData<Ipv6InterfaceData>()->isTentativeAddress(myIPv6Address))
+        myIPv6Address = ie->getProtocolData<Ipv6InterfaceData>()->getLinkLocalAddress();
+
+    if (myIPv6Address.isUnspecified() || ie->getProtocolData<Ipv6InterfaceData>()->isTentativeAddress(myIPv6Address))
         myIPv6Address = Ipv6Address::UNSPECIFIED_ADDRESS;
 
     Ipv6Address destAddr = Ipv6Address::ALL_ROUTERS_2; // all_routers multicast

diff --git a/tests/fingerprint/examples.csv b/tests/fingerprint/examples.csv
@@ -380,9 +380,9 @@
 /examples/manetrouting/multiradio/,  -f omnetpp.ini -c MultiRadio -r 0,             20s,             ec17-5cc2/tplx;55f5-0894/~tNl, PASS,  wireless adhoc Ipv4
 /examples/manetrouting/multiradio/,  -f omnetpp.ini -c SingleRadio -r 0,            20s,             85a0-51b8/tplx;c07a-44e1/~tNl;3aa0-49ed/tyf, PASS,  wireless adhoc Ipv4
 
-/examples/ipv6/mipv6/,               -f omnetpp.ini -c Handover -r 0,                70s,             19b8-20a4/tplx;b378-071d/~tNl;d358-e3bb/~tND;44ef-1a45/tyf, PASS, wireless EthernetMac
-/examples/ipv6/mipv6/,               -f omnetpp.ini -c RouteOptimizationTwoCNs -r 0,  60s,             3f0c-078d/tplx;04e1-1f03/~tNl;4199-2b15/~tND;ed3e-17fa/tyf, PASS, wireless EthernetMac
-/examples/ipv6/mipv6roaming/,        -f omnetpp.ini -c Roaming -r 0,                 70s,             0798-40c2/tplx;a682-8d0e/~tNl;cdb7-1b34/~tND;afae-2b3c/tyf, PASS, wireless EthernetMac
+/examples/ipv6/mipv6/,               -f omnetpp.ini -c Handover -r 0,                70s,             43f0-699e/tplx;ff9a-8dbc/~tNl;9304-d5d5/~tND;44ef-1a45/tyf, PASS, wireless EthernetMac
+/examples/ipv6/mipv6/,               -f omnetpp.ini -c RouteOptimizationTwoCNs -r 0,  60s,             b457-5c37/tplx;4038-4ba8/~tNl;d2a0-90db/~tND;ed3e-17fa/tyf, PASS, wireless EthernetMac
+/examples/ipv6/mipv6roaming/,        -f omnetpp.ini -c Roaming -r 0,                 70s,             5272-c850/tplx;1d99-c152/~tNl;9ca1-b5ff/~tND;afae-2b3c/tyf, PASS, wireless EthernetMac
 /examples/ipv6/pmipv6/,              -f omnetpp.ini -c General -r 0,                 60s,             f614-da0d/tplx;8b55-7191/~tNl;b490-dc09/~tND;0277-d784/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,

diff --git a/tests/fingerprint/mipv6-refactoring.csv b/tests/fingerprint/mipv6-refactoring.csv
@@ -8,9 +8,9 @@
 # empty-shim step, which kept these fingerprints bit-for-bit identical.
 
 # MIPv6 example — the primary test
-/examples/ipv6/mipv6/,               -f omnetpp.ini -c Handover -r 0,                70s,            aa29-a8c5/~tNlb, PASS, wireless EthernetMac
-/examples/ipv6/mipv6/,               -f omnetpp.ini -c RouteOptimizationTwoCNs -r 0,  60s,            068b-23aa/~tNlb, PASS, wireless EthernetMac
-/examples/ipv6/mipv6roaming/,        -f omnetpp.ini -c Roaming -r 0,                 70s,            7ed8-bee3/~tNlb, PASS, wireless EthernetMac
+/examples/ipv6/mipv6/,               -f omnetpp.ini -c Handover -r 0,                70s,            9489-e81a/~tNlb, PASS, wireless EthernetMac
+/examples/ipv6/mipv6/,               -f omnetpp.ini -c RouteOptimizationTwoCNs -r 0,  60s,            f670-714f/~tNlb, PASS, wireless EthernetMac
+/examples/ipv6/mipv6roaming/,        -f omnetpp.ini -c Roaming -r 0,                 70s,            05e6-93d0/~tNlb, PASS, wireless EthernetMac
 
 # IPv6 examples
 # MLD example — new PASS row; ~tNl locks the MLD Report/Query/Done/MAS-Query packet exchange (traffic+lengths);

diff --git a/tests/module/Ipv6RouterSolicitation_SourceLinkLayerAddressOption.test b/tests/module/Ipv6RouterSolicitation_SourceLinkLayerAddressOption.test
@@ -0,0 +1,75 @@
+%description:
+Tests that a Router Solicitation whose IP source address is a real (not
+unspecified) address carries the Source Link-Layer Address option, even when
+Duplicate Address Detection (DAD) is still running for the host's global
+address at the moment the solicitation is sent.
+
+RFC 4861 Section 6.3.7: "A host sends Router Solicitations to the all-routers
+multicast address.  The IP source address is set to either one of the
+interface's unicast addresses or the unspecified address.  The Source
+Link-Layer Address option SHOULD be set to the host's link-layer address, if
+the IP source address is not the unspecified address."
+
+The router logs the link-layer address it extracts from each solicitation, so
+a missing option shows up as an all-zero MAC address.
+
+%#--------------------------------------------------------------------------------------------------------------
+%file: test.ned
+import inet.networklayer.configurator.ipv6.Ipv6NetworkConfigurator;
+import inet.node.ethernet.EthernetSwitch;
+import inet.node.ipv6.Router6;
+import inet.node.ipv6.StandardHost6;
+import ned.DatarateChannel;
+
+network RsSourceLinkLayerOptionNetwork
+{
+    types:
+        channel ethline extends DatarateChannel
+        {
+            delay = 0.1us;
+            datarate = 100Mbps;
+        }
+    submodules:
+        configurator: Ipv6NetworkConfigurator;
+        router: Router6;
+        switch: EthernetSwitch;
+        host[2]: StandardHost6;
+    connections:
+        router.ethg++ <--> ethline <--> switch.ethg++;
+        for i=0..1 {
+            host[i].ethg++ <--> ethline <--> switch.ethg++;
+        }
+}
+%#--------------------------------------------------------------------------------------------------------------
+%inifile: omnetpp.ini
+[General]
+record-vector-results = false
+ned-path = ../../../../src
+network = RsSourceLinkLayerOptionNetwork
+sim-time-limit = 10s
+cmdenv-express-mode = false
+cmdenv-log-prefix = "%C: "
+
+# Stateless address autoconfiguration: the configurator only hands out the prefix
+**.ipv6.configurator.networkConfiguratorModule = "configurator"
+*.configurator.assignAddressesToHosts = false
+*.configurator.config = xml("<config><interface among='host[*] router' prefix='2001:db8:1:1::/64'/></config>")
+
+# Advertise often, so that a host holds a tentative global address by the time
+# its own Router Solicitation is due
+*.router.ipv6.neighbourDiscovery.minIntervalBetweenRAs = 0.1s
+*.router.ipv6.neighbourDiscovery.maxIntervalBetweenRAs = 0.2s
+
+%#--------------------------------------------------------------------------------------------------------------
+%subst: /omnetpp:://
+%#--------------------------------------------------------------------------------------------------------------
+%not-contains: stdout
+MAC Address '00-00-00-00-00-00' extracted
+%#--------------------------------------------------------------------------------------------------------------
+%contains: stdout
+MAC Address '0A-AA-
+%#--------------------------------------------------------------------------------------------------------------
+%postrun-command: grep "undisposed object:" test.out > test_undisposed.out || true
+%not-contains: test_undisposed.out
+undisposed object: (
+%#--------------------------------------------------------------------------------------------------------------