Added an info message for the highest milestone

CHANGELOG.md

@@ -12,5 +12,6 @@
 - Added `--p2p-static-peers-url` option to read static peers from a URL or file
 - Added node epoch and computed slot to the sync committee duties failure message for more context about the failure condition.
 - Updated third party libraries.
+- Added an info message on startup for the highest supported milestone and associated epoch.
 
 ### Bug Fixes

ethereum/spec/src/main/java/tech/pegasys/teku/spec/Spec.java

@@ -35,6 +35,8 @@
 import java.util.function.Function;
 import java.util.function.Supplier;
 import javax.annotation.CheckReturnValue;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.apache.tuweni.bytes.Bytes;
 import org.apache.tuweni.bytes.Bytes32;
 import tech.pegasys.teku.bls.BLSPublicKey;
@@ -106,6 +108,7 @@
 import tech.pegasys.teku.spec.schemas.registry.SchemaRegistryBuilder;
 
 public class Spec {
+  private static final Logger LOG = LogManager.getLogger();
   private final Map<SpecMilestone, SpecVersion> specVersions;
   private final ForkSchedule forkSchedule;
   private final StateTransition stateTransition;
@@ -144,6 +147,13 @@ static Spec create(
 
     final ForkSchedule forkSchedule = forkScheduleBuilder.build();
 
+    final UInt64 lastForkActivationEpoch =
+        forkSchedule.getActiveMilestones().getLast().getFork().getEpoch();
+    LOG.info(
+        "Creating network specification. Highest milestone supported: {}, from epoch {}",
+        highestMilestoneSupported.lowerCaseName(),
+        lastForkActivationEpoch);
+
     return new Spec(specConfigAndParent, specVersions, forkSchedule);
   }
 

ethereum/spec/src/test/java/tech/pegasys/teku/spec/SpecFactoryTest.java

@@ -0,0 +1,107 @@
+/*
+ * Copyright Consensys Software Inc., 2025
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on
+ * an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations under the License.
+ */
+
+package tech.pegasys.teku.spec;
+
+import static org.assertj.core.api.AssertionsForClassTypes.assertThat;
+import static org.assertj.core.api.AssertionsForClassTypes.assertThatThrownBy;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.TestTemplate;
+import tech.pegasys.teku.infrastructure.unsigned.UInt64;
+import tech.pegasys.teku.spec.config.SpecConfig;
+import tech.pegasys.teku.spec.config.SpecConfigAndParent;
+import tech.pegasys.teku.spec.config.SpecConfigLoader;
+
+@TestSpecContext(allMilestones = true)
+class SpecFactoryTest {
+  private static final Logger LOG = LogManager.getLogger();
+  private SpecMilestone milestone;
+  private TestSpecInvocationContextProvider.SpecContext specContext;
+
+  @BeforeEach
+  void setup(final TestSpecInvocationContextProvider.SpecContext specContext) {
+    this.milestone = specContext.getSpecMilestone();
+    this.specContext = specContext;
+  }
+
+  @TestTemplate
+  void shouldSetHighestSupportedMilestone() {
+    final UInt64 forkEpoch = UInt64.valueOf(1);
+    final SpecConfigAndParent<? extends SpecConfig> config =
+        SpecConfigLoader.loadConfig(
+            specContext.getNetwork().configName(),
+            builder -> {
+              switch (milestone) {
+                case PHASE0 -> LOG.info("PHASE0");
+                case ALTAIR -> builder.altairBuilder(a -> a.altairForkEpoch(forkEpoch));
+                case BELLATRIX ->
+                    builder
+                        .altairBuilder(a -> a.altairForkEpoch(UInt64.ZERO))
+                        .bellatrixBuilder(b -> b.bellatrixForkEpoch(forkEpoch));
+                case CAPELLA ->
+                    builder
+                        .altairBuilder(a -> a.altairForkEpoch(UInt64.ZERO))
+                        .bellatrixBuilder(b -> b.bellatrixForkEpoch(UInt64.ZERO))
+                        .capellaBuilder(c -> c.capellaForkEpoch(forkEpoch));
+                case DENEB ->
+                    builder
+                        .altairBuilder(a -> a.altairForkEpoch(UInt64.ZERO))
+                        .bellatrixBuilder(b -> b.bellatrixForkEpoch(UInt64.ZERO))
+                        .capellaBuilder(c -> c.capellaForkEpoch(UInt64.ZERO))
+                        .denebBuilder(d -> d.denebForkEpoch(forkEpoch));
+                case ELECTRA ->
+                    builder
+                        .altairBuilder(a -> a.altairForkEpoch(UInt64.ZERO))
+                        .bellatrixBuilder(b -> b.bellatrixForkEpoch(UInt64.ZERO))
+                        .capellaBuilder(c -> c.capellaForkEpoch(UInt64.ZERO))
+                        .denebBuilder(d -> d.denebForkEpoch(UInt64.ZERO))
+                        .electraBuilder(e -> e.electraForkEpoch(forkEpoch));
+                case FULU ->
+                    builder
+                        .altairBuilder(a -> a.altairForkEpoch(UInt64.ZERO))
+                        .bellatrixBuilder(b -> b.bellatrixForkEpoch(UInt64.ZERO))
+                        .capellaBuilder(c -> c.capellaForkEpoch(UInt64.ZERO))
+                        .denebBuilder(d -> d.denebForkEpoch(UInt64.ZERO))
+                        .electraBuilder(e -> e.electraForkEpoch(UInt64.ZERO))
+                        .fuluBuilder(f -> f.fuluForkEpoch(forkEpoch));
+                default ->
+                    throw new IllegalStateException(
+                        "Unhandled fork transition for test "
+                            + specContext.getDisplayName()
+                            + ": "
+                            + milestone);
+              }
+            });
+    final Spec testSpec = SpecFactory.create(config);
+    for (SpecMilestone currentMilestone : SpecMilestone.getAllPriorMilestones(milestone)) {
+      LOG.info("Previous milestone " + currentMilestone);
+      assertThat(testSpec.getForkSchedule().getFork(currentMilestone).getEpoch())
+          .isEqualTo(UInt64.ZERO);
+    }
+    LOG.info("Highest milestone supported " + milestone);
+    assertThat(testSpec.atEpoch(forkEpoch).getMilestone()).isEqualTo(milestone);
+
+    for (SpecMilestone currentMilestone : SpecMilestone.getAllMilestonesFrom(milestone)) {
+      if (currentMilestone == milestone) {
+        continue;
+      }
+      LOG.info("Undefined milestone " + currentMilestone);
+      assertThatThrownBy(() -> testSpec.getForkSchedule().getFork(currentMilestone))
+          .isInstanceOf(IllegalArgumentException.class)
+          .hasMessageContaining("not a part of fork schedule");
+    }
+  }
+}

teku/src/main/java/tech/pegasys/teku/AbstractNode.java

@@ -175,8 +175,7 @@ private void reportBellatrixMergeOverrides(final TekuConfiguration tekuConfig) {
       reportTerminalBlockHashOverride = true;
       reportTerminalBlockHashEpochOverride = true;
     } else {
-      final Eth2NetworkConfiguration defaultConfiguration =
-          Eth2NetworkConfiguration.builder().applyNetworkDefaults(maybeEth2Network.get()).build();
+      final Eth2NetworkConfiguration defaultConfiguration = tekuConfig.eth2NetworkConfiguration();
       reportTerminalBlockHashOverride =
           !defaultConfiguration
               .getTerminalBlockHashOverride()