diff --git a/docs/features/marker-traffic-insight.md b/docs/features/marker-traffic-insight.md
index 04d638282..b275c02b7 100644
--- a/docs/features/marker-traffic-insight.md
+++ b/docs/features/marker-traffic-insight.md
@@ -340,6 +340,8 @@ direction relative to the capture node; see [Direction](#direction).
   filter, the pcap filename, and `MARK` signal routing — so rename is a delete + recreate,
   not a field update. PUT ignores the body `name`; the `{name}` path parameter identifies
   the target, and only `bpf / tag / color / enabled / highlight_duration` are changeable.
+  Names are 1–32 chars (`[A-Za-z0-9][A-Za-z0-9_.-]*`); inherited copies carry a `global-`
+  prefix, so their filter names reach ~39.
 - **`global` prefix reserved.** User-chosen names may not start with `global`; inherited
   markers are stored as `global-{definition_name}` so the two namespaces cannot collide.
   Omitting `name` on create yields an auto-generated, prefix-free name.
diff --git a/gns3server/compute/base_node.py b/gns3server/compute/base_node.py
index 76d543364..aaf3da9a1 100644
--- a/gns3server/compute/base_node.py
+++ b/gns3server/compute/base_node.py
@@ -1115,7 +1115,10 @@ class BaseNode:
         # marker definitions (inherit_marker). The prefix is only forbidden at the
         # user-facing schema layer, not at the uBridge boundary.
         _MARKER_NAME_RE = re.compile(r"^[A-Za-z0-9][A-Za-z0-9_.-]*$")
-        if not _MARKER_NAME_RE.match(name):
+        # Defense-in-depth vs hand-edited topology: the user-facing name is capped
+        # at 32 by the schema; inherited copies carry a ``global-`` prefix (≤ 39),
+        # so allow up to 48 here.
+        if not _MARKER_NAME_RE.match(name) or len(name) > 48:
             raise UbridgeError(f"Invalid marker name: {name!r}")
         cmd = 'bridge add_packet_filter {bridge} {name} mark "{bpf}"'.format(
             bridge=bridge_name, name=name, bpf=bpf
diff --git a/gns3server/schemas/controller/links.py b/gns3server/schemas/controller/links.py
index dd4b4ce5c..853293f8c 100644
--- a/gns3server/schemas/controller/links.py
+++ b/gns3server/schemas/controller/links.py
@@ -152,7 +152,7 @@ class MarkerCreate(BaseModel):
     name: Optional[str] = Field(
         None,
         pattern=r"^[A-Za-z0-9][A-Za-z0-9_.-]*$",
-        max_length=128,
+        max_length=32,
         description='Unique marker name on the link. Auto-generated when absent.',
     )
     bpf: str
@@ -236,7 +236,7 @@ class MarkerDefinitionCreate(BaseModel):
     name: Optional[str] = Field(
         None,
         pattern=r"^[A-Za-z0-9][A-Za-z0-9_.-]*$",
-        max_length=128,
+        max_length=32,
         description="Unique definition name. Auto-generated when absent.",
     )
     bpf: str
diff --git a/tests/api/routes/controller/test_markers.py b/tests/api/routes/controller/test_markers.py
index d9fc27b3b..53e57e7d9 100644
--- a/tests/api/routes/controller/test_markers.py
+++ b/tests/api/routes/controller/test_markers.py
@@ -105,6 +105,17 @@ class TestMarkerRoutes:
         )
         assert response.status_code == status.HTTP_422_UNPROCESSABLE_ENTITY
 
+    async def test_create_marker_name_too_long_rejected(self, app: FastAPI, client: AsyncClient, project: Project) -> None:
+
+        link = UDPLink(project)
+        project._links = {link.id: link}
+
+        response = await client.post(
+            app.url_path_for("create_marker", project_id=project.id, link_id=link.id),
+            json={"name": "x" * 33, "bpf": "icmp"},  # max_length is 32
+        )
+        assert response.status_code == status.HTTP_422_UNPROCESSABLE_ENTITY
+
     async def test_get_markers(self, app: FastAPI, client: AsyncClient, project: Project) -> None:
 
         link = UDPLink(project)