Extract IP/MPLS/IPv6 MTU from ZTE interface detail.

Plain MTU alone missed sibling values in filtered show interface output; also clear Filldown between interfaces so optional IPv6 MTU does not leak.

Co-authored-by: Cursor <cursoragent@cursor.com>

netx_api/biz_state/parsers/zte/interface_detail.py

@@ -18,6 +18,9 @@ _IF_HDR_RE = re.compile(
 )
 _DESC_RE = re.compile(r"^\s*Description:\s*(?P<desc>.*?)\s*$", re.I)
 _BW_RE = re.compile(r"^\s*BW\s+(?P<bw>.+?)\s*$", re.I)
+_IP_MTU_RE = re.compile(r"^\s*IP\s+MTU\s+(?P<mtu>\d+)\s+bytes", re.I)
+_IPV6_MTU_RE = re.compile(r"^\s*IPv6\s+MTU\s+(?P<mtu>\d+)\s+bytes", re.I)
+_MPLS_MTU_RE = re.compile(r"^\s*MPLS\s+MTU\s+(?P<mtu>\d+)\s+bytes", re.I)
 _MTU_RE = re.compile(r"^\s*MTU\s+(?P<mtu>\d+)\s+bytes", re.I)
 _MEDIA_RE = re.compile(r"^\s*The\s+port\s+is\s+(?P<media>\S+)", re.I)
 _NEG_RE = re.compile(r"^\s*Negotiation\s+(?P<neg>\S+)", re.I)
@@ -39,7 +42,10 @@ def _empty_row(iface: str) -> dict[str, Any]:
         "port_media": "",
         "negotiation": "",
         "bw": "",
+        "ip_mtu": "",
         "mtu": "",
+        "mpls_mtu": "",
+        "ipv6_mtu": "",
         "rate_period": "",
         "input_bps": "",
         "output_bps": "",
@@ -82,7 +88,10 @@ def _map_fsm_rows(rows: list[dict[str, Any]]) -> list[dict[str, Any]]:
                 "port_media": row_get(r, "PORT_MEDIA", "port_media")[:32],
                 "negotiation": row_get(r, "NEGOTIATION", "negotiation")[:32],
                 "bw": row_get(r, "BW_RAW", "bw")[:64],
+                "ip_mtu": row_get(r, "IP_MTU", "ip_mtu")[:16],
                 "mtu": row_get(r, "MTU", "mtu")[:16],
+                "mpls_mtu": row_get(r, "MPLS_MTU", "mpls_mtu")[:16],
+                "ipv6_mtu": row_get(r, "IPV6_MTU", "ipv6_mtu")[:16],
                 "rate_period": row_get(r, "RATE_PERIOD", "rate_period")[:16],
                 "input_bps": row_get(r, "INPUT_BPS", "input_bps")[:32],
                 "output_bps": row_get(r, "OUTPUT_BPS", "output_bps")[:32],
@@ -136,6 +145,18 @@ def _hand_parse(*, raw_text: str, **_kw: Any) -> list[dict[str, Any]]:
         if m:
             cur["bw"] = m.group("bw").strip()[:64]
             continue
+        m = _IP_MTU_RE.match(line)
+        if m:
+            cur["ip_mtu"] = m.group("mtu")[:16]
+            continue
+        m = _IPV6_MTU_RE.match(line)
+        if m:
+            cur["ipv6_mtu"] = m.group("mtu")[:16]
+            continue
+        m = _MPLS_MTU_RE.match(line)
+        if m:
+            cur["mpls_mtu"] = m.group("mtu")[:16]
+            continue
         m = _MTU_RE.match(line)
         if m:
             cur["mtu"] = m.group("mtu")[:16]

netx_api/biz_state/profiles.py

@@ -223,7 +223,10 @@ _IFACE_DETAIL_FIELDS: list[FieldDef] = [
     FieldDef("in_util", length=16, role="counter", display_name="In Util%"),
     FieldDef("out_util", length=16, role="counter", display_name="Out Util%"),
     FieldDef("bw", length=64, role="meta", display_name="BW"),
+    FieldDef("ip_mtu", length=16, role="meta", display_name="IP MTU"),
     FieldDef("mtu", length=16, role="meta", display_name="MTU"),
+    FieldDef("mpls_mtu", length=16, role="meta", display_name="MPLS MTU"),
+    FieldDef("ipv6_mtu", length=16, role="meta", display_name="IPv6 MTU"),
     FieldDef("ifindex", length=32, role="meta", display_name="ifindex"),
     FieldDef("description", length=256, role="meta", display_name="描述"),
     FieldDef("port_media", length=32, role="meta", display_name="Media"),

netx_api/cli_templates/zte/zte_zxros_show_interface.textfsm

@@ -5,7 +5,10 @@ Value Filldown DESCRIPTION (.+?)
 Value Filldown PORT_MEDIA (\S+)
 Value Filldown NEGOTIATION (\S+)
 Value Filldown BW_RAW (\d+(?:\.\d+)?\s*[kKmMgGtT]?\s*(?:G?bit|bit)/s(?:ec)?)
+Value Filldown IP_MTU (\d+)
 Value Filldown MTU (\d+)
+Value Filldown MPLS_MTU (\d+)
+Value Filldown IPV6_MTU (\d+)
 Value Filldown RATE_PERIOD (\d+)
 Value Filldown INPUT_BPS ([\d.]+)
 Value Filldown OUTPUT_BPS ([\d.]+)
@@ -13,11 +16,15 @@ Value IN_UTIL ([\d.]+)
 Value OUT_UTIL ([\d.]+)
 
 Start
+  ^${IFNAME}\s+is\s+${ADMIN_STATE}(?:,\s*ifindex:\s*${IFINDEX})? -> Continue.Clearall
   ^${IFNAME}\s+is\s+${ADMIN_STATE}(?:,\s*ifindex:\s*${IFINDEX})?
   ^\s*Description:\s*${DESCRIPTION}\s*$$
   ^\s*The\s+port\s+is\s+${PORT_MEDIA}
   ^\s*Negotiation\s+${NEGOTIATION}
   ^\s*BW\s+${BW_RAW}
+  ^\s*IP\s+MTU\s+${IP_MTU}\s+bytes
+  ^\s*IPv6\s+MTU\s+${IPV6_MTU}\s+bytes
+  ^\s*MPLS\s+MTU\s+${MPLS_MTU}\s+bytes
   ^\s*MTU\s+${MTU}\s+bytes
   ^\s*Rate\s+period\s*:\s*${RATE_PERIOD}\s*s -> Rates
   ^\s*$$
@@ -28,12 +35,14 @@ Rates
   ^\s*Output\s*:\s*${OUTPUT_BPS}\s*bit/s
   ^\s*Peak\s+rate: -> AfterPeak
   ^\s*Intf\s+utilization:\s*input\s*${IN_UTIL}%\s+output\s*${OUT_UTIL}% -> Record Start
-  ^${IFNAME}\s+is\s+${ADMIN_STATE}(?:,\s*ifindex:\s*${IFINDEX})? -> Clearall Start
+  ^${IFNAME}\s+is\s+${ADMIN_STATE}(?:,\s*ifindex:\s*${IFINDEX})? -> Continue.Clearall
+  ^${IFNAME}\s+is\s+${ADMIN_STATE}(?:,\s*ifindex:\s*${IFINDEX})? -> Start
   ^\s*$$
   ^.* -> Rates
 
 AfterPeak
   ^\s*Intf\s+utilization:\s*input\s*${IN_UTIL}%\s+output\s*${OUT_UTIL}% -> Record Start
-  ^${IFNAME}\s+is\s+${ADMIN_STATE}(?:,\s*ifindex:\s*${IFINDEX})? -> Clearall Start
+  ^${IFNAME}\s+is\s+${ADMIN_STATE}(?:,\s*ifindex:\s*${IFINDEX})? -> Continue.Clearall
+  ^${IFNAME}\s+is\s+${ADMIN_STATE}(?:,\s*ifindex:\s*${IFINDEX})? -> Start
   ^\s*$$
   ^.* -> AfterPeak

tests/test_zte_extended_parsers.py

@@ -265,7 +265,9 @@ gei-0/0/0/1 is up, ifindex: 100
   The port is optical
   Negotiation force
   BW 1 Gbit/s
+  IP MTU 1500 bytes
   MTU 1600 bytes
+  MPLS MTU 1550 bytes
   Rate period     : 120 s
    Input          : 100 bit/s              1 packet/s
    Output         : 200 bit/s              2 packet/s
@@ -276,7 +278,10 @@ gei-0/0/0/1 is up, ifindex: 100
 gei-0/0/0/2 is administratively down, ifindex: 101
   Description: spare
   BW 1 Gbit/s
-  MTU 1500 bytes
+  IP MTU 8978 bytes
+  MTU 9000 bytes
+  IPv6 MTU 8978 bytes
+  MPLS MTU 8978 bytes
   Rate period     : 120 s
    Input          : 0 bit/s              0 packet/s
    Output         : 0 bit/s              0 packet/s
@@ -292,7 +297,47 @@ gei-0/0/0/2 is administratively down, ifindex: 101
         self.assertEqual(rows[0]["admin"], "up")
         self.assertEqual(rows[0]["input_bps"], "100")
         self.assertEqual(rows[0]["out_util"], "2")
+        self.assertEqual(rows[0]["ip_mtu"], "1500")
+        self.assertEqual(rows[0]["mtu"], "1600")
+        self.assertEqual(rows[0]["mpls_mtu"], "1550")
+        self.assertEqual(rows[0]["ipv6_mtu"], "")
         self.assertEqual(rows[1]["admin"], "admin-down")
+        self.assertEqual(rows[1]["ip_mtu"], "8978")
+        self.assertEqual(rows[1]["mtu"], "9000")
+        self.assertEqual(rows[1]["ipv6_mtu"], "8978")
+        self.assertEqual(rows[1]["mpls_mtu"], "8978")
+
+        # No IPv6 MTU on second iface — must not inherit from previous Filldown.
+        leak_sample = """
+gei-0/0/0/1 is up, ifindex: 1
+  IP MTU 1500 bytes
+  MTU 1600 bytes
+  IPv6 MTU 8978 bytes
+  MPLS MTU 1550 bytes
+  Rate period     : 120 s
+   Input          : 1 bit/s
+   Output         : 2 bit/s
+  Intf utilization: input 1%             output 2%
+gei-0/0/0/2 is up, ifindex: 2
+  IP MTU 1500 bytes
+  MTU 1600 bytes
+  MPLS MTU 1550 bytes
+  Rate period     : 120 s
+   Input          : 0 bit/s
+   Output         : 0 bit/s
+  Intf utilization: input 0%             output 0%
+"""
+        leak_rows = normalize_interface_detail(
+            raw_text=leak_sample,
+            vendor="zte",
+            device_type="zte_zxros",
+            command="show interface",
+        )
+        self.assertEqual(len(leak_rows), 2)
+        self.assertEqual(leak_rows[0]["ipv6_mtu"], "8978")
+        self.assertEqual(leak_rows[1]["ipv6_mtu"], "")
+        self.assertEqual(leak_rows[1]["ip_mtu"], "1500")
+        self.assertEqual(leak_rows[1]["mpls_mtu"], "1550")
 
         cmd = (
             "show interface | include ifindex|BW|The port is|MTU|Negotiation|"
@@ -302,6 +347,8 @@ gei-0/0/0/2 is administratively down, ifindex: 101
         self.assertIsNotNone(hit)
         assert hit is not None
         self.assertEqual(hit.profile.profile_id, "zte.interface_detail")
+        field_names = {f.name for f in hit.profile.fields}
+        self.assertTrue({"ip_mtu", "mtu", "mpls_mtu", "ipv6_mtu"} <= field_names)
 
         hit6 = match_command(
             vendor_key="zte",