1 diff --git a/scapy/contrib/cdp.py b/scapy/contrib/cdp.py
2 index c8b7f106..7b1ff64d 100644
3 --- a/scapy/contrib/cdp.py
4 +++ b/scapy/contrib/cdp.py
5 @@ -102,7 +102,8 @@ def _CDPGuessPayloadClass(p, **kargs):
6 class CDPMsgGeneric(Packet):
7 name = "CDP Generic Message"
8 fields_desc = [ XShortEnumField("type", None, _cdp_tlv_types),
9 - FieldLenField("len", None, "val", "!H"),
10 + FieldLenField("len", None, "val", "!H",
11 + adjust=lambda pkt, x: x + 4),
12 StrLenField("val", "", length_from=lambda x:x.len - 4) ]
15 @@ -178,7 +179,8 @@ class CDPMsgAddr(CDPMsgGeneric):
16 class CDPMsgPortID(CDPMsgGeneric):
18 fields_desc = [ XShortEnumField("type", 0x0003, _cdp_tlv_types),
19 - FieldLenField("len", None, "iface", "!H"),
20 + FieldLenField("len", None, "iface", "!H",
21 + adjust=lambda pkt, x: x + 4),
22 StrLenField("iface", "Port 1", length_from=lambda x:x.len - 4) ]