From: Guy Harris <guy@alum.mit.edu>
Date: Sun, 14 Apr 2013 01:45:19 +0000 (-0700)
Subject: There's another Cisco-private encapsulation of BPDUs.
X-Git-Url: https://git.tcpdump.org/tcpdump/commitdiff_plain/d54325c0e2c85bbc537869b8fdc43fba7736c174

There's another Cisco-private encapsulation of BPDUs.

At least according to the Wireshark STP dissector, SNAP frames with the
Cisco OUI and a PID of 0x010c contain BPDUs, for "VLAN Bridge".
---

diff --git a/llc.h b/llc.h
index faa72561..66046699 100644
--- a/llc.h
+++ b/llc.h
@@ -106,6 +106,7 @@
 #define	PID_CISCO_DTP		0x2004	/* Cisco Dynamic Trunk Protocol */
 #define	PID_CISCO_UDLD		0x0111	/* Unidirectional Link Detection */
 #define	PID_CISCO_PVST		0x010b	/* Per VLAN Spanning Tree+ and RPVST+ */
+#define	PID_CISCO_VLANBRIDGE	0x010c	/* "VLAN Bridge", according to Wireshark */
 
 /*
  * PIDs for use with OUI_RFC2684.
diff --git a/print-llc.c b/print-llc.c
index a1934715..5ba81894 100644
--- a/print-llc.c
+++ b/print-llc.c
@@ -107,6 +107,7 @@ static const struct tok cisco_values[] = {
 	{ PID_CISCO_DTP, "DTP" },
 	{ PID_CISCO_UDLD, "UDLD" },
 	{ PID_CISCO_PVST, "PVST" },
+	{ PID_CISCO_VLANBRIDGE, "VLAN Bridge" },
 	{ 0,             NULL }
 };
 
@@ -453,6 +454,7 @@ snap_print(const u_char *p, u_int length, u_int caplen, u_int bridge_pad)
                         vtp_print(p, length);
                         return (1);
                 case PID_CISCO_PVST:
+                case PID_CISCO_VLANBRIDGE:
                         stp_print(p, length);
                         return (1);
                 default: