use wireshark to examine ethernet frames topology

IEEE 802.1Q: IEEE Standards for local and metropolitan area networks-Virtual Bridged Local Area Networks (for MSTP).If you find yourself troubleshooting network issues, and you have to inspect individual packets, you need to use Wireshark. IEEE 802.1D: IEEE standard for local and metropolitan area networks–Media access control (MAC) Bridges (for STP and RSTP). Show only the STP based traffic: stp Capture FilterĬapture only the STP based traffic: stp External links Example capture fileĪ complete list of STP display filter fields can be found in the display filter reference

There are no STP specific preference settings. Type (only PVID type 0x00 is supported): 2 bytes.Even byte padding (802.1D only): 1 byte.It should be noted that only 802.1D and not RST BPDUs include the one padding byte for alignment. The extension at the end of the BPDU advertises the VLAN ID (PVID) that the BPDU was sent on. The extension is added to 802.1D and RST BPDUs sent on 802.1Q VLAN trunks. Also add info of additional Wireshark features where appropriate, like special statistics of this protocol.Ĭisco has a custom TLV extension called Per Vlan Spanning Tree (PVST+). The STP dissector is fully functional and supports IEEE 802.1D BPDU, Rapid Spanning-Tree BPDUs, and MST/MSTI BPDUs. LLC: Typically, STP uses 802.2 LLC as its transport protocol, running on link-layer protocols in the LanProtocolFamily such as Ethernet.

As the name suggests, it creates a spanning tree within a mesh network of connected layer-2 bridges (typically Ethernet switches), and disables those links that are not part of the spanning tree, leaving a single active path between any two network nodes. The Spanning Tree Protocol ( STP) is a network protocolthat ensures a loop-free topology for any bridged Ethernet local area network.

Use wireshark to examine ethernet frames topology