|
|
# discard
|
|
|
|
|
|
The discard protocol allows a client to send arbitrary data to a server. The data is then silently dropped.
|
|
|
|
|
|
## History
|
|
|
|
|
|
The discard protocol is one of the first protocols implemented atop TCP and UDP; it is described in RFC 863.
|
|
|
|
|
|
## Protocol dependencies
|
|
|
|
|
|
- [TCP](/TCP): Typically, the discard protocol uses [TCP](/TCP) as its transport protocol, but it also uses UDP. The port for discard traffic is 9.
|
|
|
|
|
|
## Example traffic
|
|
|
|
|
|
No example is needed, since the protocol accepts any data and does not reply.
|
|
|
|
|
|
## Wireshark
|
|
|
|
|
|
No discard dissector exists; it would only mark the packet as a discard protocol packet in the summary.
|
|
|
|
|
|
## Example capture file
|
|
|
|
|
|
XXX - Add a simple example capture file to the [SampleCaptures](/SampleCaptures) page and link from here (see below). Keep this file short, it's also a good idea to gzip it to make it even smaller, as Wireshark can open gzipped files automatically.
|
|
|
|
|
|
- [SampleCaptures/Discard.pcap](uploads/__moin_import__/attachments/SampleCaptures/Discard.pcap "Upload new attachment \"Discard.pcap\"")
|
|
|
|
|
|
## Display Filter
|
|
|
|
|
|
A complete list of Discard display filter fields can be found in the [display filter reference](http://www.wireshark.org/docs/dfref/d/discard.html)
|
|
|
|
|
|
Show only the discard based traffic:
|
|
|
|
|
|
```
|
|
|
discard
|
|
|
```
|
|
|
|
|
|
## Capture Filter
|
|
|
|
|
|
You cannot directly filter discard while capturing. However, if you know the [TCP](/TCP) port used (see above), you can filter on that one.
|
|
|
|
|
|
Capture only the discard traffic over the default port (9):
|
|
|
|
|
|
```
|
|
|
tcp port 9
|
|
|
```
|
|
|
|
|
|
## External links
|
|
|
|
|
|
- [RFC 863](http://www.ietf.org/rfc/rfc863.txt) *Discard Protocol* - specification of the discard protocol.
|
|
|
|
|
|
## Discussion
|
|
|
|
|
|
---
|
|
|
|
|
|
Imported from https://wiki.wireshark.org/DiscardProtocol on 2020-08-11 23:13:33 UTC |