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Diffstat (limited to 'plugin/debug/README.md')
| -rw-r--r-- | plugin/debug/README.md | 21 |
1 files changed, 20 insertions, 1 deletions
diff --git a/plugin/debug/README.md b/plugin/debug/README.md index 5c97e004e..0ce1808ed 100644 --- a/plugin/debug/README.md +++ b/plugin/debug/README.md @@ -10,7 +10,7 @@ Normally CoreDNS will recover from panics, using *debug* inhibits this. The main to help testing. A side effect of using *debug* is that `log.Debug` and `log.Debugf` will be printed to standard output. -Note that the *errors* plugin (if loaded) will also set a `recover` negating this setting. +Note that the *errors* plugin (if loaded) will also set a `recover` negating this setting. ## Syntax @@ -18,6 +18,21 @@ Note that the *errors* plugin (if loaded) will also set a `recover` negating thi debug ~~~ +Some plugin will debug log DNS messages. This is done in the following format: + +~~~ +debug: 000000 00 0a 01 00 00 01 00 00 00 00 00 01 07 65 78 61 +debug: 000010 6d 70 6c 65 05 6c 6f 63 61 6c 00 00 01 00 01 00 +debug: 000020 00 29 10 00 00 00 80 00 00 00 +debug: 00002a +~~~ + +Using `text2pcap` (part of Wireshark) this can be converted back to binary, with the following +command line: `text2pcap -i 17 -u 53,53`. Where 17 is the protocol (UDP) and 53 are the ports. These +ports allow wireshark to detect these packets as DNS messages. + +Each plugin can decide to dump messages to aid in debugging. + ## Examples Disable the ability to recover from crashes and show debug logging: @@ -27,3 +42,7 @@ Disable the ability to recover from crashes and show debug logging: debug } ~~~ + +## Also See + +https://www.wireshark.org/docs/man-pages/text2pcap.html. |