Differences

This shows you the differences between two versions of the page.

--- os:ios:vlan.dat [2016-12-11 22:40] – root
+++ os:ios:vlan.dat [2023-01-04 17:45] (current) – Manuel Frei
@@ Line 1: / Line 1: @@
-====== vlan.dat ======
+====== vlan.dat Internals ======
+I wrote a Python module/utility to parse vlan.dat files: https://github.com/frei-style/vlandat
+This page shows some information about the reverse engineering.
 ===== About the File =====
@@ Line 22: / Line 26: @@
   * [[http://www.cisco.com/c/en/us/support/docs/switches/catalyst-2940-series-switches/109304-manage-vlandat.html|Managing vlan.dat in Cisco Catalyst Switches Running Cisco IOS Software]]
+===== Influence of VTP Configuration =====
+>In VTP Server Mode, switch "saves VLAN configuration information in a file named vlan.dat in flash memory."
+>In VTP Client Mode, switch saves "VLAN information in RAM only, not stored in NVRAM or FLash memory; must be repopulated from a VTP server if switch is power-cycled."
+>In VTP Transparent Mode, switch saves VLAN configuration in NVRAM.
+//-- SWITCH (642-813) Student Guide Volume I//
 ===== Structure =====
@@ Line 66: / Line 80: @@
 | 0d9    | 1     | char    | Backup CRF Mode | 0 (disabled), 1 (enabled) | type must be trcrf |
 | 0da    | 1     | char    | Remote SPAN | 0 (disabled), 1 (enabled) | |
-| 0db    | 1     | char    | :?:         | :?:  | :?: I have no idea. I changed the value to 1 and 2 but I didn't notice some differences on the switch with the show command. |
+| 0db    | 1     | char    | :?:         | :?:  | :?: I have no idea. I changed the value to 1 and 2 but I didn't notice any differences on the switch with the show command. |
 ^ Following Stuff is yet unknown ^^^^^^
 | ...    | :?:   | :?:     | :?: | :?: | :?: Looks like garbage, will be harder to figure that out. |
@@ Line 156: / Line 170: @@
 === Garbage ===
-There is some garbage at the end of the file. Marco Rizzi ([[http://rizzitech.blogspot.ch/2010_08_01_archive.html|Playing with vlan.dat]]) assumes, that it's additional information about FDDI/Token Ring vlans. I think he's right.
+There is some garbage at the end of the file. Marco Rizzi ([[http://rizzitech.blogspot.ch/2010_08_01_archive.html|Playing with vlan.dat]], the blog post was deleted unfortunately. It's available via Web Archive: [[https://web.archive.org/web/20150115040419/http://rizzitech.blogspot.com/2010/08/playing-with-vlandat.html|WebArchive]]) assumes, that it's additional information about FDDI/Token Ring vlans. I think he's right.
 I deleted the vlan.dat and reloaded the switch to get this clean config: