From 050a5d10e810321b7999961030c5c8e09ae9bba2 Mon Sep 17 00:00:00 2001 From: Fedja Beader Date: Tue, 23 Oct 2018 18:04:33 +0200 Subject: Move MAC address parts into its own document, signal that modifying it is optional and in addition tell users how to do so in their operating system. --- docs/gnulinux/grub_cbfs.md | 2 +- docs/hardware/mac_address.md | 99 +++++++++++++++++++++++++++++++++++++++++++ docs/install/r400_external.md | 10 +---- docs/install/t400_external.md | 10 +---- docs/install/t500_external.md | 10 +---- docs/install/x200_external.md | 11 +---- 6 files changed, 104 insertions(+), 38 deletions(-) create mode 100644 docs/hardware/mac_address.md (limited to 'docs') diff --git a/docs/gnulinux/grub_cbfs.md b/docs/gnulinux/grub_cbfs.md index 2e68cb0b..fc46180c 100644 --- a/docs/gnulinux/grub_cbfs.md +++ b/docs/gnulinux/grub_cbfs.md @@ -262,7 +262,7 @@ Then, add the new one to the ROM: $ ./cbfstool libreboot.rom add -n grubtest.cfg -f grubtest.cfg -t raw -#### Change MAC address in ROM +#### Change MAC address in ROM {#changeMAC} The last step before flashing the new ROM, is to change the MAC address inside it. Every libreboot ROM image contains a generic MAC address; you want to make sure that your ROM image contains yours, so as to not create any problems on your network diff --git a/docs/hardware/mac_address.md b/docs/hardware/mac_address.md new file mode 100644 index 00000000..43ca1d2b --- /dev/null +++ b/docs/hardware/mac_address.md @@ -0,0 +1,99 @@ +--- +title: Changing the MAC address +... + +Introduction (GM45) +=================== + +On all laptops with the GM45 chipset (T400,R400,T500,X200,X200S,X200T), +the [MAC address](https://en.wikipedia.org/wiki/MAC_address) +for the built-in gigabit ethernet controller is stored inside the flash chip, +along with Libreboot and other configuration data. + +Prebuilt Libreboot for these laptops contains a generic +MAC address in the configuration section. This address is `00:f5:f0:40:71:fe` +in builds before 2018-01-16 and `00:4c:69:62:72:65` afterwards. +Unless you change it, your computer will boot and use it. This can lead +to network problems if you have more than one Libreboot computer on +the same layer2 network (e.g. on the same network switch). + +To prevent these address clashes, you can either modify prebuilt Libreboot +to use an address of your own choosing or you can change the address in your +operating system's boot scripts. + +In either case, it is a good idea to write down the address that your +computer originally had. + +Obtaining the existing MAC address +================================== + +The existing MAC address may be obtained by the following methods: + +1. Read the white label on the bottom of the case. Note that this will only + produce the correct address, if your motherboard has never been replaced. + Examples: + + ![](../install/images/t400/macaddress0.jpg) + ![](../install/images/t400/macaddress1.jpg) + ![](../install/images/x200/disassembly/0002.jpg) + ![](../install/images/x200/disassembly/0001.jpg) + +2. Run `ip link` or `ifconfig` in a terminal/console/shell; + look for your ethernet device (e.g., **enpXXX** in Arch-based distributions, + or **eth0** in Debian-based distributions), + and look for a set of colon-delimited hexadecimal (base 16) digits: + 0,1,2,3,4,5,6,7,8,9,aA,bB,cC,dD,eE,fF. For example: `00:f3:f0:45:91:fe`. + + * `$ ip link` + + `... link/ether ??:??:??:??:??:?? brd ...` + + * Alternatively: + + `$ ifconfig` + + `... ether ??:??:??:??:??:?? txqueuelen ...` + + +Changing the MAC address in the operating system +================================================ + +There are three portable ways of doing so: + +1. Using the new iproute2 package: + + `# ip link set down` + + `# ip link set dev address 00:4c:69:62:72:65` + + `# ip link set up` + + +2. Using the old `ifconfig` command: + + `# ifconfig hw ether 00:4c:69:62:72:65` + + +3. Using the macchanger package. + +You can use use of these three methods in your operating system's +init scripts or you can use your operating system's own networking +configuration. Refer to your operating system's documentation for +how to do this. + +Changing the MAC address in Libreboot +===================================== + +See [here](../gnulinux/grub_cbfs.md#changeMAC). + + + +Copyright © 2017 Fedja Beader + +Copyright © 2014, 2015 Leah Rowe + +Permission is granted to copy, distribute and/or modify this document +under the terms of the GNU Free Documentation License Version 1.3 or any later +version published by the Free Software Foundation +with no Invariant Sections, no Front Cover Texts, and no Back Cover Texts. +A copy of this license is found in [../fdl-1.3.md](../fdl-1.3.md) diff --git a/docs/install/r400_external.md b/docs/install/r400_external.md index 4036c761..8f9dd1ff 100644 --- a/docs/install/r400_external.md +++ b/docs/install/r400_external.md @@ -69,15 +69,7 @@ Use this to find out: MAC address {#macaddress} =========== -On the R400, the MAC address for the onboard gigabit ethernet chipset is -stored inside the flash chip, along with other configuration data. - -Keep a note of the MAC address before disassembly; this is very -important, because you will need to insert this into the libreboot ROM -image before flashing it. It will be written in one of these locations: - -![](images/t400/macaddress0.jpg) ![](images/t400/macaddress1.jpg) -![](images/x200/disassembly/0001.jpg) +Refer to [mac\_address.md](../hardware/mac_address.md). Initial BBB configuration ========================= diff --git a/docs/install/t400_external.md b/docs/install/t400_external.md index 672ea46e..d377d4c0 100644 --- a/docs/install/t400_external.md +++ b/docs/install/t400_external.md @@ -70,15 +70,7 @@ Use this to find out: MAC address {#macaddress} =========== -On the T400, the MAC address for the onboard gigabit ethernet chipset is -stored inside the flash chip, along with other configuration data. - -Keep a note of the MAC address before disassembly; this is very -important, because you will need to insert this into the libreboot ROM -image before flashing it. It will be written in one of these locations: - -![](images/t400/macaddress0.jpg) ![](images/t400/macaddress1.jpg) -![](images/x200/disassembly/0001.jpg) +Refer to [mac\_address.md](../hardware/mac_address.md). Initial BBB configuration ========================= diff --git a/docs/install/t500_external.md b/docs/install/t500_external.md index 9e114bca..2a29d8ed 100644 --- a/docs/install/t500_external.md +++ b/docs/install/t500_external.md @@ -73,15 +73,7 @@ Use this to find out: MAC address {#macaddress} =========== -On the T500, the MAC address for the onboard gigabit ethernet chipset is -stored inside the flash chip, along with other configuration data. - -Keep a note of the MAC address before disassembly; this is very -important, because you will need to insert this into the libreboot ROM -image before flashing it. It will be written in one of these locations: - -![](images/t400/macaddress0.jpg) ![](images/t400/macaddress1.jpg) -![](images/x200/disassembly/0001.jpg) +Refer to [mac\_address.md](../hardware/mac_address.md). Initial BBB configuration ========================= diff --git a/docs/install/x200_external.md b/docs/install/x200_external.md index 83a5c23f..c7330ce9 100644 --- a/docs/install/x200_external.md +++ b/docs/install/x200_external.md @@ -28,16 +28,7 @@ supported; see the [hardware](../hardware/x200.html#x200s) page. MAC address =========== -On the X200/X200S/X200T, the MAC address for the onboard gigabit -ethernet chipset is stored inside the flash chip, along with other -configuration data. - -Keep a note of the MAC address before disassembly; this is very -important, because you will need to insert this into the libreboot ROM -image before flashing it. It will be written in one of these locations: - -![](images/x200/disassembly/0002.jpg) -![](images/x200/disassembly/0001.jpg) +Refer to [mac\_address.md](../hardware/mac_address.md). Initial BBB configuration ========================= -- cgit v1.2.3-70-g09d2