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/hardware/mac_address.md | 99 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 99 insertions(+) create mode 100644 docs/hardware/mac_address.md (limited to 'docs/hardware') 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) -- cgit v1.2.3-70-g09d2 From 8461b3b7aff238a9f204f6df754076d26b661812 Mon Sep 17 00:00:00 2001 From: Fedja Beader Date: Fri, 26 Oct 2018 16:47:00 +0200 Subject: Reword the section on obtaining the MAC address and remove unnecessary images .. but do not unlink them --- docs/hardware/mac_address.md | 19 +++++++++---------- 1 file changed, 9 insertions(+), 10 deletions(-) (limited to 'docs/hardware') diff --git a/docs/hardware/mac_address.md b/docs/hardware/mac_address.md index 43ca1d2b..3bb966bb 100644 --- a/docs/hardware/mac_address.md +++ b/docs/hardware/mac_address.md @@ -29,16 +29,7 @@ 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; +1. 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: @@ -55,6 +46,14 @@ The existing MAC address may be obtained by the following methods: `... ether ??:??:??:??:??:?? txqueuelen ...` +2. Otherwise you can read the white label that is often found on the + motherboard under the memory sticks: + ![](../install/images/t400/macaddress1.jpg) + +3. The MAC address is usually listed on the laptop chassis as well. This one + will be incorrect if the motherboard was changed and the stickers were not + updated. + Changing the MAC address in the operating system ================================================ -- cgit v1.2.3-70-g09d2 From ffbfd79eb3f2c543ae817412566b5784950a119c Mon Sep 17 00:00:00 2001 From: Fedja Beader Date: Fri, 26 Oct 2018 17:04:24 +0200 Subject: Reword the GM45 introductory section on the MAC address page. --- docs/hardware/mac_address.md | 25 +++++++++++++++++-------- 1 file changed, 17 insertions(+), 8 deletions(-) (limited to 'docs/hardware') diff --git a/docs/hardware/mac_address.md b/docs/hardware/mac_address.md index 3bb966bb..41aea4ff 100644 --- a/docs/hardware/mac_address.md +++ b/docs/hardware/mac_address.md @@ -2,20 +2,29 @@ title: Changing the MAC address ... -Introduction (GM45) -=================== +Introduction (GM45+e1000) +========================= -On all laptops with the GM45 chipset (T400,R400,T500,X200,X200S,X200T), -the [MAC address](https://en.wikipedia.org/wiki/MAC_address) +This section is applicable to all laptops with the GM45 chipset that +use the e1000 ethernet controller: +X200, X200s, X200t (tablet), X301, T400, T400s, T500, W500, W700. +R500 is an exception to this and does not use the built-in e1000. + +On all these laptops, 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. +along with Libreboot and other configuration data. Therefore, installing +Libreboot will overwrite it. -Prebuilt Libreboot for these laptops contains a generic +Thus, for these laptops, prebuilt Libreboot already 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. +in builds before 2018-01-16 and `00:4c:69:62:72:65` (see the ascii character +set) 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). +the same layer2 network (e.g. on the same network switch). The switch +(postman) will simply not know who to deliver to as the MAC (house) addresses +will be the same. 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 -- cgit v1.2.3-70-g09d2 From 45697f29657134f2e1867c1547a54963d7ff980c Mon Sep 17 00:00:00 2001 From: Fedja Beader Date: Fri, 2 Nov 2018 18:27:28 +0100 Subject: Reword again --- docs/hardware/mac_address.md | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) (limited to 'docs/hardware') diff --git a/docs/hardware/mac_address.md b/docs/hardware/mac_address.md index 41aea4ff..0a0d3621 100644 --- a/docs/hardware/mac_address.md +++ b/docs/hardware/mac_address.md @@ -5,10 +5,10 @@ title: Changing the MAC address Introduction (GM45+e1000) ========================= -This section is applicable to all laptops with the GM45 chipset that -use the e1000 ethernet controller: -X200, X200s, X200t (tablet), X301, T400, T400s, T500, W500, W700. -R500 is an exception to this and does not use the built-in e1000. +This section is applicable to all Libreboot-supported laptops with the +mobile 4 series chipset (as shown in `$ lspci`) +that use the e1000 ethernet controller (e.g. T400, X200). +The R500 is an exception to this as it does not use the built-in e1000. On all these laptops, the [MAC address](https://en.wikipedia.org/wiki/MAC_address) @@ -39,10 +39,10 @@ Obtaining the existing MAC address The existing MAC address may be obtained by the following methods: 1. 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`. + find your ethernet device (e.g., **enpXXX** or **ethXXX**), + and look for a set of 12 colon-delimited + [hexadecimal digits](https://en.wikipedia.org/wiki/Hexadecimal). + For example: `00:f3:f0:45:91:fe`. * `$ ip link` -- cgit v1.2.3-70-g09d2