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https://en.wikipedia.org/wiki/Unique_local_address

https://www.rfc-editor.org/rfc/rfc4193#section-3.2.2

http://www.sixxs.net/tools/grh/ula/list/

I have been looking for a local script to generate ULAs; there are many online generators (and a few bad/broken) ones; I wanted a local script.

https://www.vultr.com/tools/mac-converter/

http://ben.akrin.com/?p=1347

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Benoit-Pierre DEMAINE
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  • I don't know of a script to generate the Global ID, but there are instructions in the RFC. See [this question](https://networkengineering.stackexchange.com/q/48488/8499). – Ron Maupin Feb 25 '18 at 16:48

2 Answers2

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This should be run on a physical machine; not on an emulated system or virtual env. Tune the if variable according to needs.

if=eth0
t="$(ntptime | grep "time " | head -n1 | awk '{print $2}')"
EUI_48="$(ip a s dev $if | grep "link/ether" | awk '{print $2}')"
EUI_64="$(ipv6calc --action prefixmac2ipv6 --in prefix+mac --out ipv6addr :: $EUI_48 | sed 's/^:://')"
conq="$(echo "$t $EUI_64" | tr -d ".: ")"
sha1="$(for x in $(echo "$conq" | sed 's/\(..\)/\1 /g') ; do printf "\x${x}" ; done | sha1sum | awk '{print $1}' | tail -c 11 | sed 's/\(..\)/\1 /g')"
ULA="$(echo $sha1 | awk '{print "fd" $1 ":" $2 $3 ":" $4 $5 "::/48"}')"
echo "$t $EUI_48 $EUI_64 $conq=> $ULA"

By the way, ipv6calc is designed to produce the link local address this way:

ipv6calc --action prefixmac2ipv6 --in prefix+mac --out ipv6addr fe80:: $EUI_48

If you don't want to install ipv6calc, here is a function to convert EUI-48 into EUI-64: https://gist.github.com/mej/592da948323fc58455c1

Benoit-Pierre DEMAINE
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There already exists this github repository with a bash script that generates ULA. It is written to run interactively and asks for mac address (and confirm an ntp query).

hlovdal
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