Follow up from T184209
Looking at codfw (but it's similar in eqiad)
We currently use the following IPv6 for the
labs cloud ranges:
ae2.2122 - labs-support1-b-codfw - 2620:0:860:122::/64
ae2.2118 - labs-hosts1-b-codfw - 2620:0:860:118::/64
ae2.2120 - labs-instance-transport1-b-codfw - 2620:0:860:120::/64
The reason was probably including part of the vlan ID in the IP.
But this falls into the larger subnet 2620:0:860:100::/56 - codfw private
It's not an issue right now, especially as cloud doesn't use much IPv6, but might be an issue in the future.
I see 2 options:
1/ use a different /56
2620:0:860:200::/56 - labs-codfw 2620:0:861:200::/56 - labs-eqiad
2/ use dedicated /48s
2a02:ec80:0::/44 - labs (16 * /48) (can be shrinked to a /45) 2a02:ec80:0::/48 - labs eqiad XXXX 2a02:ec80:1::/48 - labs codfw 2a02:ec80:1:2122::/64 - 2122 - labs-support1-b-codfw (84A) 2a02:ec80:1:2118::/64 - 2118 - labs-hosts1-b-codfw (846) 2a02:ec80:1:2120::/64 - 2120 - labs-instance-transport1-b-codfw (848)
Having the vlanID in decimal in the IP makes it easier to understand, but we can also use the hex value (2122->84A) so it's more accurate.
1/ is more of a short term solution while 2/ will require more work (advertise new /48s to the world) but is the most sustainable option.