Merge ~andreserl/maas:lp1718209 into maas:master

[Andres Rodriguez]

LP: #1718209 - Fix IPv6 DHCP PXE configuration.

[Mike Pontillo (mpontillo)]

Looks good. Needs a commit message / bug link though.

review: Approve

[MAAS Lander (maas-lander)]

LANDING
-b lp1718209 lp:~andreserl/maas into -b master lp:~maas-committers/maas

STATUS: FAILED BUILD
LOG: http://maas-ci-jenkins.internal:8080/job/maas/job/branch-tester/351/consoleText

diff --git a/src/provisioningserver/dhcp/config.py b/src/provisioningserver/dhcp/config.py
index 024a17e..160d30d 100644
--- a/src/provisioningserver/dhcp/config.py
+++ b/src/provisioningserver/dhcp/config.py
@@ -47,7 +47,8 @@ logger = logging.getLogger(__name__)
 # Used to generate the conditional bootloader behaviour
 CONDITIONAL_BOOTLOADER = ("""
 {{if ipv6}}
-           {{behaviour}} client-arch-type = {{arch_octet}} {
+           {{behaviour}} exists dhcp6.client-arch-type and
+             option dhcp6.client-arch-type = {{arch_octet}} {
                option dhcp6.bootfile-url \"{{url}}\";
            }
 {{else}}
diff --git a/src/provisioningserver/templates/dhcp/dhcpd6.conf.template b/src/provisioningserver/templates/dhcp/dhcpd6.conf.template
index b1e33f3..e7b2394 100644
--- a/src/provisioningserver/templates/dhcp/dhcpd6.conf.template
+++ b/src/provisioningserver/templates/dhcp/dhcpd6.conf.template
@@ -2,7 +2,7 @@
 # overwrite any changes made there.  Instead, you can modify dhcpd6.conf by
 # using DHCP snippets over the API or through the web interface.
 
-option arch code 93 = unsigned integer 16; # RFC4578
+option dhcp6.client-arch-type code 61 = array of unsigned integer 16; # RFC5970
 option path-prefix code 210 = text; #RFC5071
 
 #