diff --git a/etc/tempest.conf.sample b/etc/tempest.conf.sample
index 29f80bd..dcc3c18 100644
--- a/etc/tempest.conf.sample
+++ b/etc/tempest.conf.sample
@@ -747,10 +747,10 @@
 
 # The cidr block to allocate tenant ipv6 subnets from (string
 # value)
-#tenant_network_v6_cidr=2003::/64
+#tenant_network_v6_cidr=2003::/48
 
 # The mask bits for tenant ipv6 subnets (integer value)
-#tenant_network_v6_mask_bits=96
+#tenant_network_v6_mask_bits=64
 
 # Whether tenant network connectivity should be evaluated
 # directly (boolean value)