As DeNIC wants to have other values, then what is default and
not changeable in /lib/ndb/local, was this patch created. Now
you can change the SOA values of "retry" and "expire", where
the last one is expected to be higher than 604800, when host-
ing a .de domain - in contrast to the 86400 (Day) default.

Reference: /n/sources/patch/applied/dns-soa-expire
Date: Tue Aug  9 17:09:25 CES 2005

--- /sys/src/cmd/ndb/dblookup.c	Tue Aug  9 17:09:12 2005
+++ /sys/src/cmd/ndb/dblookup.c	Tue Aug  9 17:09:06 2005
@@ -416,6 +416,12 @@
 	rp->soa->retry = Hour;
 	rp->soa->expire = Day;
 	rp->soa->minttl = Day;
+	t = look(entry, pair, "retry");
+	if(t)
+		rp->soa->retry = atoi(t->val);
+	t = look(entry, pair, "expire");
+	if(t)
+		rp->soa->expire = atoi(t->val);
 	t = look(entry, pair, "ttl");
 	if(t)
 		rp->soa->minttl = atoi(t->val);