diff --git a/contrib/seeds/makeseeds.py b/contrib/seeds/makeseeds.py
index 386dc94fce..79a243ba52 100755
--- a/contrib/seeds/makeseeds.py
+++ b/contrib/seeds/makeseeds.py
@@ -91,14 +91,23 @@ def filtermultipayoutaddress(mns):
     return [mn for mn in mns if len(hist[mn['state']['payoutAddress']]) == 1]
 
 def resolveasn(resolver, ip):
-    asn = int([x.to_text() for x in resolver.resolve('.'.join(reversed(ip.split('.'))) + '.origin.asn.cymru.com', 'TXT').response.answer][0].split('\"')[1].split(' ')[0])
+    if ip['net'] == 'ipv4':
+        ipaddr = ip['ip']
+        prefix = '.origin'
+    else:                  # http://www.team-cymru.com/IP-ASN-mapping.html
+        res = str()                         # 2001:4860:b002:23::68
+        for nb in ip['ip'].split(':')[:4]:  # pick the first 4 nibbles
+            for c in nb.zfill(4):           # right padded with '0'
+                res += c + '.'              # 2001 4860 b002 0023
+        ipaddr = res.rstrip('.')            # 2.0.0.1.4.8.6.0.b.0.0.2.0.0.2.3
+        prefix = '.origin6'
+    asn = int([x.to_text() for x in resolver.resolve('.'.join(reversed(ipaddr.split('.'))) + prefix  + '.asn.cymru.com', 'TXT').response.answer][0].split('\"')[1].split(' ')[0])
     return asn
 
 # Based on Greg Maxwell's seed_filter.py
 def filterbyasn(ips, max_per_asn, max_total):
     # Sift out ips by type
-    ips_ipv4 = [ip for ip in ips if ip['net'] == 'ipv4']
-    ips_ipv6 = [ip for ip in ips if ip['net'] == 'ipv6']
+    ips_ipv46 = [ip for ip in ips if ip['net'] in ['ipv4', 'ipv6']]
     ips_onion = [ip for ip in ips if ip['net'] == 'onion']
 
     my_resolver = dns.resolver.Resolver()
@@ -109,13 +118,12 @@ def filterbyasn(ips, max_per_asn, max_total):
     my_resolver.nameservers = ['208.67.222.222', '208.67.220.220']
 
     # Resolve ASNs in parallel
-    asns = [pool.apply_async(resolveasn, args=(my_resolver, ip['ip'])) for ip in ips_ipv4]
+    asns = [pool.apply_async(resolveasn, args=(my_resolver, ip)) for ip in ips_ipv46]
 
-    # Filter IPv4 by ASN
+    # Filter IPv46 by ASN
     result = []
     asn_count = {}
-    for i in range(len(ips_ipv4)):
-        ip = ips_ipv4[i]
+    for i, ip in enumerate(ips_ipv46):
         if len(result) == max_total:
             break
         try:
@@ -129,10 +137,7 @@ def filterbyasn(ips, max_per_asn, max_total):
         except:
             sys.stderr.write('ERR: Could not resolve ASN for "' + ip['ip'] + '"\n')
 
-    # TODO: filter IPv6 by ASN
-
-    # Add back non-IPv4
-    result.extend(ips_ipv6)
+    # Add back Onions
     result.extend(ips_onion)
     return result