DNS64 not always generate synthetic IPv6 addresses for IPv4-only destinations #438
Description
Hello, thanks for your great software!
I'm using AdGuardHome latest release (v0.107.57 as of now) and as far as I know it uses dnsproxy under the hood, so creating issue here
What I have:
- Setup NAT64 with Jool, prefix is fd02:21:64::/96
- Setup AdGuardHome with DNS64 and added my prefix
- Set DHCP option 108
- Added prefix to PREF64 ND
Description of issue:
so my Android phone now using IPv6-only, but unfortunately some applications does not work. Digging a bit I found that synthetic IPv6 does not generates, I guess it could be related to having some CNAME records in response, but not sure.
Attaching powershell commands I used to test + wireshark pcap
Expected result:
- got synthetic IPv6 for
ru-mum.m.alibaba.comlikefd02:21:64::2ff6:88b9
Actual result:
- got only CNAME for AAAA query and CNAME + IPv4 for A query
Current workaround:
Currently I have to disable DHCP option 108 to get IPv4 address as well
Additional info:
pcap file: AdGuardHome-DNS64.zip
(GitHub does not allow attach pcap directly, so compressed to zip)
PowerShell terminal
┏[ 91395 from miniNB][ 0.434s][admin@kubernetes]
┖[~]
└─Δ Resolve-DnsName ru-mum.m.alibaba.com -Type A
Name Type TTL Section NameHost
---- ---- --- ------- --------
ru-mum.m.alibaba.com CNAME 43 Answer ru-mum.m.alibaba.com.gds.alibabadns.com
ru-mum.m.alibaba.com.gds.aliba CNAME 43 Answer default.ovs.us.wagbridge.ae.alibabacorp.com
badns.com
default.ovs.us.wagbridge.ae.al CNAME 43 Answer default.ovs.us.wagbridge.ae.alibabacorp.com.gds.alibabadns.com
ibabacorp.com
Name : default.ovs.us.wagbridge.ae.alibabacorp.com.gds.alibabadns.com
QueryType : A
TTL : 47
Section : Answer
IP4Address : 47.246.136.185
┏[ 91395 from miniNB][ 0.106s][admin@kubernetes]
┖[~]
└─Δ Resolve-DnsName ru-mum.m.alibaba.com -Type AAAA
Name Type TTL Section NameHost
---- ---- --- ------- --------
ru-mum.m.alibaba.com CNAME 117 Answer ru-mum.m.alibaba.com.gds.alibabadns.com
ru-mum.m.alibaba.com.gds.aliba CNAME 117 Answer default.ovs.us.wagbridge.ae.alibabacorp.com
badns.com
default.ovs.us.wagbridge.ae.al CNAME 117 Answer default.ovs.us.wagbridge.ae.alibabacorp.com.gds.alibabadns.com
ibabacorp.com
Name : gds.alibabadns.com
QueryType : SOA
TTL : 241
Section : Authority
NameAdministrator : none
SerialNumber : 2018122017
TimeToZoneRefresh : 1800
TimeToZoneFailureRetry : 600
TimeToExpiration : 3600
DefaultTTL : 360
┏[ 91395 from miniNB][ 0.054s][admin@kubernetes]
┖[~]
└─Δ Resolve-DnsName default.ovs.us.wagbridge.ae.alibabacorp.com.gds.alibabadns.com -Type A
Name Type TTL Section IPAddress
---- ---- --- ------- ---------
default.ovs.us.wagbridge.ae.alibabacorp.com.gd A 106 Answer 47.246.137.66
s.alibabadns.com
┏[ 91395 from miniNB][ 0.085s][admin@kubernetes]
┖[~]
└─Δ Resolve-DnsName default.ovs.us.wagbridge.ae.alibabacorp.com.gds.alibabadns.com -Type AAAA
Name Type TTL Section IPAddress
---- ---- --- ------- ---------
default.ovs.us.wagbridge.ae.alibabacorp.com.gd AAAA 104 Answer fd02:21:64::2ff6:8942
s.alibabadns.com
┏[ 91395 from miniNB][ 0.062s][admin@kubernetes]
┖[~]
└─Δ Resolve-DnsName github.com -Type A
Name Type TTL Section IPAddress
---- ---- --- ------- ---------
github.com A 23 Answer 140.82.121.4
┏[ 91395 from miniNB][ 0.036s][admin@kubernetes]
┖[~]
└─Δ Resolve-DnsName github.com -Type AAAA
Name Type TTL Section IPAddress
---- ---- --- ------- ---------
github.com AAAA 22 Answer fd02:21:64::8c52:7904