dns_conf: add bootstrap-dns option for server.

etc/smartdns/smartdns.conf

@@ -50,7 +50,11 @@
 #    bind [::]:53
 #    bind [::]:53@eth0
 #    bind-tcp [::]:53
-bind [::]:53
+bind [::]:7053
+
+server 192.168.1.1:6053 -bootstrap-dns
+server dns.google 
+server 192.168.1.1:6053
 
 # tcp connection idle timeout
 # tcp-idle-time [second]
@@ -144,7 +148,7 @@ force-qtype-SOA 65
 # log-file: file path of log file.
 # log-size: size of each log file, support k,m,g
 # log-num: number of logs, 0 means disable log
-log-level info
+log-level debug
 
 # log-file /var/log/smartdns/smartdns.log
 # log-size 128k
@@ -181,6 +185,7 @@ log-level info
 #   -group [group]: set server to group, use with nameserver /domain/group.
 #   -exclude-default-group: exclude this server from default group.
 #   -proxy [proxy-name]: use proxy to connect to server.
+#   -bootstrap-dns: set as bootstrap dns server.
 # server 8.8.8.8 -blacklist-ip -check-edns -group g1 -group g2
 # server tls://dns.google:853 
 # server https://dns.google/dns-query
@@ -197,6 +202,7 @@ log-level info
 #   -host-name: TLS sni hostname.
 #   -no-check-certificate: no check certificate.
 #   -proxy [proxy-name]: use proxy to connect to server.
+#   -bootstrap-dns: set as bootstrap dns server.
 # Get SPKI with this command:
 #    echo | openssl s_client -connect '[ip]:853' | openssl x509 -pubkey -noout | openssl pkey -pubin -outform der | openssl dgst -sha256 -binary | openssl enc -base64
 # default port is 853
@@ -211,6 +217,7 @@ log-level info
 #   -http-host: http host.
 #   -no-check-certificate: no check certificate.
 #   -proxy [proxy-name]: use proxy to connect to server.
+#   -bootstrap-dns: set as bootstrap dns server.
 # default port is 443
 # server-https https://cloudflare-dns.com/dns-query