最近は使えるのかな，とひさびさにエミュレータ..．
はい，DNSエラー．
エミュレータ内にて．
generic_x86:/ $ ifconfig
lo Link encap:UNSPEC
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope: Host
UP LOOPBACK RUNNING MTU:65536 Metric:1
RX packets:6 errors:0 dropped:0 overruns:0 frame:0
TX packets:6 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:310 TX bytes:310
eth0 Link encap:UNSPEC Driver virtio_net
inet addr:10.0.2.15 Bcast:10.0.2.255 Mask:255.255.255.0
inet6 addr: fe80::5054:ff:fe12:3456/64 Scope: Link
inet6 addr: fec0::5054:ff:fe12:3456/64 Scope: Site
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:3506 errors:0 dropped:0 overruns:0 frame:0
TX packets:3523 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:270699 TX bytes:274244
generic_x86:/ $ getprop
...
[net.bt.name]: [Android]
[net.eth0.dns1]: [10.0.2.3]
[net.eth0.gw]: [10.0.2.2]
[net.gprs.local-ip]: [10.0.2.15]
[net.qtaguid_enabled]: [1]
[net.tcp.default_init_rwnd]: [60]
...
仮想ネットワークは正しく構築できているようですが．
Set Up Android Emulator Networking | Android Studio
結局これ，パソコン上のDNSに Google Public DNS アドレスを追記で繋がるようになります．
Firewall などはONのままでよいです．
DNSとして設定されたルータのローカルアドレスをうまくエミュレータ側で認識/変換できないのだろうと思われます．
ちなみに，接続成功時のパソコン内にて以下．
~$ cat /var/run/resolv.conf
#
# Mac OS X Notice
#
# This file is not used by the host name and address resolution
# or the DNS query routing mechanisms used by most processes on
# this Mac OS X system.
#
# This file is automatically generated.
#
search flets-east.jp iptvf.jp
nameserver 192.168.0.1
nameserver 8.8.8.8
nameserver 8.8.4.4
~ $ cat /etc/resolv.conf
#
# Mac OS X Notice
#
# This file is not used by the host name and address resolution
# or the DNS query routing mechanisms used by most processes on
# this Mac OS X system.
#
# This file is automatically generated.
#
search flets-east.jp iptvf.jp
nameserver 192.168.0.1
nameserver 8.8.8.8
nameserver 8.8.4.4
Run Apps on the Android Emulator | Android Studio
エミュレータ内にて setprop -> restart network で接続できたとしても毎回いちいち面倒です．
戻ろう、Genymotion に。
→ Genymotion 無料版 を入れる 2018