Dtyjlui

I just upgraded from Ubuntu 17 to 18.04 and everything seemed to go pretty smoothly.

However, after the upgrade, there have been two (probably directly related issues). 1, the configuration application for my VPN (mullvad) no longer starts, which is not too pressing of an issue. 2, perhaps caused by some configuration originally managed by the VPN application, all my DNS queries from browsers are super slow.

I have tested from Chrome, Firefox, and Waterfox, and in all cases, it seems that DNS queries take between 5 to 5.2 seconds. I assume there is some incorrect configuration somewhere which is timing out after 5 seconds, then the browser proceeds with another configuration and gets a quick response back.

Here is a typical page load waterfall:

On the other hand, when I go to the command line and try dig, I get a speedy response:

$ dig www.disney.com



; <<>> DiG 9.11.3-1ubuntu1-Ubuntu <<>> www.disney.com

;; global options: +cmd

;; Got answer:

;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 35027

;; flags: qr rd ra; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 1



;; OPT PSEUDOSECTION:

; EDNS: version: 0, flags:; udp: 65494

;; QUESTION SECTION:

;www.disney.com.            IN  A



;; ANSWER SECTION:

www.disney.com.     255 IN  CNAME   matterhornsecure.edgekey.net.

matterhornsecure.edgekey.net. 743 IN    CNAME   e13055.e12.akamaiedge.net.

e13055.e12.akamaiedge.net. 19   IN  A   23.54.221.6



;; Query time: 30 msec

;; SERVER: 127.0.0.53#53(127.0.0.53)

;; WHEN: Mon Jun 04 20:59:26 EDT 2018

;; MSG SIZE  rcvd: 137

I set my DNS server to a Cloudflare DNS server, 1.1.1.1, but I'm not sure how that may be impacting this.

Here is some other information that I have seen asked about on other similar threads:

$ ifconfig

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536

        inet 127.0.0.1  netmask 255.0.0.0

        inet6 ::1  prefixlen 128  scopeid 0x10<host>

        loop  txqueuelen 1000  (Local Loopback)

        RX packets 11020  bytes 915775 (915.7 KB)

        RX errors 0  dropped 0  overruns 0  frame 0

        TX packets 11020  bytes 915775 (915.7 KB)

        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0



tun0: flags=4305<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST>  mtu 1500

        inet 10.11.0.19  netmask 255.255.0.0  destination 10.11.0.19

        inet6 fdda:d0d0:cafe:1197::1011  prefixlen 64  scopeid 0x0<global>

        inet6 fe80::a6e6:1fa2:8d15:cf1  prefixlen 64  scopeid 0x20<link>

        unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00  txqueuelen 100  (UNSPEC)

        RX packets 0  bytes 0 (0.0 B)

        RX errors 0  dropped 0  overruns 0  frame 0

        TX packets 0  bytes 0 (0.0 B)

        TX errors 0  dropped 1000 overruns 0  carrier 0  collisions 0



wlp2s0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500

        inet 192.168.0.7  netmask 255.255.255.0  broadcast 192.168.0.255

        inet6 fe80::9b85:3e1:c0d1:d2f9  prefixlen 64  scopeid 0x20<link>

        inet6 2604:2000:81c2:300::3  prefixlen 128  scopeid 0x0<global>

        inet6 2604:2000:81c2:300:b765:7f68:a70b:8ebd  prefixlen 64  scopeid 0x0<global>

        ether 34:02:86:60:d3:30  txqueuelen 1000  (Ethernet)

        RX packets 41063  bytes 49615001 (49.6 MB)

        RX errors 0  dropped 0  overruns 0  frame 0

        TX packets 13120  bytes 2266057 (2.2 MB)

        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0



$ nmcli device show wlp2s0 | grep IP4.DNS

IP4.DNS[1]:                             1.1.1.1

IP4.DNS[2]:                             1.0.0.1

For me it was a timeout while waiting for an AAAA query (IPv6) to end before responding even though an A record was already resolved.
The solution that worked for me is this.

add these lines to /etc/resolv.conf (the options is the secret sauce).

nameserver 1.1.1.1

nameserver 1.0.0.1

options single-request

on desktop systems it should be added to /etc/resolvconf/resolv.conf.d/base instead because /etc/resolv.conf gets rewritten automatically.
then run these commands:

sudo resolvconf -u

sudo systemctl restart networking

sudo systemctl restart network-manager

solution from http://www.math.tamu.edu/~comech/tools/linux-slow-dns-lookup/

Included a screenshot of my Firefox dns settings that works well for me.

And if you want to try enabling local caching name server.

$ sudo apt-get install bind9 bind9utils bind9-doc

$ sudo vi /etc/bind/named.conf.options

And add the following under the option section.

    forwarders {

            8.8.8.8;

            8.8.4.4;

    };

And restart the bind service.

$ sudo systemctl restart bind9.service

It should do some pretty good caching with the default configurations.

$ dig www.disney.com



; <<>> DiG 9.11.3-1ubuntu1.1-Ubuntu <<>> www.disney.com

;; global options: +cmd

;; Got answer:

;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 2237

;; flags: qr rd ra; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 1



;; OPT PSEUDOSECTION:

; EDNS: version: 0, flags:; udp: 65494

;; QUESTION SECTION:

;www.disney.com.            IN  A



;; ANSWER SECTION:

www.disney.com.     300 IN  CNAME   matterhornsecure.edgekey.net.

matterhornsecure.edgekey.net. 7199 IN   CNAME   e13055.e12.akamaiedge.net.

e13055.e12.akamaiedge.net. 19   IN  A   2.19.151.249



;; Query time: 108 msec

;; SERVER: 127.0.0.53#53(127.0.0.53)

;; WHEN: Mon Jul 09 12:48:28 PDT 2018

;; MSG SIZE  rcvd: 137



$ dig www.disney.com



; <<>> DiG 9.11.3-1ubuntu1.1-Ubuntu <<>> www.disney.com

;; global options: +cmd

;; Got answer:

;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 732

;; flags: qr rd ra; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 1



;; OPT PSEUDOSECTION:

; EDNS: version: 0, flags:; udp: 65494

;; QUESTION SECTION:

;www.disney.com.            IN  A



;; ANSWER SECTION:

www.disney.com.     292 IN  CNAME   matterhornsecure.edgekey.net.

matterhornsecure.edgekey.net. 7192 IN   CNAME   e13055.e12.akamaiedge.net.

e13055.e12.akamaiedge.net. 12   IN  A   2.19.151.249



;; Query time: 0 msec

;; SERVER: 127.0.0.53#53(127.0.0.53)

;; WHEN: Mon Jul 09 12:48:35 PDT 2018

;; MSG SIZE  rcvd: 137

Note that the second query takes no time at all. It also takes no time to do dns query in Firefox for me too.