0

I have a fresh install of 14.04. I am unable to browse any website using both Ubuntu browser and Firefox (the only browsers installed by default). However, when I drop the terminal I am able to ping all websites and I get a successful connection using telnet. Other computers on the network are able to browse without a problem.

I am experiencing very similar issues to Connection times out in all browsers, but ping and telnet work except I am unable to browse to my router web interface as well, unlike the previous poster.

I did a tcpdump although I'm not really sure what I'm looking for. I do see that my computer (10.0.0.23) is requesting the A record from the DNS server and is receiving it then trying to connect to the server, but past that I'm not sure what I'm looking at:

11:38:25.938342 IP 10.0.0.23.32925 > 75.75.75.75.53: 15275+ A? www.google.com. (32)
11:38:25.938416 IP 10.0.0.23.32925 > 75.75.76.76.53: 15275+ A? www.google.com. (32)
11:38:25.975842 IP 75.75.75.75.53 > 10.0.0.23.32925: 15275 6/0/0 A 64.233.176.105, A 64.233.176.103, A 64.233.176.106, A 64.233.176.147, A 64.233.176.104, A 64.233.176.99 (128)
11:38:25.976955 IP 10.0.0.23.57541 > 64.233.176.105.80: Flags [S], seq 2691308772, win 29200, options [mss 1460,sackOK,TS val 91559 ecr 0,nop,wscale 7], length 0
11:38:25.998335 IP 75.75.76.76.53 > 10.0.0.23.32925: 15275 5/0/0 A 173.194.37.51, A 173.194.37.52, A 173.194.37.48, A 173.194.37.50, A 173.194.37.49 (112)
11:38:25.998411 IP 10.0.0.23 > 75.75.76.76: ICMP 10.0.0.23 udp port 32925 unreachable, length 148
11:38:26.028372 IP 64.233.176.105.80 > 10.0.0.23.57541: Flags [S.], seq 4291033804, ack 2691308773, win 42540, options [mss 1430,sackOK,TS val 2140513279 ecr 91559,nop,wscale 7], length 0
11:38:26.028456 IP 10.0.0.23.57541 > 64.233.176.105.80: Flags [.], ack 1, win 229, options [nop,nop,TS val 91572 ecr 2140513279], length 0
11:38:26.028815 IP 10.0.0.23.57541 > 64.233.176.105.80: Flags [P.], seq 1:291, ack 1, win 229, options [nop,nop,TS val 91572 ecr 2140513279], length 290
11:38:26.056790 IP 64.233.176.105.80 > 10.0.0.23.57541: Flags [.], ack 291, win 341, options [nop,nop,TS val 2140513334 ecr 91572], length 0
11:38:30.995159 IP6 fe80::5e57:1aff:fed3:ee91 > ff02::1: ICMP6, router advertisement, length 104
11:38:32.966693 IP 10.0.0.1 > 224.0.0.1: igmp query v3 [max resp time 1.0s]
11:38:33.085665 IP 10.0.0.23 > 224.0.0.22: igmp v3 report, 1 group record(s)
11:38:33.108831 IP 10.0.0.15 > 224.0.0.22: igmp v3 report, 3 group record(s)
11:38:33.132271 IP 10.0.0.10 > 224.0.0.22: igmp v3 report, 3 group record(s)
11:38:33.296856 IP 169.254.237.81 > 224.0.0.22: igmp v3 report, 3 group record(s)
11:38:33.337661 IP 10.0.0.23.45440 > 74.125.137.136.443: Flags [.], ack 1, win 229, options [nop,nop,TS val 93400 ecr 2013263489,nop,nop,sack 1 {3928:3929}], length 0
11:38:33.357832 IP 74.125.137.136.443 > 10.0.0.23.45440: Flags [R], seq 1761464578, win 0, length 0
11:38:33.359058 IP 10.0.0.23.34167 > 216.58.216.64.443: Flags [S], seq 2488380, win 29200, options [mss 1460,sackOK,TS val 93405 ecr 0,nop,wscale 7], length 0
11:38:33.402075 IP 216.58.216.64.443 > 10.0.0.23.34167: Flags [S.], seq 3539282909, ack 2488381, win 42540, options [mss 1430,sackOK,TS val 2608512891 ecr 93405,nop,wscale 7], length 0
11:38:33.402158 IP 10.0.0.23.34167 > 216.58.216.64.443: Flags [.], ack 1, win 229, options [nop,nop,TS val 93416 ecr 2608512891], length 0
11:38:33.402789 IP 10.0.0.23.34167 > 216.58.216.64.443: Flags [P.], seq 1:165, ack 1, win 229, options [nop,nop,TS val 93416 ecr 2608512891], length 164
11:38:33.443965 IP 216.58.216.64.443 > 10.0.0.23.34167: Flags [.], ack 165, win 341, options [nop,nop,TS val 2608512935 ecr 93416], length 0
11:38:34.003661 IP6 fe80::5e57:1aff:fed3:ee91 > ff02::1: ICMP6, router advertisement, length 104
11:38:34.297675 IP 10.0.0.23.41148 > 91.189.90.40.80: Flags [F.], seq 0, ack 1, win 229, options [nop,nop,TS val 93640 ecr 2356877716,nop,nop,sack 1 {2459:2460}], length 0
11:38:36.057656 IP 10.0.0.23.57541 > 64.233.176.105.80: Flags [.], ack 1, win 229, options [nop,nop,TS val 94080 ecr 2140513334], length 0
11:38:36.995166 IP6 fe80::5e57:1aff:fed3:ee91 > ff02::1: ICMP6, router advertisement, length 104
11:38:37.057655 IP 10.0.0.23.57541 > 64.233.176.105.80: Flags [.], ack 1, win 229, options [nop,nop,TS val 94330 ecr 2140513334], length 0
11:38:37.083973 IP 64.233.176.105.80 > 10.0.0.23.57541: Flags [.], ack 291, win 341, options [nop,nop,TS val 2140524366 ecr 91572], length 0
11:38:38.342793 IP 10.0.0.15.58164 > 10.0.0.255.32414: UDP, length 21
11:38:39.996784 IP6 fe80::5e57:1aff:fed3:ee91 > ff02::1: ICMP6, router advertisement, length 104
11:38:42.996470 IP6 fe80::5e57:1aff:fed3:ee91 > ff02::1: ICMP6, router advertisement, length 104
11:38:43.344242 IP 10.0.0.15.58164 > 10.0.0.255.32414: UDP, length 21
11:38:43.441646 IP 10.0.0.23.34167 > 216.58.216.64.443: Flags [.], ack 1, win 229, options [nop,nop,TS val 95926 ecr 2608512935], length 0
11:38:43.455840 IP 216.58.216.64.443 > 10.0.0.23.34167: Flags [F.], seq 3927, ack 165, win 341, options [nop,nop,TS val 2608522948 ecr 93416], length 0
11:38:43.455896 IP 10.0.0.23.34167 > 216.58.216.64.443: Flags [.], ack 1, win 229, options [nop,nop,TS val 95929 ecr 2608512935,nop,nop,sack 1 {3927:3928}], length 0
11:38:43.476817 IP 216.58.216.64.443 > 10.0.0.23.34167: Flags [.], ack 165, win 341, options [nop,nop,TS val 2608522968 ecr 93416], length 0
11:38:46.000627 IP6 fe80::5e57:1aff:fed3:ee91 > ff02::1: ICMP6, router advertisement, length 104
11:38:47.097652 IP 10.0.0.23.57541 > 64.233.176.105.80: Flags [.], ack 1, win 229, options [nop,nop,TS val 96840 ecr 2140513334], length 0
11:38:47.117175 IP 64.233.176.105.80 > 10.0.0.23.57541: Flags [.], ack 291, win 341, options [nop,nop,TS val 2140534396 ecr 91572], length 0
11:38:48.349341 IP 10.0.0.15.58164 > 10.0.0.255.32414: UDP, length 21

Output from ping commands:

jtsmith2@SmallServer:~$ ping -c 5 google.com
PING google.com (74.125.196.138) 56(84) bytes of data.
64 bytes from yk-in-f139.1e100.net (74.125.196.139): icmp_seq=1 ttl=44 time=26.5 ms
64 bytes from yk-in-f139.1e100.net (74.125.196.139): icmp_seq=2 ttl=44 time=23.5 ms
64 bytes from yk-in-f139.1e100.net (74.125.196.139): icmp_seq=3 ttl=44 time=18.4 ms
64 bytes from yk-in-f139.1e100.net (74.125.196.139): icmp_seq=4 ttl=44 time=17.1 ms
64 bytes from yk-in-f139.1e100.net (74.125.196.139): icmp_seq=5 ttl=44 time=20.0 ms

--- google.com ping statistics ---
5 packets transmitted, 5 received, 0% packet loss, time 4006ms
rtt min/avg/max/mdev = 17.160/21.144/26.523/3.434 ms

and

jtsmith2@SmallServer:~$ ping -c 5 8.8.8.8
PING 8.8.8.8 (8.8.8.8) 56(84) bytes of data.
64 bytes from 8.8.8.8: icmp_seq=1 ttl=57 time=24.8 ms
64 bytes from 8.8.8.8: icmp_seq=2 ttl=57 time=20.8 ms
64 bytes from 8.8.8.8: icmp_seq=3 ttl=57 time=19.5 ms
64 bytes from 8.8.8.8: icmp_seq=4 ttl=57 time=18.1 ms
64 bytes from 8.8.8.8: icmp_seq=5 ttl=57 time=16.3 ms

--- 8.8.8.8 ping statistics ---
5 packets transmitted, 5 received, 0% packet loss, time 4007ms
rtt min/avg/max/mdev = 16.360/19.942/24.802/2.859 ms

Edit:

I am also unable to use http through wget:

jtsmith2@SmallServer:~$ wget -v www.google.com/robots.txt
--2015-01-09 12:45:42-- http://www.google.com/robots.txt
Resolving www.google.com (www.google.com)... 64.233.185.147, 64.233.185.99, 64.233.185.103, ...
Connectiong to www.google.com (www.google.com)|64.233.185.147|:80... connected.
HTTP request sent, awaiting response...

and it just hangs there.

Edit #2 with more diagnostic info:

jtsmith2@SmallServer:~$ sudo traceroute -n -T -p 80 www.google.com
sudo: traceroute: command not found

jtsmith2@SmallServer:~$ ip route
default via 10.0.0.1 dev wlan0 proto static
10.0.0.0/24 dev wlan0 proto kernel scope link src 10.0.0.23 metric 9

jtsmith2@SmallServer:~$ ip route get 8.8.8.8
8.8.8.8 via 10.0.0.1 dev wlan0 src 10.0.0.23
    cache

jtsmith2@SmallServer:~$ ifconfig wlan0
wlan0     Link encap:Ethernet  HWaddr e0:91:53:1a:c2:92
          inet addr:10.0.0.23  Bcast:10.0.0.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  METRIC:1
          RX packets:4758 errors:0 dropped:0 overruns:0 frame:0
          TX packets:770 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:600533 (600.5 KB)  TX bytes:87112 (87.1 KB)

jtsmith2@SmallServer:~$ sudo ping -c3 -Mdo -n -s1472 www.google.com
PING www.google.com (173.194.37.83) 1472(1500) bytes of data.

--- www.google.com ping statistics ---
3 packets transmitted, 0 received, 100% packet loss, time 2015ms

however about 10 seconds later...

jtsmith2@SmallServer:~$ sudo ping -c3 -Mdo -n -s1472 www.google.com
PING www.google.com (64.233.185.103) 1472(1500) bytes of data.
72 bytes from 64.233.185.103: icmp_seq=1 ttl=44 (truncated)
72 bytes from 64.233.185.103: icmp_seq=2 ttl=44 (truncated)
72 bytes from 64.233.185.103: icmp_seq=3 ttl=44 (truncated)

--- www.google.com ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2003ms
rtt min/avg/max/mdev = 39.738/50.665/72.381/15.357 ms

bumping up one byte though:

jtsmith2@SmallServer:~$ sudo ping -c3 -Mdo -n -s1473 www.google.com
PING www.google.com (74.125.196.105) 1473(1501) bytes of data.
ping: local error: Message too long, mtu=1500
ping: local error: Message too long, mtu=1500
ping: local error: Message too long, mtu=1500

--- www.google.com ping statistics ---
3 packets transmitted, 0 received, 3+ errors, 100% packet loss, time 1999ms

Any ideas or solutions would be very helpful and appreciated.

Improve this question
2
  • Just to verify... Can you post the output of ping -c 5 google.com and ping -c 5 8.8.8.8?
    – Mitch
    Jan 9, 2015 at 17:21
  • @Mitch Just updated with ping info. No lost packets and name seems to be resolving without issue.
    – jtsmith2
    Jan 9, 2015 at 17:43

1 Answer 1

Reset to default
0

Please post output of the following commands and I'll try to help. It's easier to modify my answer here instead of in the comments.

Check the path to www.google.com using TCP traceroute to port 80:

sudo traceroute -n -T -p 80 www.google.com

The configuration of routing:

ip route

The interface used to send packets to external networks:

ip route get 8.8.8.8

Show the configuration of the interface you saw in the output of the command above with:

ifconfig <interface>

I'm particularly interested in the information on what kind of Internet access technology you're using.

Sometimes when you're using access methods such as ADSL, VDSL, etc. the protocol encapsulation overhead can mean that the default MTU of 1500 bytes will allow small responses (such as ICMP packets or simple telnet requests) to come back to your machine but larger responses will be silently dropped because the size of the response + the size of encapsulation protocol headers of multiple layers will exceed your MTU.

If you understand the concept of MTU and want to experiment to find out at what MTU your connectivity starts breaking, you can use ping as a diagnostic tool and request that no fragmentation is done and packets of certain size are sent. Example:

sudo ping -c3 -Mdo -n -s1472 www.google.com

The above will attempt to send out packets with 1472 bytes of ICMP payload + 28 bytes of headers (1500bytes in total) which is likely to fail. Try lowering the size of a payload by adjusting the -s parameter until you start getting replies and let me know what it is.

Please update your question and I'll try to help you figure it out.

UPDATE:

Could you try the command below and see if browsing starts working afterwards?

sudo iptables -t mangle -A POSTROUTING -p tcp --tcp-flags SYN,RST SYN -o wlan0 -j TCPMSS --set-mss 1460
Improve this answer
2
  • Thanks! I've updated the original post with the information. Looks like I don't have traceroute installed though (and can't until I get the network going)
    – jtsmith2
    Jan 9, 2015 at 18:52
  • I've updated my answer (last 3 lines). Give it a go, I'll see how you get on in the morning. Good luck.
    – Marcin Kaminski
    Jan 9, 2015 at 21:47

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .