Network connectivity Ubuntu 12.04
Hi, I am running Ubuntu 12.04 on a Dell Optiplex 780. It used to work fine network connectivity no problems with previous versions of Ubuntu but now accessing the web is almost impossible in the last hour I have had to drop and reestablish the connection to the network about 15 times. In fact just about every time I click on a link Firefox just sits there churning away trying to connect and getting nowhere for as long as I care to leave it trying. I have a wired connection via a University LAN. If I disconnect then reconnect then reload the page it is there almost instantly. It doesn't appear to be a Firefox problem as I get similar with aptitude from the comment line and Chromium. It doesn't seem to be a network problem as other computers plugged into the network connect and remain stable. The only weirdness that seems to be from the network is the proxies sometimes it ONLY works with auto detect sometimes it only works with manual and this can vary several times throughout the day. My best guess is something screwy in Ubuntu or a network cable going bad. I have a new cable on order to eliminate that any ideas what else it could be? Stripes.
On 9 January 2013 16:02, stripes theotoky <stripes.theotoky@googlemail.com>wrote:
I am running Ubuntu 12.04 on a Dell Optiplex 780. It used to work fine network connectivity no problems with previous versions of Ubuntu but now accessing the web is almost impossible in the last hour I have had to drop and reestablish the connection to the network about 15 times. In fact just about every time I click on a link Firefox just sits there churning away trying to connect and getting nowhere for as long as I care to leave it trying.
Can you please describe in more detail what do you do to re-establish the network connection? Thanks -- Brian May <brian@microcomaustralia.com.au>
On 09/01/13 16:02, stripes theotoky wrote:
I have a wired connection via a University LAN. If I disconnect then reconnect then reload the page it is there almost instantly.
Is there anything odd appearing in dmesg? When it's not working what does this command say? host google.com That'll say whether DNS is affected (or not). Can you install tcptraceroute and then when your connection is not working can you also try: sudo tcptraceroute -n 74.125.237.142 to see what's going on with a TCP connection to Google? cheers, Chris -- Chris Samuel : http://www.csamuel.org/ : Melbourne, VIC
Just got back to work to find the network frozen again so ran the following tests host seems as if DNS is working and I can't run tcptraceroute because right now the network is behaving but have installed it and will run it the next time the network freezes. Stripes Is there anything odd appearing in dmesg?
dmesg looks weird to me but I don't know enough to know what it is trying to tell me. [96377.098569] [UFW BLOCK] IN=eth0 OUT= MAC=84:2b:2b:b4:ee:09:00:17:0f:ed:ee:c0:08:00 SRC=131.172.8.83 DST=131.172.182.35 LEN=60 TOS=0x00 PREC=0x00 TTL=125 ID=1726 DF PROTO=TCP SPT=10002 DPT=38193 WINDOW=8192 RES=0x00 ACK SYN URGP=0 [96397.271477] [UFW BLOCK] IN=eth0 OUT= MAC=84:2b:2b:b4:ee:09:00:17:0f:ed:ee:c0:08:00 SRC=131.172.8.83 DST=131.172.182.35 LEN=60 TOS=0x00 PREC=0x00 TTL=125 ID=1878 DF PROTO=TCP SPT=10002 DPT=58486 WINDOW=8192 RES=0x00 ACK SYN URGP=0 [96417.093354] [UFW BLOCK] IN=eth0 OUT= MAC=84:2b:2b:b4:ee:09:00:17:0f:ed:ee:c0:08:00 SRC=131.172.8.83 DST=131.172.182.35 LEN=60 TOS=0x00 PREC=0x00 TTL=125 ID=2022 DF PROTO=TCP SPT=10002 DPT=40273 WINDOW=8192 RES=0x00 ACK SYN URGP=0 [96436.994151] [UFW BLOCK] IN=eth0 OUT= MAC=84:2b:2b:b4:ee:09:00:17:0f:ed:ee:c0:08:00 SRC=131.172.8.83 DST=131.172.182.35 LEN=40 TOS=0x00 PREC=0x00 TTL=125 ID=2170 DF PROTO=TCP SPT=10002 DPT=52514 WINDOW=0 RES=0x00 RST URGP=0 [96457.439909] [UFW BLOCK] IN=eth0 OUT= MAC=84:2b:2b:b4:ee:09:00:17:0f:ed:ee:c0:08:00 SRC=131.172.8.83 DST=131.172.182.35 LEN=60 TOS=0x00 PREC=0x00 TTL=125 ID=2338 DF PROTO=TCP SPT=10002 DPT=49735 WINDOW=8192 RES=0x00 ACK SYN URGP=0 [96477.278106] [UFW BLOCK] IN=eth0 OUT= MAC=84:2b:2b:b4:ee:09:00:17:0f:ed:ee:c0:08:00 SRC=131.172.8.83 DST=131.172.182.35 LEN=60 TOS=0x00 PREC=0x00 TTL=125 ID=2492 DF PROTO=TCP SPT=10002 DPT=39062 WINDOW=8192 RES=0x00 ACK SYN URGP=0 [96497.097806] [UFW BLOCK] IN=eth0 OUT= MAC=84:2b:2b:b4:ee:09:00:17:0f:ed:ee:c0:08:00 SRC=131.172.8.83 DST=131.172.182.35 LEN=60 TOS=0x00 PREC=0x00 TTL=125 ID=2642 DF PROTO=TCP SPT=10002 DPT=63464 WINDOW=8192 RES=0x00 ACK SYN URGP=0 [96517.264219] [UFW BLOCK] IN=eth0 OUT= MAC=84:2b:2b:b4:ee:09:00:17:0f:ed:ee:c0:08:00 SRC=131.172.8.83 DST=131.172.182.35 LEN=60 TOS=0x00 PREC=0x00 TTL=125 ID=2801 DF PROTO=TCP SPT=10002 DPT=41087 WINDOW=8192 RES=0x00 ACK SYN URGP=0 [96537.157160] [UFW BLOCK] IN=eth0 OUT= MAC=84:2b:2b:b4:ee:09:00:17:0f:ed:ee:c0:08:00 SRC=131.172.8.83 DST=131.172.182.35 LEN=40 TOS=0x00 PREC=0x00 TTL=125 ID=2981 DF PROTO=TCP SPT=10002 DPT=58972 WINDOW=0 RES=0x00 RST URGP=0 [96557.000166] [UFW BLOCK] IN=eth0 OUT= MAC=84:2b:2b:b4:ee:09:00:17:0f:ed:ee:c0:08:00 SRC=131.172.8.83 DST=131.172.182.35 LEN=60 TOS=0x00 PREC=0x00 TTL=125 ID=3124 DF PROTO=TCP SPT=10002 DPT=51388 WINDOW=8192 RES=0x00 ACK SYN URGP=0 [96577.021152] [UFW BLOCK] IN=eth0 OUT= MAC=84:2b:2b:b4:ee:09:00:17:0f:ed:ee:c0:08:00 SRC=131.172.8.83 DST=131.172.182.35 LEN=56 TOS=0x00 PREC=0x00 TTL=125 ID=3283 DF PROTO=TCP SPT=10002 DPT=34476 WINDOW=65535 RES=0x00 ACK SYN URGP=0 [96597.425777] [UFW BLOCK] IN=eth0 OUT= MAC=84:2b:2b:b4:ee:09:00:17:0f:ed:ee:c0:08:00 SRC=131.172.8.83 DST=131.172.182.35 LEN=60 TOS=0x00 PREC=0x00 TTL=125 ID=3437 DF PROTO=TCP SPT=10002 DPT=38699 WINDOW=8192 RES=0x00 ACK SYN URGP=0 [96617.245539] [UFW BLOCK] IN=eth0 OUT= MAC=84:2b:2b:b4:ee:09:00:17:0f:ed:ee:c0:08:00 SRC=131.172.8.83 DST=131.172.182.35 LEN=60 TOS=0x00 PREC=0x00 TTL=125 ID=3582 DF PROTO=TCP SPT=10002 DPT=40359 WINDOW=8192 RES=0x00 ACK SYN URGP=0 [96637.036939] [UFW BLOCK] IN=eth0 OUT= MAC=84:2b:2b:b4:ee:09:00:17:0f:ed:ee:c0:08:00 SRC=131.172.8.83 DST=131.172.182.35 LEN=60 TOS=0x00 PREC=0x00 TTL=125 ID=3732 DF PROTO=TCP SPT=10002 DPT=54144 WINDOW=8192 RES=0x00 ACK SYN URGP=0 [96657.206130] [UFW BLOCK] IN=eth0 OUT= MAC=84:2b:2b:b4:ee:09:00:17:0f:ed:ee:c0:08:00 SRC=131.172.8.83 DST=131.172.182.35 LEN=60 TOS=0x00 PREC=0x00 TTL=125 ID=3884 DF PROTO=TCP SPT=10002 DPT=37665 WINDOW=8192 RES=0x00 ACK SYN URGP=0 [97797.065193] [UFW BLOCK] IN=eth0 OUT= MAC=84:2b:2b:b4:ee:09:00:17:df:5b:b6:40:08:00 SRC=69.175.126.170 DST=131.172.182.35 LEN=74 TOS=0x00 PREC=0x00 TTL=46 ID=0 DF PROTO=UDP SPT=40369 DPT=5353 LEN=54 [102387.437169] [UFW BLOCK] IN=eth0 OUT= MAC=84:2b:2b:b4:ee:09:00:17:df:5b:b6:40:08:00 SRC=213.131.66.37 DST=131.172.182.35 LEN=44 TOS=0x00 PREC=0x00 TTL=41 ID=0 DF PROTO=ICMP TYPE=8 CODE=0 ID=4396 SEQ=256 [107008.373813] [UFW BLOCK] IN=eth0 OUT= MAC=84:2b:2b:b4:ee:09:00:17:df:5b:b6:40:08:00 SRC=10.11.250.1 DST=131.172.182.35 LEN=61 TOS=0x00 PREC=0x00 TTL=125 ID=19923 PROTO=ICMP TYPE=8 CODE=0 ID=289 SEQ=18360 [107228.020982] [UFW BLOCK] IN=eth0 OUT= MAC=84:2b:2b:b4:ee:09:00:17:df:5b:b6:40:08:00 SRC=101.44.1.135 DST=131.172.182.35 LEN=48 TOS=0x00 PREC=0x00 TTL=103 ID=38101 PROTO=TCP SPT=276 DPT=22 WINDOW=65535 RES=0x00 SYN URGP=0
When it's not working what does this command say?
host google.com
host seems as if DNS is working host google.com google.com has address 74.125.237.6 google.com has address 74.125.237.7 google.com has address 74.125.237.8 google.com has address 74.125.237.9 google.com has address 74.125.237.14 google.com has address 74.125.237.0 google.com has address 74.125.237.1 google.com has address 74.125.237.2 google.com has address 74.125.237.3 google.com has address 74.125.237.4 google.com has address 74.125.237.5 google.com has IPv6 address 2404:6800:4006:800::1005 google.com mail is handled by 10 aspmx.l.google.com. google.com mail is handled by 20 alt1.aspmx.l.google.com. google.com mail is handled by 30 alt2.aspmx.l.google.com. google.com mail is handled by 40 alt3.aspmx.l.google.com. google.com mail is handled by 50 alt4.aspmx.l.google.com. That'll say whether DNS is affected (or not).
Can you install tcptraceroute and then when your connection is not
working can you also try:
sudo tcptraceroute -n 74.125.237.142
sudo tcptraceroute -n 74.125.237.142 Selected device eth0, address 131.172.182.35, port 43046 for outgoing packets Tracing the path to 74.125.237.142 on TCP port 80 (http), 30 hops max 1 131.172.182.251 0.267 ms 0.215 ms 0.216 ms 2 * * * 3 * * * 4 * * * 5 * * * 6 * * * 7 * * * 8 * * * 9 * * * 10 * * * 11 * * * 12 * * * 13 * * * 14 * * * 15 * * * 16 * * * 17 * * * 18 * * * 19 * * * 20 * * * 21 * * * 22 * * * 23 * * * 24 * * * 25 * * * 26 * * * 27 * * * 28 * * * 29 * * * 30 * * * Destination not reached
to see what's going on with a TCP connection to Google?
Thanks Stripes
cheers, Chris -- Chris Samuel : http://www.csamuel.org/ : Melbourne, VIC _______________________________________________ luv-main mailing list luv-main@luv.asn.au http://lists.luv.asn.au/listinfo/luv-main
participants (3)
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Brian May -
Chris Samuel -
stripes theotoky