DNS issue

I can only believe it's some sort of DNS issue that i can't seem to
figure out on my ubuntu linux laptop. it's been happening on and off
over the last month. Here's what i know:

sometimes there are no problems, sometimes surfing sucks.

i have a router controlling a High Speed DSL connection on my network.
*when surfing on my ubuntu laptop, some sites take 30-45 seconds to
completely download (open). some don't open at all and i get a timeout
error.
*when surfing on my iMac or Windows PC surfing is great/fast, never any
problems.

*when i ping yahoo.com or apple.com (for example) from linux, i get
times of 1000 ms at times (vs) the 30-40 ms i get from my windows or Mac
box.
*sometimes the pings on my ubuntu laptop timeout and i get errors like
"host yahoo.com could not be reached" or "ping: unknown host yahoo.com
" and 100% packet loss. i never get this on my Mac or Windows.
*from linux; if i use 'dig' or 'host' on yahoo or apple and ping their
IP addresses directly. the pings work fast and normally. *always*.

oh ya, and connecting to an internet radio station (somafm.com) with
xmms, which uses the IP address of the station, it always works,
*always* playing streaming music, even when i can't surf or ping to the
station when these problems occur.

/etc/resolv.conf:
search bc.hsia.telus.net
nameserver 192.168.2.1
(192.168.2.1 is my router IP address)

i'll provide more info if needed. but does anyone know what could be
causing these problems on my linux laptop. and never on my iMac or
Windows PC. i use mozilla and firefox on all computers. and the
computers are all plugged into the same router with the same settings
for all computers.

cheers.


--
When you say: "I wrote a program that crashed Windows",
people just stare at you blankly and say: "Hey, I got those
with the system -- for free."
- Linus Torvalds -- (remove _eh to email)


johnny bobby bee

> *when i ping yahoo.com or apple.com (for example) from linux, i get
> times of 1000 ms at times (vs) the 30-40 ms i get from my windows or Mac
> box.
Try "ping -n". Doesn't do reverse DNS on the address.

How fast does "host" return? This would help you figure out if DNS
delays are the problem.

Find out what your router is using for its gateway. Try pinging that.

> i'll provide more info if needed. but does anyone know what could be
> causing these problems on my linux laptop. and never on my iMac or
> Windows PC. i use mozilla and firefox on all computers. and the
> computers are all plugged into the same router with the same settings
> for all computers.
Are you sure you don't have a hardware problem? What is the error count
on your interface?

Maybe post diagnostic stuff (route -n; ifconfig) here. I know you think
you have everything right, but sometimes multiple pairs of eyes can help.

Another thing you can do is run "tcpdump -n" in another window while you
run ping (or use ethereal, with DNS resolution off.) This might turn up
something suspicious.


--
My real e-mail address is *aamci* *at* *optonline* *dot* *net*

"johnny bobby bee" <(E-Mail Removed)> wrote in message
news:OH80e.98588$fc4.52614@edtnps89

> I can only believe it's some sort of DNS issue that i can't seem to
> figure out on my ubuntu linux laptop. it's been happening on and off
> over the last month. Here's what i know:

> /etc/resolv.conf:
> search bc.hsia.telus.net
> nameserver 192.168.2.1

Wrong nameserver(s). For telus.net, they should be:

nameserver 198.161.156.1
nameserver 198.161.157.116

On Wed, 23 Mar 2005 07:14:54 +0000, johnny bobby bee wrote:

> I can only believe it's some sort of DNS issue that i can't seem to
> figure out on my ubuntu linux laptop. it's been happening on and off
> over the last month. Here's what i know:
>
> sometimes there are no problems, sometimes surfing sucks.
>
> i have a router controlling a High Speed DSL connection on my network.
> *when surfing on my ubuntu laptop, some sites take 30-45 seconds to
> completely download (open). some don't open at all and i get a timeout
> error.
> *when surfing on my iMac or Windows PC surfing is great/fast, never any
> problems.
>
> *when i ping yahoo.com or apple.com (for example) from linux, i get
> times of 1000 ms at times (vs) the 30-40 ms i get from my windows or Mac
> box.
> *sometimes the pings on my ubuntu laptop timeout and i get errors like
> "host yahoo.com could not be reached" or "ping: unknown host yahoo.com
> " and 100% packet loss. i never get this on my Mac or Windows.
> *from linux; if i use 'dig' or 'host' on yahoo or apple and ping their
> IP addresses directly. the pings work fast and normally. *always*.
>
> oh ya, and connecting to an internet radio station (somafm.com) with
> xmms, which uses the IP address of the station, it always works,
> *always* playing streaming music, even when i can't surf or ping to the
> station when these problems occur.
>
> /etc/resolv.conf:
> search bc.hsia.telus.net
> nameserver 192.168.2.1
> (192.168.2.1 is my router IP address)
>
> i'll provide more info if needed. but does anyone know what could be
> causing these problems on my linux laptop. and never on my iMac or
> Windows PC. i use mozilla and firefox on all computers. and the
> computers are all plugged into the same router with the same settings
> for all computers.
>
> cheers.

I'd look at these things:

1) I would think you should be getting some external nameserver references
in your /etc/resolv.conf

2) after I installed a bank of internet computers at a local library, I
found that it was taking as long as 30-40 seconds to resolv names. The
main issue here seemed to be that IPV6 was 'getting in the way'. I found
several references in the Mandrake newsgroup as well as here about how to
shut down PV6. This reduced the time taken to resolve to about 12 seconds.
At this point I discovered the timeout issue, so I edited
/sbin/dhclient-script to echo the line 'options timeout:1' to the
/etc/resolv.conf file, and the resolution time dropped to around a second.

possibly you could try the nameserver another user suggested, by putting
it in /sbin/dhclient-script or whatever method your distro uses. I believe
I came across this script when I did 'apropos network'.

good luck

ynotssor wrote:
>> /etc/resolv.conf:
>> search bc.hsia.telus.net
>> nameserver 192.168.2.1
>
> Wrong nameserver(s). For telus.net, they should be:
>
> nameserver 198.161.156.1
> nameserver 198.161.157.116

i don't physically write them in /etc/resolv.conf. some script does. my
/etc/resolv.conf file gets blown away any time the
/etc/init.d/networking script runs or dhclient3. if i manually edit it,
i get no surfing, and eventually it gets written over anyway. do you
know where i could add this to an ubuntu (debian) box that wouldn't get
written over.


--
When you say: "I wrote a program that crashed Windows",
people just stare at you blankly and say: "Hey, I got those
with the system -- for free."
- Linus Torvalds -- (remove _eh to email)

Allen McIntosh wrote:
>> *when i ping yahoo.com or apple.com (for example) from linux, i get
>> times of 1000 ms at times (vs) the 30-40 ms i get from my windows or Mac
>> box.
> Try "ping -n". Doesn't do reverse DNS on the address.
>
> How fast does "host" return? This would help you figure out if DNS
> delays are the problem.
>

depends - when the surfing sucks, then host takes a long time. when
surfing is ok, then both host and ping (without n) are ok. it happens
minute by minute. some times pages load great. sometimes not at all.
timeouts, etc.

> Find out what your router is using for its gateway. Try pinging that.

well since they're IP numbers it pings it quickly:
shine@ubuntu-shine:~ $ ping -c3 154.20.128.254
PING 154.20.128.254 (154.20.128.254) 56(84) bytes of data.
64 bytes from 154.20.128.254: icmp_seq=1 ttl=126 time=16.2 ms
64 bytes from 154.20.128.254: icmp_seq=2 ttl=126 time=86.2 ms
64 bytes from 154.20.128.254: icmp_seq=3 ttl=126 time=16.9 ms

> Are you sure you don't have a hardware problem? What is the error count
> on your interface?
>

ifconfig never shows Tx or Rx errors:
eth0 Link encap:Ethernet HWaddr 00:09:5B:83:F4:53
inet addr:192.168.2.103 Bcast:192.168.2.255 Mask:255.255.255.0
inet6 addr: fe80::209:5bff:fe83:f453/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:394844 errors:0 dropped:0 overruns:0 frame:0
TX packets:272816 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:382092282 (364.3 MiB) TX bytes:22539671 (21.4 MiB)
Interrupt:11

> Maybe post diagnostic stuff (route -n; ifconfig) here. I know you think
> you have everything right, but sometimes multiple pairs of eyes can help.
>

shine@ubuntu-shine:~ $ route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use
Iface
192.168.2.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0
0.0.0.0 192.168.2.1 0.0.0.0 UG 0 0 0 eth0

> Another thing you can do is run "tcpdump -n" in another window while you
> run ping (or use ethereal, with DNS resolution off.) This might turn up
> something suspicious.

guess ill try this another time. what should i look for (suspicious)?


--
When you say: "I wrote a program that crashed Windows",
people just stare at you blankly and say: "Hey, I got those
with the system -- for free."
- Linus Torvalds -- (remove _eh to email)