unable to visit some websites - MTU Settings?

English Network/Internet
1

hi,

i need help with my network settings.

i recently installed OpenSuse 11.0.
im unable to visit some sites like
live.com,msn(all microsoft sites)

google(i can get to the login page but after signing in i get a blank page). if i clear all the cookies i’m able to login but cannot open mails, gmail keeps saying “unable to connect”. reloading the page gives me a blank page.

yahoo(i can sign in but nothing after that). same as google “unable to connect”. atleast it responds after some time

i used to have similar problems in MS Windows with microsoft sites. after changing the MTU to 1424 on MS Windows, everything was fine

but in opensuse no matter what MTU i set, im unable to connect to those sites

this is what i get from the terminal


localhost:/home/mickey # ping -s 1424 -M do www.google.com
PING www.l.google.com (209.85.153.104) 1424(1452) bytes of data.
^C
--- www.l.google.com ping statistics ---
4 packets transmitted, 0 received, 100% packet loss, time 2999ms

localhost:/home/mickey # ping -s 1420 -M do www.google.com
PING www.l.google.com (209.85.153.104) 1420(1448) bytes of data.
^C
--- www.l.google.com ping statistics ---
3 packets transmitted, 0 received, 100% packet loss, time 2014ms

localhost:/home/mickey # ping -s 1418 -M do www.google.com
PING www.l.google.com (209.85.153.104) 1418(1446) bytes of data.
^C
--- www.l.google.com ping statistics ---
3 packets transmitted, 0 received, 100% packet loss, time 1999ms

and so on…
kept reducing by two…
till


localhost:/home/mickey # ping -s 1398 -M do www.google.com
PING www.l.google.com (209.85.153.104) 1398(1426) bytes of data.
^C
--- www.l.google.com ping statistics ---
3 packets transmitted, 0 received, 100% packet loss, time 2013ms

localhost:/home/mickey # ping -s 1396 -M do www.google.com
PING www.l.google.com (209.85.153.104) 1396(1424) bytes of data.
64 bytes from im-in-f104.google.com (209.85.153.104): icmp_seq=1 ttl=246 (truncated)
64 bytes from im-in-f104.google.com (209.85.153.104): icmp_seq=3 ttl=246 (truncated)
64 bytes from im-in-f104.google.com (209.85.153.104): icmp_seq=4 ttl=246 (truncated)
^C
--- www.l.google.com ping statistics ---
4 packets transmitted, 3 received, 25% packet loss, time 3008ms
rtt min/avg/max/mdev = 55.340/56.361/57.577/0.923 ms

localhost:/home/mickey # ping -s 1397 -M do www.google.com
PING www.l.google.com (209.85.153.104) 1397(1425) bytes of data.
^C
--- www.l.google.com ping statistics ---
4 packets transmitted, 0 received, 100% packet loss, time 3013ms

localhost:/home/mickey # ping -s 1395 -M do www.google.com
PING www.l.google.com (209.85.153.104) 1395(1423) bytes of data.
64 bytes from im-in-f104.google.com (209.85.153.104): icmp_seq=1 ttl=246 (truncated)
64 bytes from im-in-f104.google.com (209.85.153.104): icmp_seq=2 ttl=246 (truncated)
64 bytes from im-in-f104.google.com (209.85.153.104): icmp_seq=3 ttl=246 (truncated)
64 bytes from im-in-f104.google.com (209.85.153.104): icmp_seq=4 ttl=246 (truncated)
64 bytes from im-in-f104.google.com (209.85.153.104): icmp_seq=5 ttl=246 (truncated)
^C
--- www.l.google.com ping statistics ---
5 packets transmitted, 5 received, 0% packet loss, time 4014ms
rtt min/avg/max/mdev = 56.018/57.728/58.459/0.878 ms

localhost:/home/mickey # ping -s 1396  www.google.com
PING www.l.google.com (209.85.153.104) 1396(1424) bytes of data.
64 bytes from im-in-f104.google.com (209.85.153.104): icmp_seq=1 ttl=246 (truncated)
64 bytes from im-in-f104.google.com (209.85.153.104): icmp_seq=2 ttl=246 (truncated)
^C
--- www.l.google.com ping statistics ---
2 packets transmitted, 2 received, 0% packet loss, time 1000ms
rtt min/avg/max/mdev = 55.928/56.100/56.272/0.172 ms
localhost:/home/mickey #

any help would be greatly appreaciated

Thanks in advance

–Vijay

2

Try this which might help but might not: switch off IPv6 : GoTo Yast → Network Devices → Network Settings → Global → Uncheck/deactivate IPv6.

Needs a reboot after that.

3

I’m not sure why you want want to change the MTU unless you are using jumbo frames, which are not handled well by most network equipment. I’ve had very little success changing MTU for jumbo frames in an attempt to get faster transfers to NAS boxes.

The command

/sbin/ifconfig -a

shows the MTU of the various network adapters. My Ethernet adapter has an MTU of 1500.

Irrespective, the commands

cd /etc
find . -type f -print0 | xargs -0 grep -i mtu

might help you locate where the value might be set.

4

Sounds like a DNS problem to me. Why not try going to http://www.dnsserverlist.org/ and enter one of those.

5

thanks for the reply guys
@BotKeeper & swerdna : haven’t yet tried your suggestions yet. didn’t have the time to do so . hopefully tonight i’ll give it a try if i reach home early and reply how it goes
@msounhein the dns is the same that i use on windows. and it works fine there

im not a regular linux user. still trying it out.
so words like " jumbo frames" and “NAS boxes” are new to me.
like somebody said in another thread, i might be asking some real dumb questions :slight_smile:

6

find . -type f -print0 | xargs -0 grep -i mtu
…
…
the last few lines



./ppp/options:# mtu 1492
./ppp/options.pptp:# We want a sane mtu/mru
./ppp/options.pptp:mtu 1000
./ppp/peers/pppoe:# pppoe has a lower mtu/mru
./ppp/peers/pppoe:mtu 1492
./ppp/peers/pppoe-rp:# pppoe has a lower mtu/mru
./ppp/peers/pppoe-rp:mtu 1492

so i set the mtu to 1492
and then i was not even able to login to this forum
reduced it to 1468. i’m able to login to this forum
but still gmail doesnt work nor does msn

and i’ve disable ipv6 as well

7

nobody around?

8

> nobody around?

i think it is more likely that no one knows how to help you…that is
to say that millions have used openSUSE 11.x and not experienced the
problem that you seem to have…

so, something about your computer hardware, openSUSE install, setup,
local network, router, firewall, modem, ISP, ISP switching equipment
settings, MTU, etc etc etc etc etc is screwed up…

where/how can we begin to trouble shoot that for you?

try this: pop in an openSUSE Live CD, or the live CD from ANY Linux
distribution and see if you can get to those troublesome web
sites…if you can NOT, then move to somewhere else (where things are
normal)…

which reminds me: are you in China or some other country which
routinely blocks network traffic??

–
primary

9

Please:
(a) Describe how you connect to the internet
(b) Where and how are you changing the MTU

10

yast->network settings (or something like that)

there i’ve left most of the things as it was except giving inputs like my ip address,subnet mask,default gateway…

one odd thing i noticed was when i open network settings again after finishing, the secondary dns field is blank. only the primary dns is saved.

i changed the mtu settings like u said in a previous post in this topic.

PS: just installed windows xp which means i ruined grub. i need to recover it.
havent yet done that. else i would’ve given the complete steps as to how i connect to internet and how i changed mtu settings.

11

This might help you get openSUSE running and booting again:
GRUB Boot Multiboot openSUSE Windows (2000, XP, Vista) using the Grub bootloader.

12

just as a matter of interest:

if you can run an openSUSE Live CD and it will hook to the internet,
then your install should be as automatic…

(well, the last time i made an install all i had to do was click next
next next whenever i was in that section of the install that deals
with networking…and, it all JUST WORKS…)

–
tertiary

13

thanks.
i’ve been to your site already :slight_smile:
yeah. i click on links in siggys

14

Yast -> Network Devices -> Network Settings
the network settings window has 4 tabs.
1.The 2nd tab is active (Overview Tab) :
the top part shows

the device VT6105[Rhine-III] and the IP Address 192.168.1.100

the bottom half

  p, li { white-space: pre-wrap; }  VT6105 [Rhine-III] 
MAC : 00:19:5b:82:31:bc

 


  - Device Name: eth0
  - Will not be started at all
  - IP address: 192.168.1.100, subnet mask 255.255.255.0

on that same tab clicking on “edit” brings up “Network card setup”
there i select the radio button labelled “Statically assigned IP Address”
and enter IP Address provided by my ISP (192.168.1.100)
subnet mask 255.255.255.0
the hostname field i leave as it is (localhost)
on the “General” tab i set the MTU

coming back to Network settings window
on the “global options” tab i haven’t changed anything.
i.e., Network setup method : User Controlled with NetworkManager
Enable IPv6 is checked
DHCP Client Options
Request Broadcast Response is unchecked
DHCP Client Identifier is blank
Hostname to send is “AUTO”
change Default Route via DHCP is unchecked
on the Hostname/DNS tab
Hostname : localhost
Domain Name : localdomain
write hostname to /etc/hosts is unchecked

Name Server 1 is 192.168.1.1
Name Server 2 <whatever i enter here doesnt get saved>

Routing Tab
Default Gateway : 192.168.1.1

almost forgot. used your website to recover grub.
thanks

15

Change “will not be started at all” to start at boot.
And for a fixed IP 192.168.1.100 and a gateway 192.168.1.1 you should use the checklist represented by Pics 1, 2, 6, 7, 8 and 9 of this tutorial:
HowTo Configure a network card in Suse/openSUSE 10, 11 for LAN and Internet Access.

16

did as u suggested. working fine now.
thank you all, especially swerdna.
thank you very much.

now to explore suse :slight_smile: