I too have a slow DNS lookup problem with SuSE 9.3 and all the posted fixes - the main one being at

//portal.suse.com/sdb/en/2003/10/90_mozilla_ipv6.html]SuSE site - slow internet access

- have not helped.

The main symptom is a slow (5-10 second) initial site lookup. Once the site is found, access is fine. If I ping the site by name it takes 5-10 seconds before the actual transmissions start. If I ping the site by its ip address, the ping transmissions begin immediately. The ipv6 solutions do not work for me.

I have a dual boot setup and I only have this problem on the linux side. The winxp-pro side is fine (no lookup delay) so the problem must reside somewhere in SuSE 9.3. Any help would certainly be appreciated.

When I installed 9.3, it set my primary DNS address to my DSL modem for some strange reason. Once I set the primary DNS to a real server, things speeded up considerably. However, when I initially fire up a web browser it still takes several seconds for my home page to load the first time.

The DNS address has been correctly identified by my configuration so that's not the problem. At startup or when I switch to a new site my response is on the order 10 seconds - I could live with 2.

My internet response slowed to a crawl when I switch from a direct connection form my cable modem to my PC ethernet card to a cable modem to linksys router to ethernet card connection. Below is what I found.

I am using Mandriva LE2005 accessing the internet via a cable modem through a LInksys access point router. I did some research on ipv6 using google and linuxquestions.org. A number of post around the web described the same symptoms.

From those post there were two reoccurring themes:

1. a conflict with the new ipv6 Internet protocol (most common)
2. and a DNS priority or order problem

First I updated the firmware on my LInksys BFEW11S4 router.

No improvement but I needed to do this anyway according to linksys.com.

Then from theme #1 and verbatim from the link

http://www.linuxquestions.org/questi...highlight=ipv6

I performed the operations below:

“Okay, this worked for (susi) 9.3! Turn off IPV6 support using this procedure.

In a terminal window run (su to root):
then type
#echo "alias net-pf-10 off" >> /etc/modprobe.conf (Enter) #echo "alias ipv6 off" >> /etc/modprobe.conf (Enter)

Then, in the address line of FF enter:
about:config
(no spaces)
next in the filter line enter:
ipv6

double click on
network.dns.disableIPv6 to change value from "No" to "Yes"

close FF and restart computer

When the computer reboots you should see significantly faster DNS lookup by FireFox. There are some other FF tweaks that may help even more but this was the "biggie". “

There was no improvement. Many other post indicated the same after similar exercises. Cleaning up, I undid it all.

Concerning theme #2, I found the suggestion below:

“Check what nameservers (DNS-servers) you use in windows and Linux. In Linux these settings are stored in /etc/resolv.conf.

My first bet is that you have windows configured to fall back on a secondary nameserver if the first one is slow.”

At a Windows command prompt “ipconfig /all” gives among other info the DNS servers:

200.69.188.186
200.69.188.185
207.69.188.185

In that order. This information is handed off to the computer by the router which obtains it automatically from the ISP. So its no surprise that when I check the /etc/resolv.conf I found:

search earthlink.net
nameserver 200.69.188.186
nameserver 200.69.188.185
nameserver 207.69.188.185

Remembering a phone conversation earlier with earthlink network rep where I
asked what the DNS server addresses were. From my notes she told me:

207.69.188.185
200.69.188.186
I didn't get the 3rd as the phone connection was bad but it must have been 200.69.188.185

in that order.

On a whim I put 207.69.188.185 on top in my resolv.conf and with no reboot the internet access became instantaneous.

I tried a number of websites I commonly visit. Each one pop up instantaneously; faster, even, than in Windows Internet Explorer.

The only problem is when I reboot the resolv.conf is reset to the old order. I need to get my router to assign the DNS’ s in the order I desire. Also, if it is faster to assign the nameservers with the 207 on top why isn’t that done automatically? Is there a logic to the order they are assigned? If the 207 nameserver was assigned on top in Windows would Internet Explorer run faster? I don’t understand, which makes me fearful there may be adverse repercussions to the order I set. So far I haven’t found any.

Rock

Are you sure Windows is using DHCP (automatic config) like SuSE? I'd be willing to bet they're not configured the same way.... anyway, sounds like rocksniffer is on the right track. Your DHCP server is probably assigning two DNS servers and the first isn't resolving the address, causing a delay until DNS server #2 is queried. An easy solution would be to use a static address and enter the values manually so DHCP won't reconfigure the order everytime you bring up the interface. A better solution would be to tell the DHCP server to assign them in the proper order. And the best solution would be to firgure out why the first DNS server isn't resolving the address and fix the problem once and for all.

what does /etc/resolv.conf have for nameservers?

First, thanks for all the ideas. Unfortunately I still have not made any progress. My internet connection for both WinXP and SuSE uses a Linksys router that provides DHCP for both OSes. On the WinXP side the DNS servers are 24.2.10.33, 24.2.10.34, and 64.59.144.16 (in that order). On the SuSE side /etc/resolv.conf has the same 3 nameservers in the same order.

I also have eliminated Firefox as the problem by just using ping. On SuSE, if I ping www.google.ca it takest 7-8 secs before the actual ping transmissions start. If I ping 66.102.7.99 (the actual ip address for google.ca) the ping transmissions start immediately. On WinXP both pings start transmitting immediately.

On SuSE I have tried disabling IPv6, IPv6 and the firewall, and just the firewall but the above ping test always yields the same results. Any more ideas are welcomed as I have run out of them.

edit your etc/resolv.conf file and make the order of the nameservers as follows:

64.59.144.16
24.2.10.33
24.2.10.34

See what happens; no need to reboot. You can reinstall the IPv6 module. it is obviously not your problem.

rock

Hooray - changing the order of entries in resolv.conf as suggested by jackstoage corrected the problem! I'm assuming that means one of the 24.2.10.33 or 24.2.10.34 nameservers is broken and since all these are provided by my ISP then that means the best solution is to get my ISP to fix the problem. By the way, I did enable IPv6 before making the resolv.conf change.

Thanks.

Why it works remains a mystery, and when you reboot it resets everything. Why it's necessary is the big question. If someone knows the hows and whys and if there is a way to automate the process I would be interested in that.

It seems to take too long searching the first two DNS's before hitting the last and finding what it needs. The term flow control was thrown out as a possible cause.

Also, when my modem was directly connected to my computer there was no problem. That would point to the router as the cause. I need to reconnect that way and check for differences in the DNS list. Of course Windows never had a problem either way nor did any of the 4 other Windows boxes that access the internet through the router. Which points to a problem between the old Linksys router and Linux. i may need to buy a new router. Any suggestions would be helpful?

rock

Also, this is the first time I have been able to help someone else. I must be maturing.
rock

Well, here's the deal as I understand it. I talked to Linksys. While they don't support Linux I did query them about how their (my) router works. As all those who access the internet through a LAN know the router is setup to obtain an IP address automatically and so are each of the computers on the network. The computers do so because defaults as it should to become a DHCP server to the LAN. The cable or DSL modem passes the IP address and 2 or 3 DNS to the router and the router in turn as a DHCP server passes that onto each of the PC's on the LAN.

When I view my Linksys router’s web based configuration menu under the tab "Status" I can see the IP address and the 3 DNS given it by the modem. They are:

200.69.188.186
200.69.188.185
207.69.188.185

In that order.

Under the routers "DHCP" Tab it shows the IP address and DNS handed of to the computers on the LAN. By default the router only passes 2 of the 3 DNS on to the LAN; the first 2. There are spaces for 3 DNS on the page but only the first 2 are filled out with the first 2 addresses above the router assumes these are the primary and secondary DNS. It ignores the 3rd.

Given all that, I don't know how the 3rd DNS got into my /etc/resolv.conf except that I initially had the modem connected to the PC without the router. Later, through the router, Linux would edit the file as above. An nslookup on the addresses gives the results below:

200.69.188.186 186.fib188.gye.satnet.net
200.69.188.185 185.fib188.gye.satnet.net
207.69.188.185 ns1.mindspring.com

Satnet.net and various derivatives of it is a ISP that provides services to a number of foreign countries around the world. The first 2 DNS are likely their primary and secondary DNS. Mindspring .com takes you to the EarthLink website and is their primary DNS (personal communication).

There is still a lot unexplained, but, bottom line, the fix is to manually enter the 3 DNS to the spaces provided in the router's configuration DHCP page and I placed the 207.69.188.185 in the #1 DNS slot. On a new boot this will produce a /etc/resolv.conf with the DNS in that order and all is right in the world. The Windows computers on my network for some reason were never affected by the problem and never noticed the change. It just depends on your ISP and how your router works.

Hope this helps

rock

Windows has a client-side DNS cache. So the first time you queried the DNS server for that site it probably took just as long as with Linux. Subsequent lookups didn't query the DNS server at all however, pulling the info from your local cache instead.

Thanks to all the suggestions. I now have a workaround for the problem and a better understanding of what's going on. My workaround was to re-order the DNS servers in resolv.conf and update /etc/sysconfig to not change resolv.conf when I boot. It's not the best since it means my DNS list is hard coded. If I find a better solution, I'll post it.

Paul

Hi everybody!!

I'm new to linux so i'll be asking a lot of questions


Regarding slow internet with suse 9.3,i uninstalled lpv6 module using yast and after a reboot it's back to normal speed


40gb