Extremely Slow Internet with Leopard

[eightmedia]

yeah man! I think the dns servers is not the right way to look after. I replaced them and I don't really see a big change. The pc is even slower with the new ones.

I tried to update my router firmware but can't seem to get the right file to do that. Also it gives me errors when I try to setup the Mac filter. I'm gonna call telefonica monday and ask them for a new router, and I don't want that Xavi 7868r again

I also took my laptop to a hotel near my place and logged in to their wireless network and I had no problems. My MBP was as fast as it was in Belgium. After that, I took the Macbook Pro to a friends house here who also uses telefonica and has the same router we have at our place and it was slow again. So i'm starting to think it's all the routers fault.

I'm really going crazy here, lost a lot of my precious time and can't get my work done properly. And I'm really out of options .. don't knwo what to do next

[Las_Vegas]

What did you replace your DNS servers with? On my systems I manually added the DNS servers my IP uses into the TCP/IP settings. By doing so, I never have a problem with them. If your router doesn't list them in the Status section, contact your ISP. They will be glad to give you the server addresses (likely 3). Put them in the DNS field of your Network preference pane's TCP/IP settings separated by commas.

[drsmartz]

ssibayan, wow, I am having the exact problems you are having. Different hardware though - i have the dual G5 tower. I'm only on ethernet. I have a PC connected to the same router, and the PC is as fast as always, so I believe that eliminates my ISP, etc.

Changing DNS, and add/removing profiles did not work when I was on 10.5.1. 10.5.2 didn't improve this the sluggishness (though I haven't tried add/remove profile nor openDNS "fixes" yet). Also, tried updating firmware of router, and that did not fix the problem.

Interesting finding. On speedtest.net, I get the following result:
10.5.2, Firefox: 1534 kbps down, 34 up, 342 ms ping! (upload takes a long time to start)
10.5.2, Safari: 1529 kbps down, 46 kbps up, 258 ms ping.
WinXP, Firefox: 1522 kbps down, 347 kbps up! , 184 ms ping.

[drsmartz]

debug_http results:

debug_http www.apple.com
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100  9926  100  9926    0     0    648      0  0:00:15  0:00:15 --:--:--  163k
name lookup: 15.170 connect: 15.200 pretransfer: 15.200 starttransfer: 15.243 total: 15.296

Then I try again, to yahoo:

debug_http www.yahoo.com
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100  9533  100  9533    0     0  23538      0 --:--:-- --:--:-- --:--:--  140k
name lookup: 0.285 connect: 0.308 pretransfer: 0.308 starttransfer: 0.345 total: 0.405

The name lookup is erratic. Sometimes it works, sometimes it doesn't.

[JBoisen.com]

Hi.

I've got the exact same problem.
Under network->dns I have my airport extreme's ip listed as the first dns service ip. Because the router is listed first, requests will be made to the router before any other dns service manually entered.
I simply altered both of the DNS ip's in the airport setup to my own wan ip's so that dns requested performed via the router would be denied immidiatly. Prior to this I entered the dns ip's from the airport in to my dns settings under systempref.->network->dns.
Voila! It works. FAST.

Hope it works out just as easy for you guys.

Why the dns lookup via airport express is rubbish i don't know but it sure is sad...

[rdhints]

ssibayan & eightmedia:

You're likely right with regards to routers being at fault with respect to slow internet access under Leopard. Many routers don't respond to SRV DNS requests. And this is the type of DNS record Leopard asks for first, before retrying with A record requests after multiple failures/timeouts on SRV record requests.

Switching to a different router that does handle these requests, can make a large difference in browsing speed, which is exactly what you're seeing.

Same goes with IPv6 DNS requests (if you're using Firefox).

Quote: Originally Posted by eightmedia yeah man! I think the dns servers is not the right way to look after. I replaced them and I don't really see a big change. The pc is even slower with the new ones. I tried to update my router firmware but can't seem to get the right file to do that. Also it gives me errors when I try to setup the Mac filter. I'm gonna call telefonica monday and ask them for a new router, and I don't want that Xavi 7868r again I also took my laptop to a hotel near my place and logged in to their wireless network and I had no problems. My MBP was as fast as it was in Belgium. After that, I took the Macbook Pro to a friends house here who also uses telefonica and has the same router we have at our place and it was slow again. So i'm starting to think it's all the routers fault. I'm really going crazy here, lost a lot of my precious time and can't get my work done properly. And I'm really out of options .. don't knwo what to do next

Quote: Originally Posted by ssibayan Sadly, my 18 seconds fluctuates now from 11 seconds to 70 seconds with every change I attempt! I just thought of something - I checked my Network properties on the PC, which is on the same network as my macs, and the DNS servers listed on the PC are: 80.58.61.250 80.58.61.254 Anyone who has been following this saga from the beginning, will read that those were the very first DNS numbers my Mac also generated (makes sense). One user replied and said there was significant packet loss on one of those, so I have been trying to find replacement DNS numbers ever since. But if those DNS numbers are the ones my PC is pulling... and the PC is working flawlessly (in terms of internet... in terms of anything else, well, that's why I have macs :P), then it seems like I am going down the wrong path. Any thoughts?

[grubinski]

I had issues on my wife's iMac. Changing the DNS servers didn't do anything, even when I ran a DNS server *on her machine*, which returned queries in 0mS once it had resolved a name.

Here is my documentation of the solution. The summary is that once I started running all her traffic through a SOCKS proxy to my firewall, using ssh for the proxy, the problems are completely gone.

http://www.grubinski.com/hints/leopard.networking.html

Mike

[Las_Vegas]

Did we really need that response twice in a row?

[JBoisen.com]

I'm not sure if that reply was meant for me.

But if it was then yes, you do need my reply.

The thing that screws it up with an airport extreme and a osx machine is that osx will list the airport as the first DNS server. The airports lan IP is also greyed out, so that it can not be removed. This in effect means that entering more dns servers will not help you unless you make sure that the airport isn't able to process any dns requests, because osx will make dns requests to servers in the order they appear on the list found under systempref.->network->advanced->dns.
The dns requests to the airport can be made faulty by altering the DNS IP's listed under the Internet tab in the airport extreme, the IP addresses are greyed out but just click on them and enter the airport wan IP in both primary and secondary DNS.
When this is done osx will, when looking up a web address, first contact the airport router, the airport router will relay the request to the IP entered in its DNS config. This will however make it contact itself and the request will be denied at once, osx will then move on to the DNS server listed as the next one, this then does not involve the airport router because request are made directly to dns server. Speeding things up drastically.

Haven't seen this solution offered before, but i sure works for me... I even entered the same DNS IP addresses in osx as the airport was using as default.

[muso]

I've put together a simple and hopefully easy to read guide for this over on mac-forums - http://www.mac-forums.com/forums/sho...d.php?p=607373 but basically all that you've gotta do to fix the problem is bypass any automatically assigned dns servers on any routers or modems on your network, then specify your own ones (eg opendns, or your isp's ones).

[Choppaface]

Something happened with Mac OS X's low-level DNS resolving functions during the development of Leopard and now a variety of applications are screwed up. I'm also seeing this problem, as well as the "slow SSH problem." I think we're just going to need to wait till Apple does something about it. Since the problem appears to be somewhat dependent on what kind of servers are running on your network, this was probably not something they could figure out during the Q/A phase of finalizing Leopard, tho I'm surprised the Beta seeds didn't reveal this issue...

Related to "slow SSH connect" issue with leopard:
see http://discussions.apple.com/thread....55437&#6655437

Quote: "Assuming you are referring to problems when ssh-ing from a Leopard box to other systems, then the problem is probably the new behavior of the getaddrinfo() call in Leopard. Basically, that call in Leopard now uses the RFC-recommended practice of first issuing a DNS SRV record request rather than an A record request, and then falling back to the A record request if the SRV request fails; unfortunately, apparently a lot of DNS servers don't respond to the SRV request w/ an NXDOMAIN as they should, and instead just drop the request, so getaddrinfo() retries the SRV request a few times, and only after those requests time out does it try to A request. So if ssh is using getaddrinfo() rather than gethostbyname/getservbyname, then you it would hang like you describe whenever you are pointing to a DNS server that doesn't respond well to the SRV request. (There are also reports that Leopard may generate DNS requests w/ an invalid RR type, which might explain why the servers being queried aren't responding to them correctly.) The easiest way to check if that's your problem would be to sniff traffic on port 53 while trying an ssh connection, and seeing if your box is making a SRV request or an A request. (If that is in fact your problem, you may be SOL until a patch is released, as Googling, I don't see any solutions other than hacking individual apps to use gethostbyname() instead of getaddrinfo().)" (A reader responds) I did monitor port 53 and it is making SRV requests.

[Choppaface]

See this page

http://blog.jungledisk.com/2007/10/3...d-work-around/

[f21]

Try turning on the UNIX Name Service BIND (Berkeley Internet Name Domain) via root terminal. It's built into OSX (as OSX is UNIX based) but off by default (not sure about Leopard) for some odd reason, but it's the UNIX native DNS. Well it's actually a suite of UNIX based utilities including nslookup and dig but contains a very good DNS server that may fix your problem if it's DNS related.

[agentx]

F21 if you are referring to my comments....it is not practical to have the 20 client machines running a local DNS server and having a main DNS server on network as well.....so it will not help.

As far as running on my own local machine, i have reasonable experience with DNS setup so may have a go, but something is up with the WIFI.....full stop.

Since rolling back Airport/IO80211.kext drivers to the 10.4.9 version things have been better coupled with my laptop pinging router every 2 seconds....not ideal but it is keeping things mildly in order.

[arbushell]

Just for info the first DNS servers inquired are those at the bottom of the list (normally added manually, as OpenDNS). This for sure if those at the top are grayed. Seen with Wireshark packet trace and Camino.

[rdhints]

I not sure if I can confirm what you say, arbushell, although I'll confirm tomorrow.

According to tcpdump, this is not true. The order that DNS servers appear in the list, from top down, is the order that the servers are used.

The greying out of servers simply means they are not removable from the list, not that they are "unused".

Another way to tell is by looking at service order using ncutil or scutil.

Again, will write more later.

Quote: Originally Posted by arbushell Just for info the first DNS servers inquired are those at the bottom of the list (normally added manually, as OpenDNS). This for sure if those at the top are grayed. Seen with Wireshark packet trace and Camino.

[rdhints]

Setup tcpdump as follows: sudo tcpdump -i en1 -s 128 port 53

(use en0 if you're on ethernet).

Open up another terminal window and enter this:
curl http://wiifit.com

This will load the web page using "curl".

The following is a printout from tcpdump showing resolver1.opendns.com as the DNS server.

tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on en1, link-type EN10MB (Ethernet), capture size 128 bytes
21:09:25.347972 IP 192.168.1.132.52104 > resolver1.opendns.com.domain: 8973+ SRV? _http._tcp.wiifit.com. (39)
21:09:25.413867 IP 192.168.1.132.52105 > resolver1.opendns.com.domain: 51611+ PTR? 222.222.67.208.in-addr.arpa. (45)
21:09:25.468237 IP resolver1.opendns.com.domain > 192.168.1.132.52105: 51611 1/0/0 PTR resolver1.opendns.com. (80)
21:09:25.471433 IP 192.168.1.132.52106 > resolver1.opendns.com.domain: 51254+ PTR? 132.1.168.192.in-addr.arpa. (44)
21:09:25.522641 IP resolver1.opendns.com.domain > 192.168.1.132.52106: 51254 NXDomain 0/0/0 (44)
21:09:25.644452 IP resolver1.opendns.com.domain > 192.168.1.132.52104: 8973 NXDomain 0/0/0 (39)
21:09:25.644965 IP 192.168.1.132.52107 > resolver1.opendns.com.domain: 49725+ SRV? _http._tcp.wiifit.com. (39)
21:09:25.698514 IP resolver1.opendns.com.domain > 192.168.1.132.52107: 49725 NXDomain 0/0/0 (39)
21:09:25.699892 IP 192.168.1.132.52108 > resolver1.opendns.com.domain: 38658+ A? wiifit.com. (28)
21:09:25.832046 IP resolver1.opendns.com.domain > 192.168.1.132.52108: 38658 1/0/0 A 205.166.76.53 (44)
21:09:26.526985 IP 192.168.1.132.52109 > resolver1.opendns.com.domain: 18132+ PTR? 53.76.166.205.in-addr.arpa. (44)
21:09:26.881751 IP resolver1.opendns.com.domain > 192.168.1.132.52109: 18132 NXDomain 0/0/0 (44)

And finally, attached is a screenshot of my DNS servers listed. Notice how 192.168.1.1 is listed after the opendns server, yet it's never even tried by Directory Services' DNS resolver?

I can't say everyone's Mac behaves exactly the same as mine, but, this is my evidence that DNS servers are used in order that they are displayed within Network Preferences pane / Advanced / DNS screen.

Camino and Wireshark are, in my opinion, far removed from the actual action of DNS lookup and thus are not good tools for diagnostics. Remember that Camino has a dns cache that it tries before asking Directory Services (DS), and if you've visited a site within the last minute, it won't ask DS to do a lookup and may make Wireshark produce ... misleading results.

What do you think?

Regards,
Ben

Quote: Originally Posted by arbushell Just for info the first DNS servers inquired are those at the bottom of the list (normally added manually, as OpenDNS). This for sure if those at the top are grayed. Seen with Wireshark packet trace and Camino.

[cwtnospam]

This link may explain part of the problem:
http://hunter.pairsite.com/blogs/blog20080603.html

[arbushell]

cwtnospam
Wireshark (ex Ethereal) simply records and shows TCP and other kind of packets flowing on the connection and likely is layered over tcpdump, I don't think it messes the order of messages (I'm using WS on MAC just for continuity with Windows).
In any case I repeated the test with Safari and tcpdump, results are been the same: Leopard 10.5.3 (former test was with 10.5.2) sends the first A Query to the first non-router assigned DNS (that is the first non-grayed, in my case OpenDNS 208.67.222.222, set manually with networksetup -setdnsservers ... ....). The same happens with the terminal command 'dig' instead of Safari.
Very interesting the hunter.pairsite blog, probably most DNS issues are due to this comprised mine that in the past addressed me to try OpenDNS and other name servers available on the internet

[rdhints]

Arbushell, I think we may have just discovered something...

I believe Apple has reversed the order of the DNS server priority in Leopard 10.5.3.

I'm only speculating here as I have 10.5.2 installed and you have 10.5.3 installed, we're running roughly the same tests, yet you're seeing the opposite of what I'm seeing. Easiest explanation of that: Apple changed DNS server order with Leopard 10.5.3.

There is logic behind this from my perspective: If a user spends the time to add a DNS server manually to their TCP/IP setup, wouldn't they want it to actually be used?

The way Apple had it setup before (10.5.2 and prior), any DNS server you added would have no effect until the ones listed above it were tried/failed. Adding a preferred DNS server in Leopard 10.5.2 required creating a new Network Location, vastly more complicated then simply opening up the DNS tab and adding an IP address.

Anyone else able to confirm what order their DNS servers are used and under which version of Leopard? (Using tcpdump and curl as shown in post 56)