Internet

[monty]

Every so often our internet connections go a bit haywire

Like today, some websites come in lightning (well, relatively speaking anyway ) fast, while others simply time out.

Strangely enough, pinging the trouble websites indicates no problems, with pretty low latency and no packet loss at all.

Today, Yahoo works perfectly and google simply cannot get accessed. DNS resolves, pings com in at under 300 msec, but no data at all comes through. After a while I just get a "network error" page.

Wondering why 32 byte pings (standard ping) fly back and forth normally, but bigger chunks of data, like real webpages, don't come through, I started to play a little with the ping commands.

With the -l parameter one can increase the ping packet size, and I found out that the pings keep flying around until 1465 bytes of size is reached. Then suddenly all response stops.

When pinging the websites which do work properly, pings of several thousands of bytes fly back and forth without any problem whatsoever (today, both Yahoo and thaivisa)

So, any hints from the network wizards out there???

[A_Traveller]

Was mentioned to me in passing last week that some 'activity' was going to be undertaken over the weekend by at least three of the main providers. They are supposed to be upgrading focusing on business provisioning, and so are taking advantage of the scheduled long weekend.

May have no relevance but FWIW.

Regards

[monty]

Example, I can't access google today, so I do my little ping test, first with 1400 bytes, then with 1500 bytes:

C:\Users\Erik>ping -l 1400 www.google.com

Pinging www.google.com [66.249.89.104] with 1400 bytes of data:

Reply from 66.249.89.104: bytes=56 (sent 1400) time=370ms TTL=236

Reply from 66.249.89.104: bytes=56 (sent 1400) time=372ms TTL=236

Reply from 66.249.89.104: bytes=56 (sent 1400) time=377ms TTL=236

Reply from 66.249.89.104: bytes=56 (sent 1400) time=379ms TTL=236

Ping statistics for 66.249.89.104:

Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),

Approximate round trip times in milli-seconds:

Minimum = 370ms, Maximum = 379ms, Average = 374ms

C:\Users\Erik>ping -l 1500 www.google.com

Pinging www.google.com [66.249.89.104] with 1500 bytes of data:

Request timed out.

Request timed out.

Request timed out.

Request timed out.

Ping statistics for 66.249.89.104:

Packets: Sent = 4, Received = 0, Lost = 4 (100% loss),

C:\Users\Erik>

As can be seen, 1400 bytes gives no problem, pretty normal latency for Thailand and no packet loss. ping with 1500 bytes, and nothing goes through

Now, Thaivisa is working OK today, so the same test:

C:\Users\Erik>ping -l 1400 www.thaivisa.com

Pinging thaivisa.com [203.174.84.82] with 1400 bytes of data:

Reply from 203.174.84.82: bytes=1400 time=222ms TTL=51

Reply from 203.174.84.82: bytes=1400 time=223ms TTL=51

Reply from 203.174.84.82: bytes=1400 time=229ms TTL=51

Reply from 203.174.84.82: bytes=1400 time=229ms TTL=51

Ping statistics for 203.174.84.82:

Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),

Approximate round trip times in milli-seconds:

Minimum = 222ms, Maximum = 229ms, Average = 225ms

C:\Users\Erik>ping -l 1500 www.thaivisa.com

Pinging thaivisa.com [203.174.84.82] with 1500 bytes of data:

Reply from 203.174.84.82: bytes=1500 time=238ms TTL=51

Reply from 203.174.84.82: bytes=1500 time=244ms TTL=51

Reply from 203.174.84.82: bytes=1500 time=250ms TTL=51

Reply from 203.174.84.82: bytes=1500 time=253ms TTL=51

Ping statistics for 203.174.84.82:

Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),

Approximate round trip times in milli-seconds:

Minimum = 238ms, Maximum = 253ms, Average = 246ms

C:\Users\Erik>ping -l 5000 www.thaivisa.com

Pinging thaivisa.com [203.174.84.82] with 5000 bytes of data:

Reply from 203.174.84.82: bytes=5000 time=626ms TTL=51

Reply from 203.174.84.82: bytes=5000 time=626ms TTL=51

Reply from 203.174.84.82: bytes=5000 time=620ms TTL=51

Reply from 203.174.84.82: bytes=5000 time=621ms TTL=51

Ping statistics for 203.174.84.82:

Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),

Approximate round trip times in milli-seconds:

Minimum = 620ms, Maximum = 626ms, Average = 623ms

C:\Users\Erik>

Works perfectly, even with 5000 bytes!

P.S. the slightly higher then usual ping times is purely a result of the bigger packets being sent around...

[monty]

C:\Users\Erik>ping -l 5000 www.bangkokpost.com

Pinging www.bangkokpost.com [216.46.170.184] with 5000 bytes of data:

Reply from 216.46.170.184: bytes=5000 time=858ms TTL=43

Reply from 216.46.170.184: bytes=5000 time=860ms TTL=43

Reply from 216.46.170.184: bytes=5000 time=857ms TTL=43

Reply from 216.46.170.184: bytes=5000 time=859ms TTL=43

Ping statistics for 216.46.170.184:

Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),

Approximate round trip times in milli-seconds:

Minimum = 857ms, Maximum = 860ms, Average = 858ms

Bangkok post (hosted in the US) also no problems with big packets...

[RKASA]

What is our total set up PC and Cennection type. Could be alot of diff things. You may have pack size fixed large which does not alway work well. TZ connection tool would look at your setting with ref to how you are connected and suggest and make changes for you. It has my connection singing. Make sure you understand about resetting the connection setting which is just a button push, but to keep the orignal setting you must Always reset before tring new setting. Let me say again reset before using again every time. That way it knows the origanmal settings and the setting you tried do not become that which it resets to. Really it is a small and easy to use and free just google it.

PS it may resolve DNS but not every time because the server load changes by the minute. I use open DNS address one from the east US one west one in JP an AU have five plugged in none of which are the ISP or in Thailand where the servers can be q ing.

Edited August 11, 2007 by RKASA

[Tywais]

It's possible XP and your router MTU don't match. You can go here to see how to set your MTU for XP and see if you get any improvement.

http://www.dslreports.com/faq/5793

PS - your router should be set with the same MTU.

PPS - MTU means Maximum Transfer Unit

Edited August 11, 2007 by Tywais

[monty]

No DNS resolving problems, can be seen from the pings.

Same results with my ISP's dns servers and with opendns...

Was thinking about MTU settings etc, but this doesn't explain some websites working properly!

It's very reproducible as well, websites opening normally allow big ping packets, the websites timing out don't, although pings with smaller packets work perfectly.

I would love to find a way to do a tracert with bigger packets, this might indicate where our data gets eaten

AFAIK tracert only shoots the 32 byte packets to perform its task...

[RKASA]

That is what TZ connection does it looks at it tells what it is and why you should change it what it will be changed to and then you chose. step by step for any type of connect from dial up to T1

[Tywais]

Was thinking about MTU settings etc, but this doesn't explain some websites working properly!

Possibly the routers on the way to the different points have their own MTU settings. I still recommend trying to adjust your MTU using a problem site and following the instructions in the link. At least check what your XP MTU setting and ADSL router settings are.

[lopburi3]

I suspect Google.com may not be a good example. If I type in that name I am sent to Google.co.th and have to select Google.com from that page to actually access Google.com

[Tywais]

Might try this application > Net Speed Booster which can detect MTUs of routers on the way.

Also, here is the link to TZ Connection Booster as mentioned by RKASA > http://www.dirfile.com/tz_connection_booster_wizard.htm

[RKASA]

I suspect Google.com may not be a good example. If I type in that name I am sent to Google.co.th and have to select Google.com from that page to actually access Google.com

I know I hated that. After changing DNS set up I get what I type in not redireacted by thai server.

[RKASA]

Might try this application > Net Speed Booster which can detect MTUs of routers on the way.

Also, here is the link to TZ Connection Booster as mentioned by RKASA > http://www.dirfile.com/tz_connection_booster_wizard.htm

Yea thanks forget to ref it. and TZ does that to. thats why big MTU not always best let it resolve the trace route for you. I fear that most your Prob may just be ADSL I keep hearing the same story and seeing the mess on the power poles I am glad that I am not connected to it.

[digitele]

Monty,

if nothing has changed in your configuration;PC, router, line etc. and it worked fine before..

I would guess it's a router issue (enterprise router Cisco, Jupiter) along the way.

Also, if someone was to schedule work it would be during a long weekend (you'd think)

I wouldn't start second guessing my setup. It really sounds like enterprise equipment along your path.

Regards

[RKASA]

I was thinking that it has been a long term problem. Not just this weekend. If it norm works fine should not be a prom. Good thing about the booster is it keeps the first setting and just check back to what it was. In fact you need to do that before changing the setting again or the current settings become the back up. You can also jot down the was settings as you go thou and know what to set manual if necessary in the future. Even if just picking your own setting it is simple to use the TZ just as an interactive editor of connection settings.

[monty]

My router's mtu is set at 1492, but no idea how to change the mtu on Vista! All these lovely programs won't work with Vista (they don't indicate any MTU value anyway, probably a different registry location in Vista).

It's definitely on the way somewhere, since normally my ADSL performs nicely!

I just would love to find a way to see where along the way the problem is, for starters to see wetter it's at my ISP's routers, or (more likely) the CAT's IIG routers!

Just to decide to call my ISP and shoo them in action, or to just wait till the CAT clears their problem.

[RKASA]

It won't be long they will update the boosters then you can browser it without changing anything and see what all the current setting are. 1492 is norm. There are two MTU if that one is 1492 the other is 1500. Its req that the one is set alittle smaller then the other. but the set up has a s/w that enables or disables the auto ajusting of the mtu for each connection made and it would be good to know that it is set. Maybe someone knows the way to check it in vista.

[ilCapitano79]

I had this same problem today, never happened before but not only for google i had this problem with channel4.com as well but all other sites were working perfectly fine.

I also after a while get that tcp ip or something like that network error.

[endure]

I've tried using TZ Connection but I only get the left hand half of it on my PC. I'm using XP SP2 1680x1050 res on a 22" widescreen Dell display. Any ideas why I don't get it all?

[RKASA]

I've tried using TZ Connection but I only get the left hand half of it on my PC. I'm using XP SP2 1680x1050 res on a 22" widescreen Dell display. Any ideas why I don't get it all?

Only get the left half? the program or the web sites? Program uninstall reinstall its crupted Web sites not rendering check your browser

[endure]

I've tried a re-install but same same. This is the only part of the program that I can see:

[RKASA]

Wild that is a new version must have a crupted download or the new one got a problem can you get this attachment it the old one. oh no can't upload .exe forgot. let me check around for a location toput it up at.

[RKASA]

I downloaded and installed the new version it has the same name as the old its 4mb and the old was only 560K. The skin for the new program is using some kind of flash, but it looked and worked fine for me. If you can't get a replacement download to work try this jpg which was a exe in a former life. well that didn't work ether attachment failed. worse case my profile has email address shoot my a line and I can attach it to reply.

[drake]

following Links can help to find com-probs:

MS Connection test:

http://www.microsoft.com/windows/using/too...gd/default.mspx

TCP/IP Analyzer:

http://www.speedguide.net/analyzer.php?DAT...tamp=1186923309

Change Registry's MTU/RWIN:

http://www.annoyances.org/exec/show/article04-006

cu drake

[RKASA]

Got your message. attachment and reply sent. I think the flash they are using for the new skin on the program is causing the problem the old one is vary basic style as you can see it is 3.5mb smaller. But all the same settings and reasons for suggested setting are in the old prog. they do the same thing. Ran both and checked.

Edited August 13, 2007 by RKASA

[Prasert]

Every so often our internet connections go a bit haywire

Like today, some websites come in lightning (well, relatively speaking anyway ) fast, while others simply time out.

Strangely enough, pinging the trouble websites indicates no problems, with pretty low latency and no packet loss at all.

Today, Yahoo works perfectly and google simply cannot get accessed. DNS resolves, pings com in at under 300 msec, but no data at all comes through. After a while I just get a "network error" page.

Wondering why 32 byte pings (standard ping) fly back and forth normally, but bigger chunks of data, like real webpages, don't come through, I started to play a little with the ping commands.

With the -l parameter one can increase the ping packet size, and I found out that the pings keep flying around until 1465 bytes of size is reached. Then suddenly all response stops.

When pinging the websites which do work properly, pings of several thousands of bytes fly back and forth without any problem whatsoever (today, both Yahoo and thaivisa)

So, any hints from the network wizards out there???

Nice!

So I wasn't the only one experiencing this problem

I finally found out about this when we got some additional adsl lines that only support PPPoE (Fox DSLAM). Hardly any traffic went through - peer2peer worked fine, webtraffic was hel_l.

The solution: adjust the maximum-segment-size to 1452 - works on TOT and TT&T

how-to-adjust this: depends on your router. on Cisco with an adsl interface:

interface Dialer1

ip tcp adjust-mss 1452

The cause: blocked icmp traffic.

Normally when a package is too large to be transported over a link, it is fragmented into 2 packets, except when the package has the DF-bit set (Don't Fragment). In that case, the router sends an icmp package back to the sender with the message that it must adjust the size of the package.

But....the majority still thinks that pings are bad and dangerous, so they simply block ping (ping uses 2 types of icmp packages). And that's happening at a lot of firewalls and routers.

[RKASA]

I think the only prob with that is now you have a fixed MTU. and if you know the hack you can set windows to adjust to trace route which allows it to work best for any connection. So the program checks current setting and gives choices and reason for suggested setting and does the reg. hacks for you. No hassle. It also stores last settings if you like to go back.

Oh sorry I see you do have DF in your post. Just suggesting that little program makes it fast and easy for novice to get good results.

Edited August 14, 2007 by RKASA