Member Avatar for bachack

I am not able to load the yahoo sites (yahoomail, yahoo,yahoo answers etc) and few other sites(eg Microsoft.com).
Please refer to my earlier post :
http://www.daniweb.com/hardware-and-software/networking/threads/409045/cannot-access-yahoo-sites
I had a Beetel 450TC1 router, which finaly gave up yesterday, so I used the modem that my ISP provided, a wire-only router (AN1020-20) and these sites were working. So I got a new router - TP-LINK, TLWR740N, and the issue is back.
I have a desktop, that is connected through wire to the router, a laptop, a tablet and a few handsets that connect wirelessly to the router. None of these devices can browse the yahoo sites.
I can still access the sites through the wired router(AN1020-20) on the desktop and laptop, and can access the sites on the handheld devices through 3G.
I have done all the troubleshooting I could think off....
- I have Changed the DNS to the google public dns, this loads the yahoomail page partially, but after providing the credentials, the page keeps loading.
- Turned off firewall, no success.
- Turned off the UPnP, no success.

Please help.

  • 7 Contributors
  • 9 Replies
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  • 11 Months Discussion Span
  • Latest Post Latest Post by smitshah27

Dani AI

Generated

Brief diagnosis and what likely happened

The symptom reported by — ICMP/ping works but some web sites (HTTPS) stall when the TP‑LINK TL‑WR740N is in the path — matches a classic Path MTU / fragmentation problem (a PMTU “black hole”) or a router TCP/MSS handling bug. Several TL‑WR740N threads and TP‑Link KB entries describe cases where some sites only work when the client is connected directly to the modem; router-level MTU/MSS or WAN‑binding features are a common root cause. (rfc-editor.org)

Quick, non-destructive checks (what to run and what to look for)

  • Test path MTU (Windows):

    ping -f -l 1472 www.yahoo.com

  • Test path MTU (Linux/macOS):

    ping -M do -s 1472 www.yahoo.com

  • Check a TLS handshake from a terminal:

    openssl s_client -connect www.yahoo.com:443 -servername www.yahoo.com

Watch for the Windows error “Packet needs to be fragmented but DF set” or ICMP Destination Unreachable (type 3, code 4) in a packet capture; those indicate a PMTU/fragmentation issue. The Windows ping options and the DF test pattern are documented in Microsoft and networking guides. (learn.microsoft.com)

Likely fixes and why they work

  • If the DF‑test shows fragmentation failures: either enable MSS‑clamping on the router or reduce the WAN MTU so TCP peers never send packets larger than the path allows. Routers and firewalls commonly offer an MSS‑clamp or MTU setting; iptables and router vendors document the clamp approach as a PMTU workaround. Allowing ICMP “Fragmentation Needed” messages through the firewall also lets PMTU discovery work normally. (docs.hetzner.com)

  • TP‑Link specific: TP‑Link support articles list MAC‑clone and MTU checks as troubleshooting steps for “some sites only” problems; updating firmware and disabling any “hardware NAT/acceleration” features (if present) are sensible follow‑ups. (tp-link.com)

Context for the thread

’s firmware suggestion and the later note from (that changing the router MTU resolved his case) are consistent with the PMTU explanation above; the diagnostic commands listed here help confirm whether that same mechanism caused the original failure. If the tests show no DF/ICMP failures, a packet capture of the failed TLS session will usually reveal whether the router is dropping or mangling packets.

Recommended Answers

All 9 Replies

Member Avatar for CimmerianX

Check the routers for the newest firmware just to cover any software bugs.

Turn off all Intrustion Detection systems on the router (if any).
Turn off all firewall features on the router (if Any)
Remove any blocked keywords if your router has that feature (remember block the word 'sex' and www.marsexplorer.com will also be blocked.

Member Avatar for bachack

I have tried these.....but still no success....

Member Avatar for bachack

Just found that there was a Diagnostic Section in the Router's page, which allows to ping and traceroute.
I pinged www.yahoo.com,and the result is pasted below :
Pinging www.yahoo.com [72.30.38.140] with 64 bytes of data:

Reply from 72.30.38.140: bytes=64 time=335 TTL=49 seq=1
Reply from 72.30.38.140: bytes=64 time=434 TTL=49 seq=2
Reply from 72.30.38.140: bytes=64 time=341 TTL=49 seq=3
Reply from 72.30.38.140: bytes=64 time=371 TTL=49 seq=4

Ping statistics for www.yahoo.com
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milliseconds:
Minimum = 335, Maximum = 434, Average = 370

Out of curiosity I pinged www.yahoo.com from the command promt and the result is :
C:\Users\Chetan>ping www.yahoo.com

Pinging any-fp3-real.wa1.b.yahoo.com [72.30.2.43] with 32 bytes of data:
Reply from 72.30.2.43: bytes=32 time=310ms TTL=49
Reply from 72.30.2.43: bytes=32 time=310ms TTL=49
Reply from 72.30.2.43: bytes=32 time=310ms TTL=49
Reply from 72.30.2.43: bytes=32 time=313ms TTL=49

Ping statistics for 72.30.2.43:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 310ms, Maximum = 313ms, Average = 310ms

I am really clueless at this point,i can successfully ping the sites but cannot browse them...
serious help needed!!!

Member Avatar for thelostboy

What is your current OS that you are running on the computer?

Have you tired accessing the sites using hexidecimal or binary this can sometimes identify some ossue with the name resolutions and can also help you see if it your router that is locking them for any reason?

Member Avatar for bachack

Hello Guys,

Finally Solved the Issue.

Member Avatar for patouyou

please bachack. What did you do to solvethat problem. I am ahving the same issue, not being able to access secure sites with tl-wr740n. thanks in advance

Member Avatar for Member #5309

I was interested in the answer to this problem also. I have to do frequent work on different types of routers. Friends, family, aquaintances, etc. Including my own network modem/router on which I have 4 pc's. Two wired and two wireless. I thought finding and joining this site was a great move forward for learning, sharing, solving pc tech problems. But it seems some do not like to share.

Member Avatar for jyotsna01

i think beetal do not provide that good net connecting services..
use tata docomo or internet connections..!!

Member Avatar for smitshah27

go to 192.168.1.1 or 192.168.0.1 whchever is der for you

then go to network -> WAN -> advance -> Change the MTU size to 576 then save it and reboot it

hope this will work. This is workd fr me.

Email me if the result is positive - smitshah27031987@yahoo.co.in

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