Member Avatar for MtnBikerChk

Hi. I happened upon this site from a google search where people were having similar problems to me - but none exact.

I hope you can help (and I hope I put this in the right forum).

Here's the deal - I have SBCYahoo DSL and recently moved to a house with only 2 phone jacks. so I decided to get a wireless network card for my desktop, to use with my existing (and working) Linksys BEFSX41 Router and Wireless access point. I should add that I have always been using a wireless laptop and a wired desktop - both of which worked great.

Since I installed the wireless card, and upgraded the firmware on both the router and access point, I can surf some sites but not others. For example, I can get to fourms (like this one) and google, but not cnn.com or hotmail.

After I did some research, I thought it was an MTU issue. So I figured out what it should be and I enabled it on the router. That didn't help.

If I connect using the sbc software, I have no issues at all - except of course the one of not being behind the firewall.

any ideas??

THANKS!

  • 2 Contributors
  • 6 Replies
  • 122 Views
  • 4 Days Discussion Span
  • Latest Post Latest Post by MtnBikerChk

Dani AI

Generated

Useful follow-up to the troubleshooting already started by and — here are a few deeper causes and practical checks that often explain why some websites load while others stall, plus what to look for if reoccurrence happens.

Selective failures are frequently caused by path MTU/MSS issues or a broken NAT/inspection layer on the gateway. Path MTU discovery depends on an intermediate device being allowed to send "fragmentation needed" ICMP replies; if those are blocked, connections that require fragmentation will hang. Another common culprit is NIC offload features (large-send offload, checksum offload) interacting poorly with buggy router firmware. Application-layer gateway modules (FTP/RTSP ALGs) or aggressive stateful inspection can also drop or mishandle certain flows, producing site-specific failures.

A practical isolation workflow (no commands copied from earlier posts): test with a different network adapter or a wired connection to rule out the wireless card/driver; update or roll back the adapter driver if suspicious; temporarily turn off NIC offload options in the adapter properties and retest; capture failing sessions with a packet analyzer on the client and compare a working session. In captures, look for ICMP "fragmentation needed" messages, TCP SYN options showing MSS, repeated retransmits, or large packets with the DF (dont-fragment) bit set — those patterns point to MTU/MSS or fragmentation handling problems rather than DNS or basic routing.

Before applying firmware changes to any gateway, back up the current configuration, note the exact firmware build, and test after each change so you can revert cleanly if needed. If packet captures point to router behavior you cannot change, vendor support or a replacement device (or vendor-supported alternate firmware) are reasonable next steps.

Recommended Answers

All 6 Replies

Member Avatar for bentkey

Try doing a "ping cnn.com" from a command prompt. You won't be able to actually ping it, but it should return the IP address of cnn.com on the first line of results. If it doesn't, then you are having a dns problem. Try checking your dns settings on the router and on your PC.

Member Avatar for MtnBikerChk

Try doing a "ping cnn.com" from a command prompt. You won't be able to actually ping it, but it should return the IP address of cnn.com on the first line of results. If it doesn't, then you are having a dns problem. Try checking your dns settings on the router and on your PC.

it does return the ip address but the request times out....

Member Avatar for bentkey

That is really quite strange. cnn.com will never return the ping because they have their firewall set to not reply, but the fact that it returns the IP address implies that you have both DNS and connectivity to the Internet working. If they have software running on your machine that allows you to connect, that is something I haven't seen. What you might try, is with your machine connected directly, do an "ipconfig /all" command from the command prompt and see that the settings it returns are the same as what you have configured on your router. Also, from a command prompt, try doing a telnet "ipaddress returned from the ping command" 80 command and see if you get a connection. You won't get anything but a blank window if it succeeds, you'll get an error if it fails. It should look like this "telnet 80" remove the quotes and substitute the correct iP address. Is there any type of access restriction software running on that router? Like parental controls? Just a thought since you say you upgraded the firmware, maybe it's acting screwy.

Member Avatar for MtnBikerChk

That is really quite strange. cnn.com will never return the ping because they have their firewall set to not reply, but the fact that it returns the IP address implies that you have both DNS and connectivity to the Internet working. If they have software running on your machine that allows you to connect, that is something I haven't seen. What you might try, is with your machine connected directly, do an "ipconfig /all" command from the command prompt and see that the settings it returns are the same as what you have configured on your router. Also, from a command prompt, try doing a telnet "ipaddress returned from the ping command" 80 command and see if you get a connection. You won't get anything but a blank window if it succeeds, you'll get an error if it fails. It should look like this "telnet 80" remove the quotes and substitute the correct iP address. Is there any type of access restriction software running on that router? Like parental controls? Just a thought since you say you upgraded the firmware, maybe it's acting screwy.

you hit the nail on the head. I rolled back the firmware and that fixed the problem. Linksys stresses me out :)

THANKS!

Member Avatar for bentkey

Glad you got it fixed! :D Firmware updates? ...as the saying goes, "If it ain't broke....."

Member Avatar for MtnBikerChk

Glad you got it fixed! :D Firmware updates? ...as the saying goes, "If it ain't broke....."

I usually go with that motto but I was having other problems with my router so I thought the upgrade would help.

GUESS NOT! :)

Be a part of the DaniWeb community

We're a friendly, industry-focused community of developers, IT pros, digital marketers, and technology enthusiasts meeting, networking, learning, and sharing knowledge.