Facebook users: can you log in?

At this point they have backtracked to the old TOS, but only to buy them time to work out the details on another new one. There will be another attempt at change in the future.

Tom

 

We can log in on a different computer on another network using a different ISP. This means the accounts are active. Now the question is why it doesn't work at home. Since we have several computers running multiple browsers and OSes, it leaves just a few possibilities:

1) A firewall or the like is blocking access.

2) We are being blocked by IP adderss.

3) Charter.

I'll try to look at it this afternoon.

Tom

 

I have it fixed. It was a strange one, which I still find mystifying. My NAT router was lousing up the connection in some manner that I can't explain. I bypassed local DNS and firewalls, I even put my computer in the DMZ logically outside of the router, but it still didn't work. When I bypassed the router and connected directly to the cable modem facebook worked okay.

As far as I know, facebook is a simple port 80 application, so no special ports are needed. Beside that, it *did* work before, and I hadn't changed any configuration settings.

Once I knew that it was a router problem, and finding reconfiguration ineffective, I decided to update the firmware on the router. It's an old Linksys router, so I went with Tomato to get more professional features. I firmly expected the problem to be fixed with the new firmware. It wasn't.

The odd thing is that other web sites worked just fine. Only facebook had problems, at least of the sites I routinely visit.

I have a second identical router that is used as an AP and router, but not a NAT router. I swapped this one for the bad one and everything worked! I flashed the working router with Tomato and configured it exactly the same as the failed router and facebook still worked. In the end I used the "bad" router as the AP and router and kept the good router as the NAT gateway. Everyting is working fine now.

Here is what bothers me: I still don't see how a router problem kept facebook from working when other sites worked fine. I can't imagine what sort of a hardware issue could do that. I'll puzzle over it for a bit, and then drink more beer.

Tom

 

Well, darn it, I'm not completely out of the woods. After I finished all of the router work, I settled in for a quick game of OpenArena before I went to bed. Guess what, I couldn't connect to the Internet servers. Something has messed up my OpenArena connection. A quick look at the router configuration didn't show any port problems, but obviously something isn't working, so I am off for round two today.

If I don't see anything obvious, I may try DD-WRT instead of Tomato.

Tom

 

I certainly hope not. Once in a while the black clouds of a technology storm move in, but I usually work just the opposite of a Malfunction Magnet.

I have identified the problem as being specific with one computer (my main Linux box), and so far the only affected program is Open Arena connecting to a network server, either local or on the Internet. This isn't exactly a critical problem, but I can't stand it when something doesn't work. It used to work, and I want to know why it doesn't now. I worry that it's a sign of an underlying problem.

A quick sniff of network packets shows that the Quake3 user datagrams from my computer have bad checksums. Why would that be the case? I'm really puzzled.

Tom

 

The router and facebook are working fine. It's looking like the problem with OpenArena is an application problem. I guess that shouldn't surprise me, since their releases have been pretty bad recently. A little more testing and I will know for sure.

Tom

 

facebook is working fine for me since I swapped my router. As for the UDPs, you are correct. I didn't look before, so who knows. It's a data point completely out of context.

I don't really care much about running OpenArena, but it's having it inexplicably stop working that bugs me. Now I want to know why. I don't know why I can't ignore these things, but they really bug me. I will probably do some more network sniffing tomorrow. I have several other machines where it still works, so I will use them for referrence.

Tom

 

Yes, there have been a lot of updates. My other ubuntu boxes are at the same level, but the hardware and configurations are not identical.

I did a little more work with the network sniffer and protocol analyzer today. The UDP checksum issue was a red herring. My main computer has a better NIC which does checksum calculation in hardware, so the analyzer never sees the real checksum and reports it as an error. This is often called "checksum offload".

I compared the network traffic with a machine properly running OpenArena and my trouble machine. Everything works okay to a point (more on that in just a bit): my local machine (the client) does a DNS request to resolve the master server, queries the master server for a server list, and queries each server for its status. Then I select a server from the list and ask to join the game. So far everything is the same on both machines and all the network traffic is kosher.

On the working computer, the client contacts the sever and asks to be connected (this is a two step process, involving a little back and forth traffic). After the server and client connect, game status information is passed back and forth, which continues for the duration of the game.

With the broken system, everything connects okay as above, and about two exchanges are made with game status, and then my computer stops listening. The server makes a couple more tries to talk to the open port, and my computer replies each time that the port is unreachable, and then the server gives up (wisely).

Looking at the OpenArena screen on my computer, it just sits there waiting for the game state. It doesn't progress, but it does respond to <ESC> and goes back to the main OpenArena menu.

Obviously something is broken with my OpenArena program. I suspect one of the updates is incompatible, but that's just a hunch. I tried to post a question about this on the OpenArena forum, but their registration system is broken (naturally).

I cleaned off OpenArena and did a fresh installation, but it fails in exactly the same way.

The good news is that I don't see a serious problem with my computer, and I had some fun digging through the Quake3 packets on my network. The bad news is that I can't play OpenArena on my main computer.

I will keep plugging away at it in my spare time. I am curious why it is doing what it does.

Tom

 

I was running wireshark as root on the offending computer, so outbound packets are viewed before they get to the hardware. It would be informative to look outside on the segment, but that will take a little reconfiguration on my part. I may do that eventually.

Sure. I'll try to do that sometime today.

True. I can't completely eliminate the stack with my current data, but the evidence points the other way. As I said above, I was running wireshark as root.

I'm sure that's at the core of it.

Tom