On a LAN, player keeps disconnecting randomly

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DreamGoddessLindsey
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On a LAN, player keeps disconnecting randomly

Post by DreamGoddessLindsey »

This is a bizarre problem that started happening today.

We're both using 1.3b87, have Windows 7 64-bit, and Java 6.33. I have 8GB DDR3 RAM and she has 4GB DDR2 RAM.

We just play one-on-one games here at home over the LAN. Up until today, it was simple to just start the server on my computer and then she'd connect over the LAN. Today, however, without there having been any changes whatsoever since the last time we played, during the game she kept disconnecting. It would drop off on her end (but she would still be "online" on my end), and when she would try to connect again, it would give an error that a player with that name is already on the server. After that error, my server would just vanish from the LAN tab, even though my server was still running according to my computer. There's nothing in the FAQ that seems to apply to this specific situation since it just started today with no changes on either computer from the last time we played only a couple days ago.

Port forwarding is obviously out, and UPnP can't be enabled because I have a stupid Cisco (CRAP company) modem/router combo from Mediacom (another CRAP company) that uses "ClearAccess" (CRAP software) to manage the router with no option for UPnP (which I'm not even sure would help anyway).

When she's connected, the game runs fine. She can see what I do and v9ice versa without any trouble. She just keeps dropping off for some reason. Her internet stays on and she's still on the network, but she just gets dropped from my server for no discernible reason. I'm frustrated and it's driving me crazy!
Last edited by DreamGoddessLindsey on Fri Sep 28, 2012 10:26 pm, edited 1 time in total.

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wolph42
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Re: On a LAN, player keeps disconnecting randomly

Post by wolph42 »

I don't have the answer for you, but I think it will help if you also dump the 'gather debug info' here as well. menu-->help-->debug info of both pcs.

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aliasmask
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Re: On a LAN, player keeps disconnecting randomly

Post by aliasmask »

Would you say she drops randomly or at regular intervals, like an hour? I know some of those modem/routers can specify the lease time and I've seen some of them set at 1 hour. This will essentially turn off/on your router connection every hour and interrupt your connection. This use to drive me nuts before I figured it out playing MMOs.

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jfrazierjr
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Re: On a LAN, player keeps disconnecting randomly

Post by jfrazierjr »

DreamGoddessLindsey wrote: without there having been any changes whatsoever since the last time we played
Yea.. something changed, you just have not figured it out yet. Perhaps windows update changed your/their network card driver, perhaps you/they have a virus, perhaps you/they have some additional software running that is interfering with the connection(bitTorrent can sometimes use the same port MapTool uses as it's default port) that was not running before, perhaps your/their version of java updated in a background process, perhaps your/their OS has turned to mush, perhaps your/their hardware is failing, perhaps your router is failing.

Moral of the story is..something has most definately changed, you/they just need to figure out what. Not sure if I missed it, but is it just the two of you? or are others connected also(and not having the problem.) If just the two of you, I would connecting another computer to your network and see if both have the same issues around the same time(points to your router likely), random times(likely your machine), or not at all(it's their machine).
I save all my Campaign Files to DropBox. Not only can I access a campaign file from pretty much any OS that will run Maptool(Win,OSX, linux), but each file is versioned, so if something goes crazy wild, I can always roll back to a previous version of the same file.

Get your Dropbox 2GB via my referral link, and as a bonus, I get an extra 250 MB of space. Even if you don't don't use my link, I still enthusiastically recommend Dropbox..

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Azhrei
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Re: On a LAN, player keeps disconnecting randomly

Post by Azhrei »

aliasmask wrote:I know some of those modem/routers can specify the lease time and I've seen some of them set at 1 hour.
While this is possible it's not probable. DHCP lease times specify the maximum time that the server will provide the IP address, but the client requests an updated lease at time T/2, at time T*7/8, and at time T. So there are three attempts to renew the lease before it expires.

In any case, the client gets to keep the IP address if there's a problem communicating with the DHCP server. An address lease is used entirely to let the server know which addresses are in use or available, but there's nothing to stop a client from keeping an address beyond the lease time (except for the server giving the same address to a different computer!).
jfrazierjr wrote:
DreamGoddessLindsey wrote: without there having been any changes whatsoever since the last time we played
Yea.. something changed, you just have not figured it out yet. Perhaps windows update changed your/their network card driver,
This is the most likely cause.

It sounds to me like the network card is dropping the connection, probably due to a buggy driver or bad settings in the driver. You can try looking in the driver settings for the network card and see if there's anything strange -- a Windows update may have messed with the numbers.

As Joe says, if you have a bittorrent client running it's possible that Windows is freaking out over having a gazillion ports open and active all at once. This is causing some portion of the IP stack to overflow buffers or leak memory or something similar. If a fresh reboot fixes the problem and the fix lasts a long time, then this could be the issue. If rebooting and NOT starting the bittorrent client fixes the problem permanently, then this is definitely the problem.

I don't have any further advice regarding "user serviceable components". :( I would probably run a job between the two machines that is constantly sending/receiving data and watch to see if that connection also dies. At the same time I'd be running a packet sniffer on the machine with the problem to see if any malformed packets are arriving and messing up the IP stack. There are one or two other things I'd try, but they're too techie to get into how to use them for diagnostics in a forum post.

Start by checking the Windows Update log -- when was the last driver update? Then go from there.

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aliasmask
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Re: On a LAN, player keeps disconnecting randomly

Post by aliasmask »

Azhrei wrote:
aliasmask wrote:I know some of those modem/routers can specify the lease time and I've seen some of them set at 1 hour.
While this is possible it's not probable. DHCP lease times specify the maximum time that the server will provide the IP address, but the client requests an updated lease at time T/2, at time T*7/8, and at time T. So there are three attempts to renew the lease before it expires.
I've experience this personally and so has other people on the forums. I may have some specifics wrong as to why it resets, but changing the lease time to a longer interval did fix the problem. Use to drive me nuts playing WOW. It's the main reason why I get new internet service that I request a non-router modem.

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Azhrei
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Re: On a LAN, player keeps disconnecting randomly

Post by Azhrei »

Hm.

I suppose it's possible that Windows voluntarily releases the IP address if the lease can't be renewed. And if you're hitting the router with enough packets, maybe your machine won't be able to respond to DHCP packets and will just drop them on the floor...?

Apparently Windows gives up the lease when it can't contact any DHCP server while attempting to renew. See http://technet.microsoft.com/en-us/libr ... 58919.aspx

There is a registry fix that might work as well: https://forums.aws.amazon.com/thread.js ... eID=247387 However, the last post in that thread says that Microsoft recommends against making the change. Pick your poison, I guess. :?

And here's an interesting story that shows how multiple different things can work together with strange results: http://www.threadstates.com/articles/20 ... issue.html

Anyway, you were right that Windows drops IP addresses when the DHCP server cannot be contacted but it doesn't explain why your router isn't renewing the address (except for a firmware bug in the router).

In the real world it doesn't make any sense for the client to drop the address. If the server can't be reached then there is no server on the network so what does it hurt to let the client keep their existing address? Removing the address from the client makes the network useless for that client! Oh well. :)

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aliasmask
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Re: On a LAN, player keeps disconnecting randomly

Post by aliasmask »

I've only experience this with the comcast router, so I don't know if it's a windows thing. The other person I talked to about it also had a comcast router. I figure it was just something with their firmware to be the issue.

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Re: On a LAN, player keeps disconnecting randomly

Post by neofax »

aliasmask wrote:I've only experience this with the comcast router, so I don't know if it's a windows thing. The other person I talked to about it also had a comcast router. I figure it was just something with their firmware to be the issue.
Yes, my ComCast router does this every day, but not always at the same time everyday. Also, I get the packet problem where the DD-WRT router freaks out when too many packets are being routed or too many packets have to be resent because the check is wrong.
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DreamGoddessLindsey
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Re: On a LAN, player keeps disconnecting randomly

Post by DreamGoddessLindsey »

To update, neither of us were running torrent clients or anything (she doesn't have one installed and I only use mine to download Doctor Who each Saturday), and there haven't been Windows Update in the meantime.

Still, that said, I wondered if it had anything to do with the transformer that exploded and knocked out the power the day before. Our computers are undamaged, but they hadn't shut down properly. I restarted both computers, and now both are working fine again. Still strange. Nothing changed when I restarted the computers. It was like the computers just wanted a "fresh clean restart". I usually can figure this stuff out, but it is what it is.

UPDATE: Okay, that day it started working again after a fresh restart, but today, it worked fine for four hours without a problem, then once we came back from the store, the problem started happening again. No way to test another computer, we have the only two. It's just me and my partner gaming together. It's very confusing. Both computers have been thoroughly checked and are virus-free and undamaged. Only MapTool is affected, nothing else.

DreamGoddessLindsey
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Re: On a LAN, player keeps disconnecting randomly

Post by DreamGoddessLindsey »

A new update. Today it started dropping off again like before.

Like I said, this is totally random. It'll work one day and not the next. Her computer has been scanned, no virus at all. There's nothing wrong with either computer, that much I can say with absolute certainty.

Does it mean anything that she's being dropped off the MapTool network but not the router? Her internet and the computer network both still work, MapTool just randomly says "Disconnected From Server" and boots her for no apparent reason. I've checked everything I can think of. It's frustrating.

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metatheurgist
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Re: On a LAN, player keeps disconnecting randomly

Post by metatheurgist »

Don't think I've seen checking the Transmit Buffers being mentioned yet. Random disconnection tends to be a feature of that issue.

Lee
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Re: On a LAN, player keeps disconnecting randomly

Post by Lee »

I've been on both sides of the world and seen how people use computers (or any electronic device for that matter). My guess is that you and your partner are like most people in the western hemisphere and don't shutdown their computers completely. Aside from saving money leeched off by vampire power, there are several advantages of completely powering your electronic devices off.

One of my old jobs was working on other peoples computers and networks and I kept asking myself, "how is it that I never experience anything like this?" One of the recurring causes was the consistent standby state. I'm not saying this is causing the issue but it might be something you should try out. However, if you're already doing this, move on to suggestion # 2.

#2 Are you two communicating across Wi-fi? Hook up through ethernet and see if the problem persists.

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