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-   -   linux home router reboot itself when NAT'ing for large number of connections (

asimov 02-29-2008 04:17 AM

linux home router reboot itself when NAT'ing for large number of connections
When trying to connect to large number of bittorrent peers for my laptop on the LAN, the router instantly reboots itself. when limiting the number of connections to 50, it doesn't reboot.

My specs are: Debian stable on an old Pentium-2 200MHz PC, 192mb RAM, one 100mbit ethernet pci card (connected to the broadband modem) and one 10mbit ethernet isa card (connected to a hub). the isa card is configured to assign ip address to all clients connected to hub using dhcp server.

I've tested the RAM using memtest, tried different ethernet card (both pci and isa), tried even to connect them to different slots on the motherboard. It just keep rebooting itself.

The logs not showing anything, and `top` shows normal load on the server.

Can someone please give me some directions?

ARC1450 02-29-2008 05:29 AM

Well, what's the memory usage when you allow as many connections as possible?

Keep in mind, routing doesn't require massive amount of processor power per se, but memory. I'd give that a check and see how far it spikes.

asimov 02-29-2008 06:32 AM

both the memory consumption and cpu usage are normal: when trying to increase the amount of open ed connections, the output of `watch -n 0.5 free -m` and `top` are constant over time :(

total memory usage is only 20MB.

ARC1450 02-29-2008 06:44 AM

Is this when people are actually trying to connect, or just when you increase the amount of maximum connections? Sorry, i should have specified before.

You could always create a cron job that writes the free memory and processor usage to a file every minute or so, and see how much it spike when it dies.

asimov 02-29-2008 08:26 AM

didn't work. the memory and cpu usage stays stable while increasing the number of connections. when i get to about 200 connections, is reboots itself :(

ARC1450 02-29-2008 08:49 AM

Wait; it reboots itself while idle and there's no connections being made?

asimov 02-29-2008 08:59 AM

no. when bittorrent is configured to allow <50 connections, while browsing or downloading from ftp at max speed, it runs fine. it only crushes when i increase the number of maximum allowed connections.

(thanks for trying to help)

asimov 03-01-2008 08:08 AM

disabling ipv6 solve the problem. I suspect the kernel tcp queue got filled when ipv4 and ipv6 were enabled simultaneously (cat /proc/net/tcp).

I hope people will find this post helpfull :)

ARC1450 03-01-2008 09:22 AM

Thanks for posting up how you fixed it. That will be most hopeful to others. :)

Sorry I couldn't have been more of a help.

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