# Network freezing (NAT/DSL)

## iluvatar

I've just finished setting up a new box to replace my old windows XP nat box... This box has everything iptables/nat releated as modules and iptables/etc seems to work fine where eth1 is connected to my dsl modem and eth0 is connected to the computer I'm writing this on via coax cable. Both internal cards are ne2k-pci-compliant while the dsl one is a 3com 3c59x-ish one.

I can surf the web, use ssh, do anything.

BUT: and this is a big but; The connection between the boxes has a tendency to freeze for up to a minute or so then come back again out of nowhere, regardless of what I'm doing - be it surfing the web or ssh'ing or quake3'ing...

does anyone have an idea as to what is causing this problem?

here's an example ping (-i 5) run I had from this box to the gateway one

```
64 octets from 192.168.0.1: icmp_seq=45 ttl=255 time=0.5 ms

64 octets from 192.168.0.1: icmp_seq=46 ttl=255 time=0.5 ms

64 octets from 192.168.0.1: icmp_seq=47 ttl=255 time=0.4 ms

64 octets from 192.168.0.1: icmp_seq=66 ttl=255 time=68.5 ms

64 octets from 192.168.0.1: icmp_seq=67 ttl=255 time=0.7 ms

64 octets from 192.168.0.1: icmp_seq=77 ttl=255 time=1159.0 ms

wrong data byte #0 should be 0xbc but was 0xbbbb 61 1a 3d 88 97 b 0 

   8 9 a b c d e f 10 11 12 13 14 15 16 17 18 19 1a 1b 1c 1d 1e 1f 20 21 22 23 24 25 26 27 

   28 29 2a 2b 2c 2d 2e 2f 

64 octets from 192.168.0.1: icmp_seq=78 ttl=255 time=159.2 ms

64 octets from 192.168.0.1: icmp_seq=79 ttl=255 time=0.5 ms

64 octets from 192.168.0.1: icmp_seq=80 ttl=255 time=0.5 ms

```

A freezeup obviously occured while the ping was a farking whole second... if I run the ping for an extensive period I get around 40% packetloss, something I find quite scary...

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## iluvatar

Could the mtu setting on the different cards have anything to do with it?

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## klieber

Are the MTU settings on the cards different?

--kurt

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## iluvatar

eth1 gateway = 1500

ppp0 gateway = 1492

eth0 gateway = 1452

eth0 desktop = 1452

Should all those be the same?

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## iluvatar

n/m ...

I can't seem to figure out why... I've tried every possible mtu configurations and tested all nics and cable for errors and come up with nothing...

I'm going back to winXP as my gateway until I can figure out how to set up a _proper_ fully working linux-only network....

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