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I have a CentOS System with two NICs on it. One is Ethernet the other is Wireless.

The Ethernet has an address of 192.168.1.110 and is tied to a LAN. (The LAN provides DHCP and DNS for its domain of 192.168.1.*)

The Wireless card should have an address of 131.238.. and is tied to the WAN.

For some evil reason, I can get the WAN to work for a short amount of time then it suddenly dies. I have to turn on/off the connection to get it to work again.

Any suggestions?

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Sounds like a WLAN issue to me - are you 100% sure that the WLAN stack is stable and that your environment is reasonable WLAN friendly, are you getting good signal strength and S/N ratio? It could be lots of things but just checking that you have ruled out the physical layer first. –  Helvick Feb 15 '10 at 19:58
    
The machines work on WiFi no problem in a windows boot. –  Toymakerii Feb 15 '10 at 22:58
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2 Answers

Are you using DHCP on the WAN interface as well? If you are, do you have any firewall rules that might be dropping DHCP responses?

This is a complete stab in the dark, but I've seen it before where:-

  • interface is brought up
  • interface sends out DHCP request for IP
  • interface recieves a DHCP response
  • firewall rules are then loaded up

What happens then is when it comes to renew the lease, either the DHCP request doesn't get sent out of the interface, or the response is dropped, and eventually the interface drops its IP address. Restarting the interface will probably drop the rules and do the above, so it'll work again.

Again, it's a stab in the dark, so I may be wrong, but it's where I'd look first.

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yes, there is DHCP on the WAN however the lease would be about 24 hours correct? and it works for at most 10 minutes (10 glorious minutes) I have both the firewall and SELINUX disabled –  Toymakerii Feb 15 '10 at 18:43
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Odd :-/ On Debian-alikes, the DHCP leases are kept under /var/lib/dhcp3 - on my Ubuntu desktop here there's multiple files. If you look at whichever is the newest, you'll see options for the lease time (in seconds). It might be worth running tcpdump or wireshark on the WAN interface, and see if anything untoward is happening before it disconnects - if it is a DHCP problem, you'll see it on there. –  Andy Smith Feb 15 '10 at 18:53
    
I will check when I make it back into the office tomorrow. –  Toymakerii Feb 15 '10 at 22:59
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what is in your route table? do you happen to have two default routes maybe - one over wireless link and one over lan - learned from dhcp? if so - that would be cause of your problems - for lan just add static route to internal 192.168.x.x resources, nothing more.

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