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I have a Netgear WNDR3700v2 with OpenWRT. The problem is that I created a custom boot script as explained here (http://wiki.openwrt.org/doc/techref/initscripts) and after rebooting I was not able to connect to the router.

What the custom script contained was the following:

# Start fprobe to send NetFlow reports to ntop
fprobe -ibr-lan 192.168.1.22:2055 

# Start QoS scripts (the script described here: http://www.campsmur.cat/dani_home_network.html)

# Start the openVPN server, configured according to here: http://wiki.openwrt.org/inbox/vpn.howto.

I do not recall at which priority in init.d this custom init script was executed but I did not intentionally set any high priority.

Now after booting the connection with the router is lost. However, I do know the MAC of the router (is in the label: Netgear_9b:7d:a6) and the interface to which this MAC belongs, and the IP that this router interface was supposed to have (192.168.1.1). So if I try to ping this IP from a laptop connected with Ethernet (with IP 192.168.1.230) to the router this is what happens:

No. Time        Source              Destination           Protocol Length Info
2 24.567792   192.168.1.230         192.168.1.1           ICMP     155    Echo (ping) request  id=0x10eb, seq=1/256, ttl=64
3 24.576590   Netgear_9b:7d:a6      Broadcast             ARP      60     Who has 192.168.1.230?  Tell 192.168.1.1
4 24.576625   Sony_63:75:8e         Netgear_9b:7d:a6      ARP      42     192.168.1.230 is at f0:bf:97:63:75:8e
5 25.576600   Netgear_9b:7d:a6      Broadcast             ARP      60     Who has 192.168.1.230?  Tell 192.168.1.1
6 25.576608   192.168.1.230         192.168.1.1           ICMP     155    Echo (ping) request  id=0x10eb, seq=2/512, ttl=64
...

The laptop already has the MAC of the router in its ARP table, therefore issues the PING. Then the router hears this PING, but his arp table is empty and therefore sends an ARP request to find out to which MAC the laptop's IP belongs to. Then the laptop sends a reply to this ARP request, but the router ignores it and does not send the ICMP reply! This is not only an ICMP problem, it also happens if I try to ssh or to connect via the Web portal. Therefore, I have the feeling that the problem is with the ARP process in the router.

Anyone has any idea of how to connect to the router? Would it be possible to try to access using IPv6 (since there is no arp)? but I have no experience with that. Otherwise is it possible to flash a new firmware to the router without IP connectivity?

Best Regards

Daniel

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closed as off topic by joeqwerty, EEAA, Ward, Khaled, Wesley Apr 11 '12 at 0:06

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1 Answer 1

up vote 1 down vote accepted

Just do a 30/30/30 reset to revert the router to default settings. Then you can reconfigure the router.

  1. Hold the reset button down for 30 seconds. Do not release it.

  2. Turn the router off for 30 seconds. Do not release the reset button.

  3. Turn the router on. Wait 30 seconds. Finally, release the reset button.

In a minute or so, the router should be pingable on 192.168.1.1 with all settings at defaults. The firmware will be whatever you last loaded onto the router.

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Thanks, I could access the router and flash it with a new firmware. I followed the instructions here: wiki.openwrt.org/toh/netgear/… –  Dani Camps Apr 16 '12 at 15:54

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