I got my wife an iPad 2 for Christmas and she soon started complaining about the Wifi dropping its connection. I suggested she try turning off the “auto join” wifi setting, but that didn’t help. She’d be doing something and get the “Sorry, there’s no internet connection” error every 5-10 minutes. We’ve had FiOS for quite a while and we have 8 or 9 other devices connected (including Macs & iPhones) to the router without issue, so this seemed weird. I was starting to think it was a problem with the iPad, but we went to a friend’s house and used his wifi (with a Netgear router) and the iPad had no issues.

Back home, I logged into the router and tried assigning her iPad a static IP through DHCP. I had her release and renew and she got the new IP but the problem continued. Since we ruled out a problem with the iPad and I knew there was nothing “wrong” with the router, I figured I’d check and see if there are any reported issues with iPads and the Verizon router. Sure enough, there are. The first thing I clicked on, Fix for Verizon FIOS vs. iPad Wi-Fi Issues, suggested changing the wifi channel from “Automatic” to “6″ (it also suggests switching from WEP to WPA2-PSK, which I’ve always been using). I did that and it hasn’t dropped the wifi connection at all in the past 3 hours. Very odd issue. If I could get into the Actiontec (or the iPad for that matter) I’d like to check the logs and see what’s actually happening, but a win’s a win.

This is what I use on my CentOS boxes/VMs, it rate-limits the connections and also rate-limits the log messages (to prevent attacks that attempt to fill up the server’s disk).

iptables -F
iptables -X
iptables -N LOGDROP #Create the LOGDROP chain
iptables -A LOGDROP -m limit --limit 1/s -j LOG --log-prefix "LOGDROP: " # Rate-limit the logging so the logs don't fill up the server
iptables -A LOGDROP -j DROP
iptables -I INPUT -p tcp --dport 22 -s 10.0.0.0/16 -j ACCEPT # Allow everything from the internal network
iptables -I INPUT -p tcp --dport 22 -i eth0 -m state --state NEW -m recent --set # create the "bucket"
iptables -I INPUT -p tcp --dport 22 -i eth0 -m state --state NEW -m recent --update --seconds 60 --hitcount 4 -j LOGDROP # if there are more than 4 connection attempts in 60 seconds from a given address, log-drop it.


After issuing these commands I run /etc/init.d/iptables save, that persists the rules to … somewhere. Alternatively I sometimes put all the above commands in some bash script and just call it from /etc/rc.local.