This iptables rules set is a more detailed rules set than 
the one that is tared into the genfw.tar.gz file.
Put this one in the /etc directory to replace the other one.
Remember to change the ip addresses at the top. This one wants the
broadcast addresses as well.
example: 66.247.95.56/29's (/29 = 255.255.255.248)
would be: 66.247.95.63 (The last address in the range).
the /29 means that the route has 29 of 32 bits set so the 
first 29 bits represent the trunk and the last 3 are valid ip
addresses (3 bits = 8 numbers 0 - 7).
The first ip address is also the trunk name and is not to be used.  
The last address is the broadcast address and is not to be used. 
The middle ones are available though one of them will be the gateway address.

Making sense of ip addresses 101.

Lets say someone told you to use 66.247.95.60 with at netmask of
255.255.255.248. What is the real range of ip addresses?
256-248=8 so there are 8 available ip addresses.
(Why 256? The valid range is 0 through 255 which is 256 choices)
8 ip addresses in binary is 000 through 111 where 000=0 and 111=7.
(Use Windows->Accessories->Calculator in scientific mode)
This means that the last 3 bits of the last number are valid ip
addresses.
60 = 3C Hex = 111100 Binary
Since we get to control the last 3 bits we have
111000 through 111111 (Note: there are only six digits showing.
In Hex there are supposed to be 8. My calculator dropped the leading 0s
just like you would in a normal number).
The Dec range of 111000 to 111111 is 56 to 63.
So 66.247.95.56 is the trunk number (The first number) and not to be used.
66.247.95.63 is the broadcast number (The last number) also not to be used.
Everything in between is fair game though one of them is the gateway.

What is this /24 or /29 notation crap I keep seeing in linux?

Most of the time, you see netmasks written as 255.255.255.0 or 
255.255.255.248 or some such setting. This tells you how much
of your ip address is used to identify you network and how much is
used for identifying computers on the network.
Each number has 256 choices, 0 though 255.
255.255.255.0 means you have 256 choices minus the trunk and broadcast
so you have 254 valid addresses.
255.255.255.248 means you have 8 choices (256-248) minus the trunk
and broadcast address leaves you with 6 actual choices.
255 in binary is 8 1s in a row (11111111). 248 is 5 1s followed by 3 0s
(11111000). our mask is 8 1s, 8 1s, 8 1s, 5 1s plus 3 0s.
8+8+8+5=29 so 255.255.255.248 = /29
8+8+8=24 so 255.255.255.0 =/24
Note: In masks the right side of a mask is 0s and the left is 1s. You aren't
allowed to mix them. You can't have 11011111.11001101.0011111.11110000.
You can have 11111111.11111111.11100000.00000000
This mask allows you to have 8192 choices or 8190 computers (255.255.224.0).
(fini)

Where did you get 8192 from?

I saw that there were 13 0s so I typed a 1 followed by 13 0s
into my calculator in Bin mode and pressed Dec mode.

How did you know to use 224.0?

11100000=224 and 00000000=0.
(Remember to group the binary numbers in sets of 8)