Cisco 1721 NAT Problem - Only Even last octets work. 1

[Saugilsr]

I have a very strange problem.
I have just installed a new core 3550 switch connected to a new 1721 router. The 3550 is setup with vlans to 2950 switches. Everything within the interal network works fine, including intervlan routing.
However, when trying to access the internet devices that have an EVEN last octet number can access the external gateway those with ODD number IPs cant. This is not only for computers but switches aswell!
The switches are all on VLAN 10 with ips of 10.0.10.x.
A switch with an ip of 10.0.10.2 can access the external gateway a switch with 10.0.10.3 can't. The same holds true for all the desktops. Very strange.
If anyone has run into this before I'd really appreciate some help. The NAT seems fairly straight forward.

Router Config:
version 12.3
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname cisco1721
!
boot-start-marker
boot-end-marker
!
!
mmi polling-interval 60
no mmi auto-configure
no mmi pvc
mmi snmp-timeout 180
no aaa new-model
ip subnet-zero
ip cef
!
!
!
no ip domain lookup
ip name-server x.x.175.133
ip name-server x.x.140.194
no ftp-server write-enable
!
!
!
!
interface Ethernet0
ip address x.x.159.106 255.255.255.248
ip nat outside
half-duplex
!
interface Ethernet1
no ip address
shutdown
half-duplex
!
interface FastEthernet0
ip address 10.0.0.1 255.255.255.0
ip nat inside
speed auto
!
ip nat inside source list 7 interface Ethernet0 overload
ip classless
ip route 0.0.0.0 0.0.0.0 x.x.159.105
ip route 10.0.0.0 255.0.0.0 10.0.0.2
no ip http server
!
access-list 7 permit 10.0.0.0 0.0.0.254
access-list 7 permit 10.0.2.0 0.0.0.254
access-list 7 permit 10.0.10.0 0.0.0.254
access-list 7 permit 10.0.20.0 0.0.0.254
access-list 7 permit 10.0.30.0 0.0.0.254
access-list 7 permit 10.0.40.0 0.0.0.254
access-list 7 permit 10.0.50.0 0.0.0.254
access-list 7 permit 10.0.60.0 0.0.0.254
access-list 7 permit 10.0.70.0 0.0.0.254
!
line con 0
line aux 0
line vty 0 4
login
!
!
end

 

[Lundah]

The problem is in your access list statements. Change the wildcard masks to 0.0.0.255 and give it a shot. By using 0.0.0.254, you're telling the router to deny anything with a 1 for the LSB in the IP address (any odd number).

 

[Saugilsr]

Wow thanks Lundah, I was following:

http://www.cisco.com/warp/public/556/12.html

Which made it appear that you gave it a Range rather then a mask. So I was trying to give it a range 0-254. But once I made the change it all came up great!
Thanks again.