Netopia 4622 interfaces:
- Outside 66.x.x.221
- Inside 66.x.x.97 /29
- Config: NAT off, DHCP on (serving only 66.80.41.98 to inside interface)

Netgear VPN Router
- Outside 66.x.x.98 /29 (DHCP client)
- Inside 192.x.x.1
- Config: NAT on, DHCP on (serving inside clients)

/29 bits subnet masks give 8 available IP addresses. Megapath ISP has used an "RNET Block" to segregate managed router network. Here's the final topology:

Netopia outside IP: 66.x.x.221
IP Block:
66.x.x.96/29
Gateway IP (LAN side of netopia):
66.x.x.97
Subnet Mask:
255.255.255.248
Useable IP's:
66.80.x.98 - Netgear Router
66.80.x.99
66.80.x.100
66.80.x.101
66.80.x.102