seem to be hitting a wall on this 851, simple /29 public subnet routed from provider nat only appears to work on this unit with defined ip only and or
direct routed ip's. example below.
10.10.10.0 255.255.255.248 network
isp 10.10.10.1 255.255.255.248
851 wan 10.10.10.2 255.255.255.248 using default route of 10.10.10.1 nat works as expected using 10.10.10.2 as the global outside however the remain block does not.
isp side add 200.200.200.100 routed to 10.10.10.1 nat works as expected using 200.200.200.100 as the global outside. tried multiple ios from 12.3-12.4 with varying results but no solution to a direct attached subnet.. is this a device limitation or am i missing somthing
interface FastEthernet4
ip address 10.10.10.2 255.255.255.248
!
ip route 0.0.0.0 0.0.0.0 10.10.10.1
!
ip nat pool public 200.200.200.100 200.200.200.101 netmask 255.255.255.0
ip nat inside source list 110 pool public overload
!
ip nat inside source static tcp 192.168.1.10 80 10.10.10.3 80 extendable ( this traffic never routes )
!
access-list 110 permit ip 192.168.1.0 0.0.0.255 any
on a side note this configuration works without issue on a 831 model router along with most other branch routers tested. i am the isp so i can obviously change the handoff on the subnet but i am curious as to why the 851 does not manage to handle it
