NAT on the ISR 886VA via FastEthernet

[Exonix]

Hello,

We use ISR 886VA as Internet Router via VDSL.
Now we need to switch this router to use FastEthernet as WAN port. Here is the current configuration:

interface Ethernet0
 description WAN
 no ip address
 ip nbar protocol-discovery ipv4
 service-policy input Hosts
!
interface Ethernet0.7
 description VDSL VLAN 7 tagged
 encapsulation dot1Q 7
 pppoe enable group global
 pppoe-client dial-pool-number 1
!
interface FastEthernet0
 description LAN Trunk
 switchport mode trunk
 no ip address
!
interface FastEthernet1
 description WAN
 switchport access vlan 4
 no ip address
!
interface Vlan1
 description LAN
 ip address 10.254.1.1 255.255.255.0
 ip mtu 1492
 ip nbar protocol-discovery ipv4
 ip flow ingress
 ip nat inside
 ip virtual-reassembly in max-reassemblies 64
!
interface Vlan2
 description Guest WiFi
 ip address 10.254.2.1 255.255.255.0
 ip access-group 104 in
 ip helper-address 10.254.1.8
 ip nbar protocol-discovery ipv4
 ip flow ingress
 ip nat inside
 ip virtual-reassembly in
!
interface Vlan4
 description WAN
 ip address 192.168.102.254 255.255.255.0
 ip flow ingress
 ip nat outside
 ip virtual-reassembly in
!
interface Dialer0
 description VDSL TELEKOM
 ip ddns update hostname XXXXXXX.dyndns.org
 ip ddns update dyndns
 ip address negotiated
 no ip redirects
 no ip unreachables
 no ip proxy-arp
 ip mtu 1492
 ip nbar protocol-discovery ipv4
 ip nat outside
 ip virtual-reassembly in
 encapsulation ppp
 ip tcp adjust-mss 1452
 load-interval 30
 dialer pool 1
 dialer-group 1
 no keepalive
 ppp authentication pap callin
 ppp pap sent-username **********@********* password 7 ************
 ppp ipcp dns request
 ppp ipcp mask request
 ppp ipcp route default
 no cdp enable
!
ip nat translation tcp-timeout 14400
ip nat inside source list 101 interface Dialer0 overload
!
access-list 22 permit 10.254.1.0 0.0.0.255
access-list 101 deny   ip 10.254.1.0 0.0.0.255 10.253.3.0 0.0.0.255
access-list 101 deny   ip 10.254.1.0 0.0.0.255 10.255.10.0 0.0.0.255
access-list 101 permit ip 10.254.1.0 0.0.0.255 any
access-list 101 permit ip 10.254.2.0 0.0.0.255 any
access-list 104 permit udp host 10.254.1.8 eq bootps 10.254.2.0 0.0.0.255 eq bootps
access-list 104 permit udp host 10.254.1.8 eq bootpc 10.254.2.0 0.0.0.255 eq bootpc
access-list 104 deny   ip 10.254.2.0 0.0.0.255 10.254.1.0 0.0.0.255

I have tried to change:
ip nat inside source list 101 interface Dialer0 overload
to:
ip nat inside source list 101 interface FastEthernet1 overload
and add:

ip route 0.0.0.0 0.0.0.0 192.168.102.1

But it didn't help. What should I do to have NAT via FastEthernet1? 

Thank you in advance!

[Georg Pauwen]

Hello,

the default route needs to be:

ip route 0.0.0.0 0.0.0.0 Dialer0

[Karsten Iwen · Accepted solution]

Have you also removed the old config pointing to dialer0? That also has to be done to make it work. And the NAT-command has to use the IP-interface:

ip nat inside source list 101 interface Vlan4 overload

[Exonix]

yeah, that's what I did and it works now. Also, I had to disable Dialer 0 Interface at all.