Tag Archives: nat

Cisco 1841 + HWIC-4ESW + NAT

Cisco 1841 ethernet port + dialer interface

interface FastEthernet0/0
description == WAN interface
no ip address
duplex auto
speed auto
pppoe enable group global
pppoe-client dial-pool-number 1
no cdp enable
!
interface FastEthernet0/1
description == LAN interface
ip address 192.168.1.1 255.255.255.0
ip nat inside
ip virtual-reassembly in
ip tcp adjust-mss 1452
duplex auto
speed auto
!

interface Dialer1
description == pppoe to ISP
ip address negotiated
ip mask-reply
ip directed-broadcast
ip mtu 1492
ip nat outside
ip virtual-reassembly in
encapsulation ppp
dialer pool 1
dialer-group 1
ppp authentication chap pap callin
ppp chap hostname username@domain.tld
ppp chap password 7 060B162A5D4C222C1F
ppp pap sent-username username@domain.tld password 7 030E3100150D592954
ppp ipcp dns request
ppp ipcp route default
ppp ipcp address accept
no cdp enable
!

DHCP POOL

ip dhcp pool LAN
network 192.168.2.0 255.255.255.0
default-router 192.168.1.1
dns-server 8.8.8.8 4.4.4.4
domain-name your-domain.tld

VLAN configuration

interface Vlan2
description == LAN
ip address 192.168.2.1 255.255.255.0
ip helper-address 192.168.1.1
ip nat inside <— important part in NAT translation
ip virtual-reassembly in

HWIC-4ESW ethernet port configuration

interface FastEthernet0/0/0
description == PC LAN
switchport access vlan 2
no ip address
!
interface FastEthernet0/0/1
description == AP LAN
switchport access vlan 2
no ip address
!

NAT

ip nat inside source list 1 interface Dialer1 overload

NAT ACL

access-list 1 permit 192.168.1.0 0.0.0.255
access-list 1 permit 192.168.2.0 0.0.0.255