Configure Internet access on a Cisco 891
Cisco 890 Series Integrated Services Routers are designed to deliver highly secure broadband, Metro Ethernet, wireless LAN connectivity, and business continuity for enterprise small branch offices. These fixed-configuration routers also come with powerful management tools, such as the web-based Cisco Configuration Professional, which simplifies setup and deployment. The Cisco 891 model includes an integrated V.92 analog modem interface.
This document describes the setup of the Internet Access for
- Dynamic IP assigned by ISP
- Static IP provided by the ISP
Dynamic IP assigned by ISP
configure terminal
enable secret somesecretpassword
! Configure the DHCP pool to assign addresses to internal hosts
ip dhcp pool vlan1pool
network 10.10.1.0 255.255.255.0
default-router 10.10.1.1
dns-server 4.2.2.2
! Do not assign addresses 1 to 30
ip dhcp excluded-address 10.10.1.1 10.10.1.30
! This is the LAN facing interface of the 800 router. Used as gateway for PCs
interface vlan 1
ip address 10.10.1.1 255.255.255.0
ip nat inside
no shut
! Interfaces FE0 to FE3 are Layer 2 interfaces
interface FastEthernet0
no shut
interface FastEthernet1
no shut
interface FastEthernet2
no shut
interface FastEthernet3
no shut
! This is the WAN interface getting address via DHCP from the ISP
interface FastEthernet 4
no shut
ip address dhcp
ip nat outside
! Configure NAT. All internal hosts will be nated on the WAN interface
ip nat inside source list 1 interface fastethernet4 overload
access-list 1 permit 10.10.1.0 0.0.0.255
ip route 0.0.0.0 0.0.0.0 fastethernet4
line vty 0 4
password somestrongpassword
Static IP provided by the ISP
configure terminal
enable secret somesecretpassword
! Configure the DHCP pool to assign addresses to internal hosts
ip dhcp pool vlan1pool
network 10.10.1.0 255.255.255.0
default-router 10.10.1.1
dns-server 4.2.2.2
! Do not assign addresses 1 to 30
ip dhcp excluded-address 10.10.1.1 10.10.1.30
! This is the LAN facing interface of the 800 router. Used as gateway for PCs
interface vlan 1
ip address 10.10.1.1 255.255.255.0
ip nat inside
no shut
! Interfaces FE0 to FE3 are Layer 2 interfaces
interface FastEthernet0
no shut
interface FastEthernet1
no shut
interface FastEthernet2
no shut
interface FastEthernet3
no shut
! This is the WAN interface with static IP
interface FastEthernet 4
no shut
ip address 100.100.100.1 255.255.255.0
ip nat outside
ip route 0.0.0.0 0.0.0.0 100.100.100.2
! Configure NAT. All internal hosts will be nated on the WAN interface
ip nat inside source list 1 interface fastethernet4 overload
access-list 1 permit 10.10.1.0 0.0.0.255
ip route 0.0.0.0 0.0.0.0 fastethernet4
line vty 0 4
password somestrongpassword