Cisco 675/678 DSL Router Configuration

Sonora Communications, Inc.

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Cisco 675/678 DSL Router Configuration

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 Router Port Label

Original Cable Color 

Connection Type

 Connected Equipment
 Mgmt  Blue
Serial  Serial Port on PC
 Enet  Yellow
 Crossover  NIC in PC
 Wall  Purple
(phone cord)
 DSL  DSL/Phone Jack on Wall
 Phone  Clear/Silver
(phone cord)
 Analog Telephone

Note: Cisco 675 has DSL filter built-in for Phone jack.  Cisco 678 does not - use an external filter on the Phone port when connecting telephone equipment.


Console (Mgmt) Port 

With the Cisco Router powered up and plugged into a Com port on the PC start a Hyperterminal session. 

  • Name: Cisco
  • Connect using: Com1 or Com2 (Blue cable)
  • Bits Per Second: 38400
  • Data bits: 8
  • Parity: None
  • Stop: 1
  • Flow Control: None
  • Click Ok 

Hit <enter>.  You should get a responce from the router.

At the Password prompt: hit <enter>.

Go into Enable Mode: 'enable' <enter>

Enter is implied at the end of each line and when a password is requested prior to a password being set.

There arre two levels of passwords: Exec and Enable.  The Enable mode allows you to change settings. 

After the password has been set the password must be entered when requested.  Also, after the password has been set, the unit can be configured with a Telnet session.

The default IP address is

HTTP (Browser) Configuration

  • User: enable
  • Password: <enable password>

Programming Example for Static IP Addreses 

All things in <brackets> must be changed per installation.

Warning: this device must be disconnected from the phone line before this configuration is installed. Once the final reboot command is given, it may be re-connected to Qwest/US West.

cbos# enable
cbos# set nvram erase
cbos# write
cbos# reboot
cbos# enable
cbos# set ppp wan0-0 login <customer-ppp-login>
cbos# set ppp wan0-0 pass <their-password>
cbos# set int eth0 address <their-address>
cbos# set int eth0 netmask <their-mask>
cbos# set snmp enabled
cbos# set syslog disabled
cbos# set syslog remote <your-syslog-server-IP>
cbos# set prompt <customer> (8 char)
cbos# set password exec <customerpassword>
cbos# set password enable <customerpassword>
cbos# set web port 77
cbos# set web disabled
cbos# set tftp disabled
cbos# write
cbos# reboot

For customers with Cisco 678 routers, there is a choice of CAP or DMT. All customers who connected prior to 1-April-2001 (including simple change of ISP), have to know whether they are CAP or DMT. The 678 can be loaded with either CAP  or DMT firmware (but you must select one). To find your firmware version, do a "show version" when logged in to the 678.

<for CAP> (older circuits)

cbos# set inter wan0-0 close
cbos# set inter wan0-0 vci 1
cbos# set inter wan0-0 vpi 1
cbos# set inter wan0-0 open

<for DMT> (newer circuits - use this if in doubt)

cbos# set inter wan0-0 close
cbos# set inter wan0-0 vpi 0
cbos# set inter wan0-0 vci 32
cbos# set inter wan0-0 open

Note: For static routers, DHCP service is generally disabled, although there is no reason why the DSL router cannot be a DHCP server. In the configuration above, DHCP is not turned on, which means that it is off by default.

DHCP Server Configuration Commands

cbos# set dhcp server pool 0 dns <dns-server-IP>
cbos# set dhcp server pool 0 sdns <second-dns-server-IP>
cbos# set dhcp server ip <base-inside-IP-address>
cbos# set dhcp server size <size-of-lease-pool>
cbos# set dhcp server wins <wins-server>
cbos# set dhcp server swins <second-wins-server>
cbos# set dhcp server enable

NAT Configuration Commands

cbos# set nat outside ip <static-IP-of-router>
cbos# set nat entry add <inside-IP-of-server> <port> <static-IP-of-router> <tcp-or-udp>
cbos# set nat entry delete <inside-IP-of-server> <port> <static-IP-of-router> <tcp-or-udp>
cbos# set nat enable
cbos# set nat disable 

Show Configuration and Status

cbos# show interface wan0

cbos# show config

Set Factory Defaults 

  • Enter RMON mode
    • Establish serial communication
    • Recycle the power to the router
    • Immediately hit <control-C> at the "Hello!" message
  • Erase the configuration and reboot
    • es 6
    • rb

Update the Firmware

  • Dowload the latest firmware
  • Log in and enable
  • Update the firmware
    • set download code
    • send .bin firmware file via xmodem protocol
Last Updated on Sunday, 06 July 2008 21:19