This is a common configuration for a 1721 with a WAN T1 serial and a LAN
FastEthernet connection.  Simple alterations could make the WAN T1 into
a Ethernet or FastEthernet as well.  ACLs minimize security risk from 
outside administration attempts.

!
!
version 12.2
service nagle
no service pad
service timestamps debug datetime msec localtime show-timezone
service timestamps log datetime msec localtime show-timezone
service password-encryption
!
hostname ppp.router.generic.com
!
logging queue-limit 100
enable secret 5 secretpassword
!
username root privilege 15 password rootpassword
username tech password 7 techpassword
ip subnet-zero
!
!
ip name-server 192.168.0.1
no ip dhcp conflict logging
ip dhcp excluded-address 10.0.0.1 10.0.0.10
!
ip dhcp pool local
   network 10.0.0.0 255.255.255.0
   domain-name generic.com
   default-router 10.0.0.1
   dns-server 192.168.0.1
   lease 0 0 30
!
no ip bootp server
!
!
interface FastEthernet0
 ip address 10.0.0.1 255.255.255.0
 ip access-group 101 out
 speed 10
 half-duplex
!
interface Serial0
 ip address 172.16.50.2 255.255.255.252
!
ip classless
ip route 0.0.0.0 0.0.0.0 172.16.50.1
no ip http server
!
!
!
logging 192.168.0.20
! This set allows 192.168.0.0/24 to reach the telnet, www and ssh ports of .20
access-list 1 permit 192.168.0.0 0.0.0.255
access-list 101 permit tcp 192.168.0.0 0.0.0.255 host 10.0.0.20 eq www
access-list 101 deny   tcp any host 10.0.0.20 eq www log
access-list 101 permit tcp 192.168.0.0 0.0.0.255 host 10.0.0.20 eq telnet
access-list 101 deny   tcp any host 10.0.0.20 eq telnet log
access-list 101 permit tcp 192.168.0.0 0.0.0.255 host 10.0.0.20 eq 22
access-list 101 deny   tcp any host 10.0.0.20 eq 22 log
access-list 101 permit ip any any
!
snmp-server community private RO
snmp-server enable traps snmp authentication linkdown linkup coldstart warmstart
snmp-server enable traps tty
snmp-server enable traps isdn call-information
snmp-server enable traps isdn layer2
snmp-server enable traps isdn chan-not-avail
snmp-server enable traps hsrp
snmp-server enable traps config
snmp-server enable traps entity
snmp-server enable traps frame-relay
snmp-server enable traps frame-relay subif
snmp-server enable traps syslog
snmp-server enable traps rtr
banner motd ^C
=============================================
 Router : ppp.router.generic.com
=============================================^C
!
line con 0
 login local
line aux 0
 access-class 1 in
 login local
line vty 0 4
 access-class 1 in
 login local
line vty 5 15
 access-class 1 in
 login local
!
no scheduler allocate
ntp clock-period 17179994
ntp server 192.168.0.7
end