Router IOS basic interface configuration commands: From global configuration mode: interface NAME (go into interface config mode) NAME: ethernet0 e0 e0/0 serial0 s0 s0/0 etc ip address IPaddress MASK (assign IP address and netmask) no shutdown (bring interface up) #optional: duplex full speed 100 description INTERFACE DESC HERE Serial interface being used as DCE end of link of back-to-back routers in a (simulated) lab needs to have clock rate specified. clock rate BPS (BPS: 56000, 1000000 etc) #show controllers s0/1/0 see the DCE and clock rate bandwidth NUM000 manipulate perceived bandwidth delay NUM0 manipulate perceived delay encapsulation frame-relay | ppp | hdlc (on a serial link) #lab env: no keepalive #allow port to be up and up even if no net attached no cdp enable (disable CDP on this interface. on by default) ip address IPaddress MASK secondary (participate in additional subnet) ip access-group aclNUM in|out (apply access list in direction) #router on a stick: subinterfaces & ISL trunking encapsulation p. 178- int INT.SUBINT (802.1Q "native" VLAN is vlan1: no subint) (config-subint)# encapsulation isl|dot1q VLAN# (config-subint)# ip addr ADDR MASK Do a "no shutdown" on the interface INT Subint and Vlan# do not have to be same. PPP on serial link: (config-if)# encapsulation ppp (config-if)# ppp authentication chap (config)# hostname MYNAME (config)# username OTHERROUTERNAME password PASSWORD debug ppp authentication show interface SERIALINT