PPP Authentication

• Is it a mutual authentication or only one side is authenticating?
• Clear text or scrambled password in running config:
• username R1 password 0 test
• no service password-encryption
• VTY and Console line authentication
• aaa authentication login default line none
• none required if no password is set on console
• AAA settings
• aaa authentication ppp default group radius local-case

Serial Link Compression

PPP Predictor:
Less CPU, more memory, less efficient.
R1(config-if)# compress predictor

HDLC Stacker (LZ):
More CPU, less memory, more efficient.
R1(config-if)# compress stacker

Frame Relay FRF.9 Compression
R1(config-if)# frame-relay map ip <IP-ADDRESS> <PVC> broadcast IETF payload-compression FRF9 stac one-way-negotiation