Tuesday 26 November 2019

PPP Encapsulation, CHAP and PAP

Note: HDLC is the default serial encapsulation. Both ends of serial link must be configured the same.


Configure PPP Encapsulation for Serial 0 at both R1 and R2

R1 (config) # int s0/0/0
R1 (config-if) # encapsulation ppp / encap ppp

Note: If OSPF was already configured, the link will go down, until the other end has also been configured as PPP and the link should go up.

R2 (config) # int s0/0/0
R2 (config-if) # encapsulation ppp / encap ppp

R1 (config) # do show int s0/0/0


Configure PPP (with CHAP or PAP Authentication) at Serial 0 for both R1 and R2
Hostname = username
password = cisco

R1 (config) # username R2 password cisco (or secret class)
R1 (config) # int s0/0/0
R1 (config-if) # encapsulation ppp / encap ppp
R1 (config-if) # ppp authentication chap / ppp auth chap (or pap)

If secret class is used,
R1 (config-if) # ppp chap (or pap) sent-username R1 password cisco

Note: If OSPF was already configured, the link will go down, until the other end has also been configured as PPP and the link should go up.

R2 (config) # username R1 password cisco (or secret class)
R2 (config) # int s0/0/0
R2 (config-if) # encapsulation ppp / encap ppp
R2 (config-if) # ppp authentication chap / ppp auth chap (or pap)

If secret class is used,
R1 (config-if) # ppp chap (or pap) sent-username R1 password cisco

R1 (config) # do show int s0/0/0