serial links

[carl_townshend]

Can anyone tell the the advantages of using ppp encap on a serial link, Do I have to use this, Also could I enable a username and password , pap or chap on a serial link and how is this done !!

thanks

Carlos

[right_guy12]

Hi! Carlos,

You can configuring PPP encapsulation on your serial link.

Enter the following commands at the configure terminal.

interface

encapsulation ppp

ppp authentication

Also you can configure the username and password by giving the following commands at the configure terminal

username password

Also in the username field enter the hostname of the other router and similarly enter the hostname of this router as username on the other router.

Also remember to have password encryption service active on your router.

Please note that the username field is case-sensitive.

Hope it helps!

[carl_townshend]

Hi there, thanks for the reply, I always thought the usernames and passwords had to be the same on both sides of the link, so If you used the router hostname they would be different, I would of thought you would put say username test password test, and you would put this on both ends ? Am I correct ?

[Georg Pauwen]

Hello,

the username has to be either the one of the host itself (e.g. Router1), or that configured with the ´ppp pap sent-username´ or ´ppp chap hostname´ command. Here is an example:

Router1

!

username Router2 password 0 cisco

!

interface Serial0

ip address 192.168.1.1 255.255.255.252

encapsulation ppp

ppp authentication chap

Router2

!

username Router1 password 0 cisco

!

interface Serial0

ip address 192.168.1.1 255.255.255.252

encapsulation ppp

ppp authentication chap

In this example, the actual hostname of the router is used as the username. If you want to send a different username, this is what the configuration would look like:

Router1

!

username Router2 password 0 cisco

!

interface Serial0

ip address 192.168.1.1 255.255.255.252

encapsulation ppp

ppp authentication chap

ppp chap hostname R1

Router2

!

username R1 password 0 cisco

!

interface Serial0

ip address 192.168.1.1 255.255.255.252

encapsulation ppp

ppp authentication chap

Keep in mind that for CHAP, the passwords need to match, for PAP, they don´t. Also, when you use PAP, you always need to use the ´ppp pap sent-username´ command, regardless of wether the actual hostname is being used, or a different name. So both configuration examples above with PAP instead of CHAP would look like this:

Router1

!

username Router2 password 0 cisco

!

interface Serial0

ip address 192.168.1.1 255.255.255.252

encapsulation ppp

ppp authentication pap

ppp pap sent-username Router1 password 0 cisco

Router2

!

username Router1 password 0 cisco

!

interface Serial0

ip address 192.168.1.1 255.255.255.252

encapsulation ppp

ppp authentication pap

ppp pap sent-username Router2 password 0 cIsCo

And the second example:

Router1

!

username R2 password 0 cisco

!

interface Serial0

ip address 192.168.1.1 255.255.255.252

encapsulation ppp

ppp authentication pap

ppp pap sent-username R1 password 0 cisco

Router2

!

username R1 password 0 cisco

!

interface Serial0

ip address 192.168.1.1 255.255.255.252

encapsulation ppp

ppp authentication pap

ppp pap sent-username R2 password 0 cIsCo

Does that make sense ?

Regards,

GP