CCNA Lab Topology?

[roadkill01]

Hi guys,

i found this picture of a basic ccna lab topology: my question is in the picture there are 2 serial cables coming from both routers (SO - S1) my ccna lecturer seems to think this is not necessary to have the 2 serial ports configured, but iam thinking i could configure one serial port to use PPP and the other with HDLC, And different routeing protocols?

Would this work.

[Joseph W. Doherty]

Not 100% certain about the back to back connections supporting either PPP and HDLC but believe they can.

With different interfaces, you should be able to use them with different protocols. Depending on the protocol, you can sometimes run different process instances of it. If VRF is supported on your routers, you can also run multiple instances of the same protocol.

Running multiple, or instances of, protocols on the same router allows you to work with some of the most "interesting" routing considerations.