Section 7: IOS and IP Features (10 Points)

  • R2 is sited in a shared data center; make the serial link back into R1 as secure as possible at Layer 2.

Did you think about IP Security (IPsec)? Well that is Layer 3; as is any form of access-list, you should realize that PPP is Layer 2 and this protocol has the capability to run CHAP over it, which makes the serial link very secure. PPP with CHAP over a serial link is just as happy as PPP over ISDN; the configuration is exactly the same. If you have configured this correctly as in Example 1-56 and Example 1-57, you have scored 2 points. Example 1-58 shows CHAP in action over the serial link.

Example 1-56. R1 Serial Line PPP CHAP Configuration
						username disco password 0 cisco
						!
						interface Serial0/0

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