Sunday, July 29, 2007

CCIE PPP over Frame-Relay

first I would like to start by explaining why we need it and how it is going to take our simple frame-relay to another level of connection, as we all know Frame-Relay is Layer 2 Technology design to reduce wide band use by sharing connections and grunting or not grunting link speed, today as you probably know the frame-relay has become obsolete by other technology's such like ADSL, Cable, Metro Ethernet and others.

ppp (point to point protocol) another layer 2 protocol design to give a better solution to hdlc (high level data link control) used to control and transport ip traffic in a reliable and secure way.


now people taught how do we give the old frame-relay more features without developing a new frame-relay, they said why not take the good old ppp and join them in a "holy matrimony" just kidding, but really why not take them both and enjoy both benefits one with sharing bandwidth and traffic shaping options and one with link integrity and security features.


so now I come to our scenario where you can see I have setup 2 routers, one with 1 serial dividing it to 2 sub interfaces and the other one with 2 serial joining them together to one multilink interface making them load balance packets and also secure using chap authentication.
the multilink is needed here only to enable load balancing and interleaving, you can do without but it is less efficient and way less cooler :-)

This is the show run on router 2:

!

username Rack1R1 password 0 cisco

!

!

interface Multilink1

ip address 192.168.1.2 255.255.255.0

ppp multilink

ppp multilink group 1

!

interface Serial1/0

no ip address

encapsulation frame-relay

serial restart-delay 0

no frame-relay inverse-arp

!

interface Serial1/0.203 point-to-point

frame-relay interface-dlci 203 ppp Virtual-Template1

!

interface Serial1/0.213 point-to-point

frame-relay interface-dlci 213 ppp Virtual-Template1

!

!

interface Virtual-Template1
no ip address

ppp authentication chap

ppp multilink group 1

!

that is the show run on router 1:

!
username Rack1R2 password 0 cisco
!
!
interface Multilink1
ip address 192.168.1.1 255.255.255.0
ppp multilink
ppp multilink group 1
!
interface Serial1/0
no ip address
encapsulation frame-relay
serial restart-delay 0
no frame-relay inverse-arp
!
interface Serial1/0


no ip address

encapsulation frame-relay

serial restart-delay 0

frame-relay interface-dlci 302 ppp Virtual-Template1

no frame-relay inverse-arp

!

interface Serial1/1

no ip address

encapsulation frame-relay

serial restart-delay 0

frame-relay interface-dlci 312 ppp Virtual-Template1

no frame-relay inverse-arp

!
!interface Virtual-Template1
no ip address
ppp authentication chap
ppp multilink group 1
!

Verify:

sh ppp multilink

Multilink1, bundle name is Rack1R1
.
.
.
Member links: 2 active,....
Vi1, since 07:53:31
Vi2, since 07:53:31

and good old ping:

ping 192.168.1.2

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 174.1.23.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 24/82/128 ms



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