Cisco Frame Relay analysis and experimentation

Frame Relay is a connection-oriented two-layer packet switching technology, the core idea is to use a unique DLCI (link identifier) number to build a virtual channel to the destination, when the packet is forwarded, through the DLCI to select the path. It is a network technology that differs from the two layer Mac switching technology and the three layer IP routing technology.

Three basic terms:

PVC: Permanent virtual link, virtual link is established permanently, its performance in the carrier and its frame Relay switch configuration of the static exchange table implemented.

DLCI: The value used to uniquely identify the router and the Frame Relay switch PVC or SVC.

LMI: A signaling standard between a router and a Frame relay switch to manage the connection and connection status between devices.

Basic idea of configuration:

(Environment is Cisco GNS3, Frame Relay switch with router emulation)

SW-FR

1. Turn on Frame Relay switching function Frame-relay switching

2, enter the interface, activate. Encapsulation is Frame relay. The encapsulation Frame-relay frame type has Cisco and IETF two kinds. The default is Cisco.

3. Configure the management type of LMI, Frame-relay lmi-type Cisco, configure the interface for the DCE Frame-relay intf-type DCE for Frame relay.

4, configure the Frame Relay exchange table.

int s0/0

frame-relay Route intterface S0/1 200

int S0/1

frame-relay Route intterface s0/0 100

Route

1, enter the interface, sealing and binding relay protocol. The encapsulation Frame-relay package type needs to be the same as the peer SW interface. Configure the type of management for LMI, and align to the end. Configure the IP activation interface.

At this point, the router supports the reverse ARP protocol by default, and it dynamically maps its DLCI number to the other's IP to form a path.

We generally do the mapping of the collection.

2. Configure Frame Relay mappings. First we must turn off the reverse ARP function. (similar to the ability to configure static IP to turn off DHCP)

Manual mapping:

R1 int s0/0

Frame-relay map IP 192.168.12.1 broadcast.

R2 int S0/1

Frame-relay map IP 192.168.23.3 broadcast.

Configuration is complete. Can already enter SW view Frame Relay exchange table

Show Frame-relay Route

To view the virtual channel:

Show Frame-relay PVC

To view the mapping table:

Show Frame-relay Map

View LMI

Show Frame-relay LMI

Clean up the mapping table:

Clear Frame-relay Inary

Finally ping test, Unicom.

Cisco Frame Relay analysis and experimentation