Technical Documentation

Example: Frame Relay to Fast Ethernet TCC Configuration

Figure 1: TCC Interface Switching—Frame Relay to Fast Ethernet

Image g017140.gif

In the configuration example in Figure 1, Router A uses Frame Relay to connect with Router B, while Router C connects to Router B by using Fast Ethernet. Router B acts as the Layer 2 virtual switch and transparently connects Router A to Router  C.

You must enable Frame Relay encapsulation on Router A at the physical interface level.

Router A

[edit]interfaces {so-0/1/0 {description "to Router B so-0/0/0";encapsulation frame-relay;unit 600 {point-to-point;dlci 600;family inet {address 10.1.1.1/30;}}}}

Router B acts as the virtual switch. Enable the appropriate TCC encapsulations on the corresponding interfaces. In this case, configure the encapsulation frame-relay-tcc option on the logical and physical interfaces of so-0/0/0.600. Next, add the ethernet-tcc encapsulation type to the physical interface of fe-1/0/0. To enable ARP, configure the remote MAC address or IP address of Router C’s Fast Ethernet interface with the remote statement at the [edit interfaces interface-name unit 0 family tcc] hierarchy level. To enable proxy ARP, include the proxy statement at the [edit interfaces interface-name unit 0 family tcc] hierarchy level and specify the IP address of Router A.

After configuring the correct interface encapsulations, complete your cross-connect by adding both interfaces into your MPLS configuration. Include the same interfaces in the interface-switch statement at the [edit protocols connections] hierarchy level.

Router B

[edit]interfaces {so-0/0/0 {description "to Router A so-0/1/0";dce;encapsulation frame-relay-tcc;unit 600 {point-to-point; encapsulation frame-relay-tcc;dlci 600;}}fe-1/0/0 {description "to Router C fe-0/0/0";encapsulation ethernet-tcc;unit 0 {family tcc {protocol inetremote { # Addresses associated with the Ethernet TCC neighbor Router C.mac-address cc:cc:cc:cc:cc:cc; # Or, specify Router C’s IP address here.}proxy { # Addresses associated with the other TCC neighbor—Router A.inet-address 10.1.1.1;}}}}}protocols { mpls {interface so-0/0/0.600;interface fe-1/0/0.0;}connections {interface-switch FR-to-Ether {interface so-0/0/0.600;interface fe-1/0/0.0;}}}

Ethernet encapsulation is the default for Router C. Because the Fast Ethernet connection is switched at Layer 2 to reach the Frame Relay link, it is transparent to Layer 3 addressing. As a result, you must configure the IP address for the fe-0/0/0 interface in the same address space as Router A’s so-0/1/0.600 interface.

Optionally, configure static ARP on the fe-0/0/0 interface if you omit the proxy statement on Router B. The arp statement must contain the IP address from interface so-0/1/0.600 on Router A and the MAC address of the Fast Ethernet interface on Router B.

Router C

[edit]interfacesfe-0/0/0 {description "to Router B fe-1/0/0";unit 0 {family inet {address 10.1.1.2/30 {arp 10.1.1.1 mac bb:bb:bb:bb:bb:bb; # Configure this only if you did not}        # enter a proxy statement on Router B.}}}

Verifying Your Work

To verify the operational status of your TCC connection, use the show connections command on Router B:


user@router_b> show connections
CCC and TCC connections [Link Monitoring On]
  Legend for status (St)              Legend for connection types
  UN -- uninitialized                 if-sw:  interface switching
  NP -- not present                   rmt-if: remote interface switching
  WE -- wrong encapsulation           lsp-sw: LSP switching
  DS -- disabled
  Dn -- down                          Legend for circuit types
  -> -- only outbound conn is up      intf -- interface
  <- -- only inbound  conn is up      tlsp -- transmit LSP
  Up -- operational                   rlsp -- receive LSP
Connection/Circuit                  Type    St  Time last up     # Up trans
FR-to-Ether                         if-sw   Up  Dec 30 09:57:23           1
  so-0/0/0.600                      intf    Up
  fe-1/0/0.0                        intf    Up

Published: 2010-04-15