Example: Configuring RSVP-Signaled LSPs

Requirements

Before you begin, delete security services from the device. See Example: Deleting Security Services.

Overview and Topology

Using RSVP as a signaling protocol, you can create LSPs between routers in an IP network. In this example, you configure a sample network as shown in Figure 1.

Figure 1: Typical RSVP-Signaled LSP

To establish an LSP between routers, you must individually enable the MPLS family and configure RSVP on each of the transit interfaces in the MPLS network. This example shows how to enable MPLS and configure RSVP on the ge-0/0/0 transit interface. Additionally, you must enable the MPLS process on all of the MPLS interfaces in the network.

This example shows how to define an LSP from R1 to R7 on the ingress router (R1) using R7’s loopback address (10.0.9.7). The configuration reserves 10 Mbps of bandwidth. Additionally, the configuration disables the CSPF algorithm, ensuring that Hosts C1 and C2 use the RSVP-signaled LSP that correspond to the network IGP's shortest path.

Configuration

CLI Quick Configuration

To quickly configure this example, copy the following commands, paste them into a text file, remove any line breaks, change any details necessary to match your network configuration, and then copy and paste the commands into the CLI at the [edit] hierarchy level.

Step-by-Step Procedure

1. Enable the MPLS family on all transit interfaces in the MPLS network.
   [edit]user@host# set interfaces ge-0/0/0 unit 0 family mpls
2. Enable RSVP on each transit interface in the MPLS network.
   [edit]user @host# set protocols rsvp interface ge-0/0/0
3. Enable the MPLS process on the transit interface in the MPLS network.
   [edit]user@host# set protocols mpls interface ge-0/0/0
4. Define the LSP on the ingress router.
   [edit protocols mpls]user@host# set label-switched-path r1-r7 to 10.0.9.7
5. Reserve 10 Mbps of bandwidth on the LSP.
   [edit protocols mpls]user @host# set label-switched-path r1-r7 bandwidth 10m

Results

Confirm your configuration by entering the show command from configuration mode. If the output does not display the intended configuration, repeat the configuration instructions in this example to correct it.

For brevity, this show command output includes only the configuration that is relevant to this example. Any other configuration on the system has been replaced with ellipses (...).

If you are done configuring the device, enter commit from configuration mode.

Verification

To confirm that the configuration is working properly, perform these tasks:

• Verifying RSVP Neighbors
• Verifying RSVP Sessions
• Verifying the Presence of RSVP-Signaled LSPs

Verifying RSVP Neighbors

Purpose

Verify that each device shows the appropriate RSVP neighbors—for example, that Router R1 in Figure 1 lists both Router R3 and Router R2 as RSVP neighbors.

Action

From the CLI, enter the show rsvp neighbor command.

RSVP neighbor: 2 learned
Address            Idle Up/Dn LastChange HelloInt HelloTx/Rx 
10.0.6.2              0  3/2       13:01        3   366/349 
10.0.3.3              0  1/0       22:49        3   448/448 

The output shows the IP addresses of the neighboring routers. Verify that each neighboring RSVP router loopback address is listed.

Verifying RSVP Sessions

Purpose

Verify that an RSVP session has been established between all RSVP neighbors. Also, verify that the bandwidth reservation value is active.

Action

From the CLI, enter the show rsvp session detail command.

Ingress RSVP: 1 sessions

10.0.9.7
  From: 10.0.6.1, LSPstate: Up, ActiveRoute: 0
  LSPname: r1–r7, LSPpath: Primary
  Bidirectional, Upstream label in: –, Upstream label out: -
  Suggested label received: -, Suggested label sent: –
  Recovery label received: -, Recovery label sent: 100000
  Resv style: 1 FF, Label in: -, Label out: 100000
  Time left:    -,  Since: Thu Jan 26 17:57:45 2002
  Tspec: rate 10Mbps size 10Mbps peak Infbps m 20 M 1500
  Port number: sender 3 receiver 17 protocol 0
  PATH rcvfrom: localclient
  PATH sentto: 10.0.4.13 (ge-0/0/1.0) 1467 pkts
  RESV rcvfrom: 10.0.4.13  (ge-0/0/1.0) 1467 pkts
  Record route: <self> 10.0.4.13  10.0.2.1  10.0.8.10  
 

The output shows the detailed information, including session IDs, bandwidth reservation, and next-hop addresses, for each established RSVP session. Verify the following information:

• Each RSVP neighbor address has an entry for each neighbor, listed by loopback address.
• The state for each LSP session is Up.
• For Tspec, the appropriate bandwidth value, 10Mbps, appears.

Verifying the Presence of RSVP-Signaled LSPs

Purpose

Verify that the routing table of the entry (ingress) router has a configured LSP to the loopback address of the other router. For example, verify that the inet.3 routing table of the R1 entry router in Figure 1 has a configured LSP to the loopback address of Router R7.

Action

From the CLI, enter the show route table inet.3 command.

inet.3: 2 destinations, 2 routes (2 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both

10.0.9.7/32         *[RSVP/7] 00:05:29, metric 10
                    > to 10.0.4.17 via ge-0/0/0.0, label-switched-path r1–r7

The output shows the RSVP routes that exist in the inet.3 routing table. Verify that an RSVP-signaled LSP is associated with the loopback address of the exit (egress) router, R7, in the MPLS network.