Verifying an MPLS Configuration

The tasks required to verify your MPLS configuration depend on the signaling protocol used. To validate the configuration, perform the appropriate set of tasks:

• Verifying an LDP-Signaled LSP
• Verifying an RSVP-Signaled LSP

Verifying an LDP-Signaled LSP

Suppose that LDP is configured to establish an LSP as shown in Figure 79.

To verify the LDP configuration, perform these verification tasks:

• Verifying LDP Neighbors
• Verifying LDP Sessions
• Verifying the Presence of LDP-Signaled LSPs
• Verifying Traffic Forwarding over the LDP-Signaled LSP

Verifying LDP Neighbors

Purpose

Verify that each router shows the appropriate LDP neighbors—for example, that Router R5 has both Router R6 and Router R7 as LDP neighbors.

Action

From the CLI, enter the show ldp neighbor command.

Sample Output

Address     Interface       Label space ID      Hold time
10.0.8.5    ge-0/0/0.0      10.0.9.6:0            14
10.0.8.10   ge-0/0/1.0      10.0.9.7:0            11

Meaning

The output shows the IP addresses of the neighboring interfaces along with the interface through which the neighbor adjacency is established. Verify the following information:

• Each interface on which LDP is enabled is listed.
• Each neighboring LDP interface address is listed with the appropriate corresponding LDP interface.
• Under Label space ID, the appropriate loopback address for each neighbor appears.

Related Topics

For a complete description of show ldp neighbor output, see the Junos Routing Protocols and Policies Command Reference.

Verifying LDP Sessions

Purpose

Verify that a TCP-based LDP session has been established between all LDP neighbors. Also, verify that the modified keepalive value is active.

Action

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

Sample Output

Address: 10.0.9.7, State: Operational, Connection: Open, Hold time: 28
  Session ID: 10.0.3.5:0--10.0.9.7:0
  Next keepalive in 3 seconds
  Passive, Maximum PDU: 4096, Hold time: 30, Neighbor count: 1
  Keepalive interval: 10, Connect retry interval: 1
  Local - Restart: disabled, Helper mode: enabled
  Remote - Restart: disabled, Helper mode: disabled
  Local maximum recovery time: 240000 msec
  Next-hop addresses received:
    10.0.8.10
    10.0.2.17

Meaning

The output shows the detailed information, including session IDs, keepalive interval, and next-hop addresses, for each established LDP session. Verify the following information:

• Each LDP neighbor address has an entry, listed by loopback address.
• The state for each session is Operational, and the connection for each session is Open. A state of Nonexistent or a connection of Closed indicates a problem with one of the following:
  • LDP configuration
  • Passage of traffic between the two devices
  • Physical link between the two routers
• For Keepalive interval, the appropriate value, 10, appears.

Related Topics

For a complete description of show ldp session detail output, see the Junos Routing Protocols and Policies Command Reference.

Verifying the Presence of LDP-Signaled LSPs

Purpose

Verify that each Juniper Networks device's inet.3 routing table has an LSP for the loopback address on each of the other routers.

Action

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

Sample Output

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

10.0.9.6/32         *[LDP/9/0] 00:05:29, metric 1
                    > to 10.0.8.5 via ge-0/0/0.0
10.0.9.7/32         *[LDP/9/0] 00:05:37, metric 1
                    > to 10.0.8.10 via ge-0/0/1.0

Meaning

The output shows the LDP routes that exist in the inet.3 routing table. Verify that an LDP-signaled LSP is associated with the loopback addresses of the other routers in the MPLS network.

Related Topics

For a complete description of show route table output, see the Junos Routing Protocols and Policies Command Reference.

Verifying Traffic Forwarding over the LDP-Signaled LSP

Purpose

Verify that traffic between Hosts C1 and C2 is forwarded over the LDP-signaled LSP between Router R6 and Router R7. Because traffic uses any configured gateway address by default, you must explicitly specify that the gateway address is to be bypassed.

Action

If Host C1 is a Juniper Networks router, from the CLI enter the traceroute 220.220.0.0 source 200.200.0.1 bypass-routing gateway 172.16.0.1 command.

Sample Output

traceroute to 220.220.0.1 (172.16.0.1) from 200.200.0.1, 30 hops max, 40 byte packets
 1  172.16.0.1 (172.16.0.1)  0.661 ms  0.538 ms  0.449 ms
 2  10.0.8.9 (10.0.8.9)  0.511 ms  0.479 ms  0.468 ms
    MPLS Label=100004 CoS=0 TTL=1 S=1
 3  10.0.8.5 (10.0.8.5)  0.476 ms  0.512 ms  0.441 ms
 4  220.220.0.1 (220.220.0.1)  0.436 ms  0.420 ms  0.416 ms

Meaning

The output shows the route that traffic travels between Hosts C1 and C2, without using the default gateway. Verify that traffic sent from C1 to C2 travels through Router R7. The 10.0.8.9 address is the interface address for Router R5.

Related Topics

For information about the traceroute command and its output. see the Junos System Basics and Services Command Reference.

Verifying an RSVP-Signaled LSP

Suppose that RSVP is configured to establish an LSP as shown in Figure 80.

To verify the RSVP configuration, perform these verification 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 lists both Router R3 and Router R2 as RSVP neighbors.

Action

From the CLI, enter the show rsvp neighbor command.

Sample Output

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 

Meaning

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

Related Topics

For a complete description of show rsvp neighbor output, see the Junos Routing Protocols and Policies Command Reference.

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.

Sample Output

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  
 

Meaning

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.
• Under Tspec, the appropriate bandwidth value, 10Mbps, appears.

Related Topics

For a complete description of show rsvp session detail output, see the Junos Routing Protocols and Policies Command Reference.

Verifying the Presence of RSVP-Signaled LSPs

Purpose

Verify that the inet.3 routing table of the entry (ingress) router, R1, has a configured LSP to the loopback address of Router R7.

Action

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

Sample Output

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

Meaning

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.

Related Topics

For a complete description of show route table output, see the Junos Routing Protocols and Policies Command Reference.