Example: Determining Member Health Using an MX Series Virtual Chassis Heartbeat Connection with Member Routers in the Same Subnet

Step-by-Step Procedure

In addition to configuring a unique IP address for the fxp0 management interface on each Routing Engine when you first set up the Virtual Chassis, you must configure an additional management IP address, known as the master-only address, to ensure consistent access to the fxp0 management interface on the primary Routing Engine in the Virtual Chassis primary router (VC-Pp, represented by member0-re0 in this example). You then use the master-only address as the heartbeat address to establish the Virtual Chassis heartbeat connection.

Because the Virtual Chassis member routers in this example both reside in the same subnet (10.4.0.0), you can configure the same master-only address for each Routing Engine. The master-only address is active only on the management interface for the VC-Pp. During a switchover, the master-only address moves to the new Routing Engine currently functioning as the VC-Pp.

To configure the master-only fxp0 IP address for each Routing Engine:

• From the console on member 0, configure the same IP address for the fxp0 management interface on each Routing Engine.

  content_copy zoom_out_map

  {master:member0-re0}[edit]
  user@master-router# set groups member0-re0 interfaces fxp0 unit 0 family inet address 10.4.2.210/16 primary-only
  user@master-router# set groups member0-re1 interfaces fxp0 unit 0 family inet address 10.4.2.210/16 master-only
  user@master-router# set groups member1-re0 interfaces fxp0 unit 0 family inet address 10.4.2.210/16 master-only
  user@master-router# set groups member1-re1 interfaces fxp0 unit 0 family inet address 10.4.2.210/16 master-only
  

Results

From the console on the Virtual Chassis primary router, display the results of the configuration for each configuration group. For brevity, portions of the configuration unrelated to this procedure are replaced by an ellipsis (...).

For member0-re0:

{master:member0-re0}[edit]
user@master-router# show groups member0-re0
system {
    host-name master-router;
    backup-router 10.4.0.1 destination [ 172.16.0.0/12 ... 10.204.0.0/16 ];
}
interfaces {
    fxp0 {
        unit 0 {
            family inet {
                address 10.4.2.100/16;
                address 10.4.2.210/16 {
                    master-only;
                }
            }
        }
    }
}

For member0-re1:

{master:member0-re0}[edit]
user@master-router# show groups member0-re1
system {
    host-name master-router1;
    backup-router 10.4.0.1 destination [ 172.16.0.0/12 ... 10.204.0.0/16 ];
}
interfaces {
    fxp0 {
        unit 0 {
            family inet {
                address 10.4.2.101/16;
                address 10.4.2.210/16 {
                    master-only;
                }
            }
        }
    }
}

For member1-re0:

{master:member0-re0}[edit]
user@master-router# show groups member1-re0
system {
    host-name backup-router;
    backup-router 10.4.0.1 destination [ 172.16.0.0/12 ... 10.204.0.0/16 ];
}
interfaces {
    fxp0 {
        unit 0 {
            family inet {
                address 10.4.3.101/16;
                address 10.4.2.210/16 {
                    master-only;
                }
            }
        }
    }
}

For member1-re1:

{master:member0-re0}[edit]
user@master-router# show groups member1-re1
system {
    host-name backup-router1;
    backup-router 10.4.0.1 destination [ 172.16.0.0/12 ... 10.204.0.0/16 ];
}
interfaces {
    fxp0 {
        unit 0 {
            family inet {
                address 10.4.3.102/16;
                address 10.4.2.210/16 {
                    master-only;
                }
            }
        }
    }
}

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

Step-by-Step Procedure

You must configure a secure and reliable path between the primary router and backup router for the exchange of TCP/IP heartbeat packets. The heartbeat packets provide critical information about the availability and health of each member router.

The route you create for the heartbeat connection must be independent of the Virtual Chassis port links. Specifically, you must ensure that the primary Routing Engine in the Virtual Chassis backup router (VC-Bp) can make a TCP/IP connection to the master-only IP address of the primary Routing Engine in the Virtual Chassis primary router (VC-Pp).

This examples creates a global static route between the member routers to configure the heartbeat path. However, you can choose the method that best meets your needs to configure the heartbeat path for member routers in the same subnet. For example, you might use the member router’s default gateway for this purpose.

To create a static route between the primary and backup member routers:

• From the console on member 0, configure a static route between the member routers in subnet 10.4.0.0.

  content_copy zoom_out_map

  {master:member0-re0}[edit]
  user@master-router# set groups global routing-options static route 10.4.0.0/16 next-hop 10.4.0.1
  user@master-router# set groups global routing-options static route 10.4.0.0/16 retain
  user@master-router# set groups global routing-options static route 10.4.0.0/16 no-readvertise
  

Results

Display the results of the configuration. For brevity, portions of the configuration unrelated to this procedure are replaced by an ellipsis (...).

{master:member0-re0}[edit]
user@master-router# show groups global routing-options static
route 10.4.0.0/16 {
    next-hop 10.4.0.1;
    retain;
    no-readvertise;
}
...

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

Step-by-Step Procedure

To establish the heartbeat connection in a two-member MX Series Virtual Chassis, you must configure the IP address for the connection between the primary and backup member routers. To ensure consistent access to the primary Routing Engine in the Virtual Chassis primary router (VC-Pp) regardless of which Routing Engine is currently active, you set the heartbeat address to the previously configured global master-only IP address for the fxp0 management interface.

Optionally, you can also configure a nondefault value for the heartbeat timeout interval. The heartbeat timeout is the maximum time within which a Virtual Chassis member router must respond to a heartbeat packet sent by the other member router. If you do not explicitly configure the heartbeat timeout interval, the default value (2 seconds) applies.

To configure the heartbeat address and heartbeat timeout:

1. From the console on member 0, specify that you want to edit the Virtual Chassis preprovisioned configuration.

   content_copy zoom_out_map

   {master:member0-re0}[edit]
   user@master-router# edit virtual-chassis
   

2. Configure the common master-only IP address for the fxp0 management interface as the heartbeat address.

   content_copy zoom_out_map

   {master:member0-re0}[edit virtual-chassis]
   user@master-router# set heartbeat-address 10.4.2.210
   

3. (Optional) Configure a nondefault value for the heartbeat timeout interval.

   content_copy zoom_out_map

   {master:member0-re0}[edit virtual-chassis]
   user@master-router# set heartbeat-timeout 20
   

Results

Display the results of the configuration.

{master:member0-re0}[edit]
user@master-router# show virtual-chassis
preprovisioned;
traceoptions {
    file VCCP size 100m;
    flag all;
}
heartbeat-address 10.4.2.210;
heartbeat-timeout 20;
member 0 {
    role routing-engine;
    serial-number JN11026AFAFC;
}
member 1 {
    role routing-engine;
    serial-number JN112C2FCAFC;
}

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

Purpose

Verify that the heartbeat connection between the Virtual Chassis member routers is properly configured and operational.

Action

Display the state of one or both member routers when a heartbeat connection is configured.

{master:member0-re0}
user@master-router> show virtual-chassis heartbeat
member0:
--------------------------------------------------------------------------
Local        Remote          State        Time
10.4.2.210   10.4.3.101      Alive        2014-02-18 11:18:14 PST

member1:
--------------------------------------------------------------------------
Local        Remote          State        Time
10.4.3.101   10.4.2.210      Alive        2014-02-18 11:18:15 PST

Meaning

For each member router, the command output displays the IP addresses of the local and remote member routers that form the heartbeat connection. The value Alive in the State field confirms that the primary Routing Engine in the specified member router is connected and has received a heartbeat response message. The Time field specifies the date and time of the last connection state change.

Purpose

Verify use of the heartbeat connection when an adjacency disruption or split is detected in the Virtual Chassis.

Action

Display the status of the member routers in the Virtual Chassis:

{master:member0-re0}
user@master-router> show virtual-chassis status
Preprovisioned Virtual Chassis
Virtual Chassis ID: 4806.94d6.2362

                                               Mastership           Neighbor List
Member ID       Status   Serial No    Model    priority    Role      ID  Interface

0 (FPC   0- 11) Heartbt  JN11026AFAFC mx240           129  Master*    1  vcp-1/0/0
                                                                      1  vcp-1/1/0

1 (FPC  12- 23) Prsnt    JN112C2FCAFC mx240           129  Backup     0  vcp-2/0/0
                                                                      0  vcp-2/1/0

Meaning

The Status field for member ID 0 displays Heartbt, which indicates that this member router has used the heartbeat packet connection to maintain primary role roles during an adjacency disruption or split in the Virtual Chassis configuration. The Status field for member ID 1 displays Prsnt, which indicates that this member router is connected to the Virtual Chassis.

If a router is not currently connected to the Virtual Chassis, the Status field displays NotPrsnt.

Purpose

Use statistics collected by the heartbeat connection to verify the availability and health of each Virtual Chassis member router. You can also use the show virtual-chassis heartbeat detail command to determine the maximum latency and minimum latency in your network.

Action

Display and review the statistics collected by the heartbeat connection.

{master:member0-re0}
user@master-router> show virtual-chassis heartbeat detail
member0:
--------------------------------------------------------------------------
Local           Remote          State        Time
10.4.2.210      10.4.3.101      Alive        2014-02-18 11:18:14 PST

Heartbeat statistics
  Heartbeats sent: 10079
  Heartbeats received: 10079
  Heartbeats lost/missed: 0
  Last time sent: 2014-02-18 20:03:10 PST (00:00:00 ago)
  Last time received: 2014-02-18 20:03:10 PST (00:00:00 ago)
  Maximum latency (secs): 0
  Minimum latency (secs): 0

member1:
--------------------------------------------------------------------------
Local           Remote          State        Time
10.4.3.101      10.4.2.210      Alive        2014-02-18 11:18:15 PST

Heartbeat statistics
  Heartbeats sent: 10083
  Heartbeats received: 10083
  Heartbeats lost/missed: 0
  Last time sent: 2014-02-18 20:03:09 PST (00:00:01 ago)
  Last time received: 2014-02-18 20:03:09 PST (00:00:01 ago)
  Maximum latency (secs): 0
  Minimum latency (secs): 0

Meaning

In this example, the number of heartbeat request messages sent (Heartbeats sent) equals the number of heartbeat response messages received (Heartbeats received), with no heartbeat messages lost (Heartbeats lost/missed). This indicates that both member routers forming the heartbeat connection were available and operational. Any difference between Heartbeats sent and Heartbeats received appears in the Heartbeats lost/missed field.

The Maximum latency and Minimum latency fields measure the maximum and minimum number of seconds that elapse on the local router between trasnmission of a heartbeat request message and receipt of a heartbeat response message. In this example, the value 0 in the Maximum latency and Minimum latency fields indicates that there is no measurable network delay caused by this operation. You can use the Maximum latency value to determine whether you need to increase the heartbeat-timeout to a value higher than the default (2 seconds). If the maximum latency in your network is too high to accommodate a 2-second heartbeat-timeout value, increasing the heartbeat-timeout interval enables you to account for network delay when a Virtual Chassis adjacency disruption or split occurs.