How To Configure CUBE High Availability



CUBE HA Overview


CUBE HA can provide preservation for the following:
  • Preservation of media and signaling for active calls
  • Preservation of calls in process where media has not been established yet
  • Preservation of transcoded calls 

CUBE HA does not support the following:
  • IPv6 addressing
  • SCCP based media resources such as conference bridges, transcoders, mtp, etc.
  • SRST

High Availability is similar in configuration to HSRP. However it is specifically designed for the newest Cisco Unified Border Element routers and maintaining calls in the event of a failure of one of the routers.
Calls are maintained intact without any disruption to the call. In the following image you can see a call established with the active router of an HA Pair.


Cisco Unified Border Element High Availability


When the active router becomes unavailable the standby becomes available. A Virtual IP Address is used and all routing is transferred to the standby routers Virtual IP (this virtual IP address is the same as the active router). The media and signaling of the call then continues on the standby router as if there were no interruption.

The two CUBE routers should be the same hardware and IOS version. For example you cannot have a 3900 router with an ISR 4K router as the configuration is different. In the ISR-G2 routers HA is accomplished using Hot Standby Routing Protocol(HSRP). HSRP will not be covered at this time. In ASR 1000, ISR 4K, and CSR1000 routers this is done with the Redundancy Group Infrastructure configuration which is what we are covering here.

CUBE HA Configuration

We are going to go over each configuration and how it fits in with the overall picture. Then we will go over how to verify the configuration and test it, This configuration assumes that we have an internal and an external interface there is also an interface for the checkpointing configuration which will be explained. The following network topology is what we will be working on.

Cisco Unified Border Element High Availability



Monitoring Configuration


First, we need to monitor the status of the internal and external interfaces of vCUBE- this is Gig1 and Gig2. Monitoring the line-protocol status of the interfaces allows the redundancy application to determine when a resource has gone offline.

track 1 interface GigabitEthernet1 line-protocol
track 2 interface GigabitEthernet2 line-protocol


Redundancy Application Configuration


Next we will configure the redundancy options.

 redundancy
 application redundancy
  group 1
  name cubha
  priority 101
  timers delay 30 reload 60
  control GigabitEthernet3 protocol 1
  data GigabitEthernet3
  track 1 shutdown
  track 2 shutdown


The default priority is 100. The router with the highest priority will be the active router. If something happens to either the active router or the standby router, the priority of the router is decremented by the decrement value. This can be configured. If the priority of the active router goes below the standby router, the standby router becomes the active router in the switchover.

 Other circumstances which will cause a switchover:

·      Reload or loss of power on the active router.
·      The command “redundancy application reload group rg-number self” is issued to manually reload the active router.

Timers


timers delay 30 reload 60
Delay - The amount of time to delay RG group’s initialization and role negotiation after the interface comes up – Default 30 seconds. Range is 0-10000 seconds
Reload - The amount of time to delay RG group initialization and role-negotiation after a reload – Default 60 seconds. Range is 0-10000 seconds


Checkpointing configuration


data GigabitEthernet3
This command configures the interface used for checkpointing. “Checkpointing refers to the facility or architecture to implement stateful switchover (SSO). It provides the mechanisms to help synchronize state data between the active and standby route processors or chassis in a consistent, repeatable, and well-ordered manner.”

control GigabitEthernet3 protocol 1
This command configures the interface to exchange keepalive messages between the two routers.

track 1 shutdown
track 2 shutdown
These commands correlate to if Gig1 and Gig2 line protocol goes down - which will trigger the failover process.


Voice service voip Configuration


Let’s now turn on CUBE redundancy – I am assuming other configurations such as interface ip addressing and voice service voip configuration have been done.

voice service voip
redundancy-group 1

This command will prompt you for a reload of the router.  This can be done now or after you have configured the rest.  However, a reload must happen before the HA configuration will function correctly.


Interface Configuration


Next we will configure the internal and external interfaces of the router. We will also need to configure Gig3 which will be used for the checkpointing or keepalives between the two routers.

interface GigabitEthernet1
 redundancy rii 1
 redundancy group 1 ip 172.16.10.1 exclusive the same virtual ip address will be used
   on the second CUBE

interface GigabitEthernet2
 redundancy rii 2
 redundancy group 1 ip 10.10.10.1 exclusive the same virtual ip address will be used
   on the second CUBE


The Command “redundancy rii” (Redundant Interface Identifier) is used for generating a Virtual MAC (VMAC).
Use the same rii ID value on each interface of each CUBE router that has the same Virtual IP Address (VIP). The RG group number that was configured in the redundancy configuration is used when assigning the Virtual IP Address (VIP).
The exclusive command means that the interface that is associated with an active redundancy group exclusively owns the VIP Address and the Virtual MAC. When failover occurs, the ownership of the VIP and Virtual MAC changes. The interface associated with the now active redundancy group programs the interface's Ethernet controller to accept the packets going to the Virtual MAC.

The checkpointing interface only needs the ip address.  No other configuration is necessary.
Both CUBE routers must be connected to the same switch and be configured with an IP Address on the same subnet


interface GigabitEthernet3
 ip address 10.10.1.2 255.255.255.0
 no shut

Configuration for the Second Router


Most of the configuration on the second router will be exactly the same.  Of course, the interface ip addresses will be different. The priority in the redundancy application will be lower than the desired active router. But, the virtual IP address will always be the same. All dial-peers, voice translations, etc. will all be the same so that the all functionality will be the same upon failover.

track 1 interface GigabitEthernet1 line-protocol
track 2 interface GigabitEthernet2 line-protocol
!
redundancy
 application redundancy
  group 1
   name cubeha
   priority 100     Must be lower value than the first CUBE
   timers delay 30 reload 60
   control GigabitEthernet3 protocol 1
   data GigabitEthernet3
   track 1 shutdown
   track 2 shutdown
   !
voice service voip
 redundancy-group 1 Again, this will prompt for reload
 !
interface GigabitEthernet1
 redundancy rii 1
 redundancy group 1 ip 172.16.10.1 exclusive
 !
interface GigabitEthernet2
 redundancy rii 2
 redundancy group 1 ip 10.10.10.1 exclusive
 !


interface GigabitEthernet3
 ip address 10.10.1.1 255.255.255.0
 no shut

Save the configuration on both routers and reload. Even if you reloaded before when prompted.

Verification and Testing


Now let’s verify the configuration.

CUBE1#sh redundancy application group 1
Group ID:1
Group Name:cubeha

Administrative State: No Shutdown
Aggregate operational state : Up
My Role: ACTIVE                    Shows the role of this router which means CUBE 1 is
active
Peer Role: STANDBY              Shows the role of the second router which means CUBE 2
is in Standby
Peer Presence: Yes
Peer Comm: Yes
Peer Progression Started: Yes

RF Domain: btob-one
RF state: ACTIVE
Peer RF state: STANDBY HOT

CUBE2#sh redundancy application group 1
Group ID:1
Group Name:cubeha

Administrative State: No Shutdown
Aggregate operational state : Up
My Role: STANDBY
Peer Role: ACTIVE
Peer Presence: Yes
Peer Comm: Yes
Peer Progression Started: Yes

RF Domain: btob-one
RF state: STANDBY HOT
Peer RF state: ACTIVE

Testing the configuration

To test the HA configuration we will want to get a call going through the CUBE router. 
Then enter the following command:

vCUBE1#redundancy application reload group 1 self
This can also be done on the secondary router by putting in “peer” at the end of the command instead of “self”.

This will reload the router.  You will see that the call has transferred over to CUBE2.  You can verify this by entering “show sip call”

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