Version 6.8  417  Mediant 2600 E-SBC 
User's Manual   26. HA Maintenance 
26  HA Maintenance 
This section describes HA maintenance procedures. 
 
26.1  Maintenance of Redundant Device 
The only interface that is operational on the redundant device is the Maintenance interface. 
For maintenance, there are several protocols available for this interface (unlike the active 
device which uses the logical OAMP / management interface for these protocols): 
  Syslog: To receive Syslog messages from the redundant device, ensure that there is 
a valid VLAN and route configured from the maintenance network to where the Syslog 
server is located on the network. 
  Telnet: A Telnet server is always available on the redundant device (even if disabled 
by configuration). 
 
26.2  Replacing a Failed Device 
If you need to replace a non-functional device with a new one, the new device must be 
configured exactly as the second device, as described in ''Configuring the HA Devices'' on 
page 408. 
 
26.3  Forcing a Switchover 
If required, you can force a switchover between active and redundant devices. For more 
information, see ''High Availability Maintenance'' on page 425. 
 
26.4  Software Upgrade 
The following types of software upgrades are available on the HA system: 
  Software Upgrade with Device Reset: Both active and redundant devices burn and 
reboot with the new software version. This method is quick and simple, but it disrupts 
traffic (i.e., traffic affecting). 
  Hitless Software Upgrade: This method maintains service (i.e., not traffic affecting) 
and is as follows: 
a.  The redundant device burns and resets with the new software version. 
b.  A switchover is done between the active and redundant devices, whereby the 
redundant device becomes the active one. 
c.  The previously active device burns and resets with the new software version. 
d.  The previously active device switches over to become the active device. 
For more information on upgrading the software, see ''Software Upgrade Wizard'' on page 
444.