Configure Standby
Packeteer offers two standby functions:
- The hot standby function is designed to allow two PacketShaper
or PacketSeeker units to act as a redundant pair. If the active unit
experiences a failure, the other unit automatically assumes the active
role. In other words, hot standby allows you to have a backup unit,
ready to take over if the active unit fails. Only one unit is active
at a time, but each unit is aware of the other. Under normal circumstances,
one unit is in the active state and the other is in the passive, backup
state. Both units see all LAN traffic, but only the unit in the active
state will pass traffic. The passive unit drops the packets it would
otherwise transfer. The two units are inserted in parallel between the
LAN and the WAN router.
- The direct standby function allows two Packeteer units to work
in a redundant network topology, with each unit connected to a different
router. The two units are directly connected to each other, through
the OUTSIDE port on a LAN Expansion Module. Unlike with the hot standby
function, both units are considered active and each unit can receive
and forward traffic. When a unit directly receives traffic, it will
copy that traffic and transmit it to the other unit. The other unit
will classify the traffic, just as if it had received it directly, but
it will never forward the traffic on to the LAN. As a result, each unit
is ready at any time to take over full PacketShaper/PacketSeeker responsibility
should the other unit go down.
Note: The standby feature requires a hardware modification. For
details on this modification, as well as instructions for cabling the
units, see the Getting
Started Guide.
Identical Passwords
In order for direct and hot standby to work, both units
must be configured with the same touch password. See Specify
Security Settings for details on changing the password.
If you change the password on one of the units when direct
standby is enabled, direct standby will continue functioning, giving you
an opportunity to change the password on the other unit. However, if one
of the units is reset while the two units have different passwords, direct
standby will be disabled until the passwords are identical and both units
are reset (or until standby is turned off and then back on).
Similar Traffic Trees
When using the direct standby function, the two Packeteer
units must have similar traffic trees so that flows will be classified
and controlled identically, and the same measurement data will be collected
on each unit. You’ll want to make sure each unit has the same traffic
classes, policies, partitions, and settings. Packeteer offers several
ways you can configure units with the same settings. See Configure
Units to Have Similar Traffic Trees.
Enabling Standby
To select a standby function:
1. Click the setup tab.
2. From the Choose Setup Page list, select
standby. The Standby Configuration settings appear on the Setup
screen.  show screen
3. Select the type of standby: Hot or Direct.
4. If you selected Hot, enter the IP address
of the other unit in the Peer IP Address field. show screen
For example, suppose the two units being configured are 192.68.15.12 and
192.68.15.13. When configuring the 192.68.15.12 unit, you would specify
192.68.15.13 for the peer IP address.
Note: For direct standby, you do not need to specify the IP address
of the peer unit. (That's why the Peer IP Address field appears
only for hot standby.)
5. Click apply changes.
Note: A loss of connectivity could occur right after
direct standby is enabled or disabled. This loss of connectivity is transient
and recoverable after the new paths and routes have been established.
After the paths and routes have stabilized, you may have to start a new
browser session.
Standby Status Messages
The Standby Configuration setup page displays the status
of the current unit.
Hot Standby
Status Messages |
Description |
| Running Standby/Hot in passive mode. |
The unit is functioning as the passive hot standby unit. It is not
passing traffic, but is monitoring. It is sending keep-alive messages
to the active unit, and receiving keep-alive messages from the active
unit. |
| Running in Standby/Hot in active mode. |
The unit is functioning as the active hot standby unit. It is passing
traffic and sending keep-alive messages to the passive unit. |
| Running in Standby/Hot in down mode. |
The unit is not passing traffic because one or both of the Ethernet
interfaces has lost link state. A unit in standby down state will
signal the other unit to become, or remain, active. |
| Standby/Hot active (partner never established contact). |
The unit is functioning as the active hot standby unit, but was
never able to communicate with the other standby unit. |
| Standby/Hot active (partner down). |
The unit is functioning as the active hot standby unit, but the
passive unit is no longer sending keep-alive messages. |
| Standby/Hot active (partner failed). |
The unit is currently functioning as the active hot standby unit
because the other unit (which was previously active) has failed. |
Direct Standby
Status Messages |
Description |
| Standby/Direct is active with partner <standbyPeer>. |
The unit has successfully communicated with its direct standby partner.
If the unit directly receives traffic, it will copy that traffic and
transmit it to the partner unit. The unit will also receive forwarded
traffic from the partner; the forwarded traffic will be classified
and then dropped. |
| Standby/Direct has not found a partner. |
The unit is unable to establish communication with another Packeteer
unit. Make sure the units are directly cabled though the OUTSIDE port
on the uppermost LEM. |
| Standby/Direct disabled (connected to site LAN). |
When two Packeteer units are directly connected, traffic is running,
and then the direct standby feature is disabled on one of the partner
units, the copied packets coming through the direct link between the
units are leaking onto the LAN causing the receiving unit to see duplicate
packets. Note that this situation happens only for a short time period
because the unit sending the copied packets would stop sending packets
immediately upon realizing that its partner is down. |
See also:
Direct
Standby Notes
|
