HP Storage Mirroring V5.1 Software - Manual (Page 53)

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Establishing a
Connection Across a
NAT or Firewall
If you are in an IPv4 environment and your source and target are on opposite sides of a NAT or
firewall, you will need to configure your NAT or firewall to accommodate Storage Mirroring
communications. You must have the hardware already in place and know how to configure the
hardware ports. If you do not, see the reference manual for your hardware.
In this environment, you must have static mapping where a single, internal IP address is always
mapped in a one-to-one coorelation to a single, external IP address. Storage Mirroring cannot handle
dynamic mappings where a single, internal IP address can be mapped to any one of a group of
external IP addresses managed by the router.
Verifying the Storage Mirroring port settings
Storage Mirroring uses specific ports for communication between the Storage Mirroring servers and
Storage Mirroring clients. In order to use Storage Mirroring through a NAT or firewall, you must first
verify the current Storage Mirroring port settings so that you can open the correct ports on your
hardware to allow Storage Mirroring machines to communicate with each other.
By default, Storage Mirroring uses port 6320 for all communications. Locate and record your port
settings for each of the Storage Mirroring components. The port setting can be found in the following
locations.

Management Console—From the Management Console, select File, Options, and go to the
Configuration tab.

Failover Control Center—From the Failover Control Center, select Settings,
Communications.

Storage Mirroring server—From the Management Console, right-click on a server in the tree in
the left pane of the Management Console, select Properties, and go to the Network tab.
Configuring the hardware
You need to configure your hardware so that Storage Mirroring traffic is permitted access through the
router and directed appropriately. Configure your hardware identifying each Storage Mirroring server,
its IP address, and the Storage Mirroring and router ports. Also, note the following caveats.

Since Storage Mirroring communication occurs bidirectionally, make sure you configure your
router for both incoming and outgoing traffic for all of your Storage Mirroring servers and Storage
Mirroring clients.

Storage Mirroring failover can use ICMP pings to determine if the source server is online. If you
are going to use ICMP pings and a router between the source and target is blocking ICMP traffic,
failover monitors cannot be created or used. In this situation, you must configure your router to
allow ICMP pings between the source and target.
Since there are many types of hardware on the market, each can be configured differently. See your
hardware reference manual for instructions on setting up your particular router.
NOTE: If you change any of the port settings, you must stop and restart the Storage Mirroring
service for the new port setting to take effect.