Specifications

Enabling Outbound NAT
Equalizer Installation and Administration Guide 53
After Equalizer comes back up, you can create a failover configuration.
Enabling Outbound NAT
If you use a reserved network configuration and the servers on the non-routable network must be
able to communicate with hosts on the Internet, you must configure Equalizer to perform outbound
network address translation (NAT). When outbound NAT is enabled, Equalizer translates the source
IP address in all packets originating from the servers on the reserved network to Equalizer's
external IP address, so that clients do not see packets originating from non-routable IP addresses.
To enable Equalizer to perform outbound NAT, follow these steps:
1. Log into the Equalizer Administration Interface in edit mode.
2. Select Equalizer > Global Configuration from the Equalizer menu in the main menu bar. The
modify system parameters screen appears in the right frame (see Figure 22 on page 43).
3. Check the enable outbound NAT checkbox.
4. Click the commit button.
Enabling Passive FTP Connections
If your servers are on a network the outside world cannot reach, consider enabling Equalizer’s
passive FTP translation option. This option causes the Equalizer to rewrite outgoing FTP PASV
control messages from the servers so they contain the IP address of the virtual cluster rather than
that of the server.
To enable passive FTP translation, follow these steps:
1. Log into the Equalizer Administration Interface in Edit mode.
2. Select Equalizer > Global Configuration from the Equalizer menu in the main menu bar. The
modify system parameters screen appears in the right frame (see Figure 22 on page 43).
3. Check the passive FTP translation checkbox.
4. Click the commit button.
Managing Stale Connections
The stale connection timeout is the length of time that a partially open or closed connection is
maintained. If a client fails to complete the TCP connection termination handshake sequence or
sends a SYN packet but does not respond to the server’s SYN/ACK, Equalizer marks the
connection as incomplete. Equalizer reclaims connections in the incomplete state when the stale
connection timeout expires. When Equalizer reclaims a connection, it sends a TCP RST (reset)
packet to the server, enabling the server to free any resources associated with the connection. Stale
connections apply to Layer 4 (L4) only.
Note – If you use outbound NAT in a failover configuration, you should enable outbound NAT on
both units in case a failover actually occurs.