Technical data

ServerIron ADX NAT64 Configuration Guide 101
53-1002288-02
Stateless static IP NAT
6
DRAFT: BROCADE CONFIDENTIAL
The syn-timeout keyword indicates timeout for NAT TCP flows after a SYN
The tcp-timeout keyword indicates dynamic entries that use PAT based on TCP port numbers. The
default is 120 seconds. This timer applies only to TCP sessions that do not end “gracefully”, with a
TCP FIN or TCP RST.
The udp-timeout keyword indicates dynamic entries that use PAT based on UDP port numbers. The
default is 120 seconds.
The <secs> parameter specifies number of seconds, 0– 3600. Use maximum to set the maximum
timeout value. For example, 3,600 seconds.
The max-entries <number-of-entries> parameter specifies the maximum number of NAT entries
Stateless static IP NAT
A ServerIron ADX creates sessions for Static NAT by default. You can prevent a ServerIron ADX from
creating sessions for static NAT traffic with the following command.
ServerIronADX(config)# [no] ip nat stateless
Syntax: ip nat stateless
For “ip nat stateless“ to work, the existing command, “ip nat inside source static” must already be
configured.
Example
ip nat inside source static 10.45.16.103 10.45.16.10
NOTE
FTP, RTSP and other similar complex protocols are not supported. The traffic applicable for IP NAT
Stateless are TCP, UDP, and ICMP.
NOTE
You must reload a ServerIron ADX whenever changes are made to a running IP NAT configuration.
Redundancy
The IP NAT Redundancy feature implements a separate protocol to negotiate IP address ownership
of NAT IP addresses.
The new protocol is similar to the symmetric VIP protocol and uses any L2 link to exchange the NAT
PDUs. Both ServerIronADXs will run a “symmetric VIP like” protocol to report and receive ownership
(similar to the VLAN AD protocol in symmetric SLB). When one ServerIron ADX goes down, the peer
ServerIron ADX will become the master for that NAT IP (in case of static NAT) or NAT pool (in case of
dynamic NAT). However, the NAT IP/NAT pool ownership is used only to decide which ServerIronADX
responds to the ARP request for the NAT IP. Both ServerIronADXs are allowed to use the NAT IP in
keeping with the design for symmetric VIP (sym-active SLB).
The global ip policy dependency is as follows:
• SLB — not needed
• IP NAT — not needed