Technical data

18 ServerIron ADX NAT64 Configuration Guide
53-1002444-02
High availability for stateful NAT64
2
DRAFT: BROCADE CONFIDENTIAL
For more information about NAT64 fragmentation support, refer to “NAT64 fragmentation support”
on page 5.
NOTE
The ipv6-frag-full-4to6 command was introduced in ServerIron ADX release 12.4.00 and it replaces
the frag-664-reverse-full-sized-pkt command from earlier releases.
If the IPv4 host sends out fragmented UDP packets with checksum 0, the translation of those
packets from IPv4 to IPv6 is not supported.
High availability for stateful NAT64
The ServerIron ADX only supports Active-Active high availability (HA) mode with NAT64. In
Active-Active HA mode, the NAT64 IPv4 NAT pool ports for each NAT IP address are divided equally
among ServerIron ADX HA partners. This feature is available only for a ServerIron ADX running
router code.
Figure 6 shows a sample NAT64 configuration in which each ServerIron ADX is configured with a
NAT64 prefix and an IPv4 NAT pool with the port-pool-range option that specifies the IPv4 NAT pool
port ownerships. Sessions are synchronized periodically between the ServerIron ADX HA partners
using a separate link.
FIGURE 6 NAT64 Active-Active HA configuration
NOTE
Fragmented traffic sessions do not sync in HA mode.
Configuring the port pool range for HA
When Active-Active HA is configured on a ServerIron ADX, you can specify the range of source ports
allocated for the NAT IP address for each of the NAT64 gateways configured within the HA setup
using the nat64 pool command with the port-pool-range option.
The port-pool-range option enables NAT64 redundancy. A value of 2 specifies a higher priority of
the NAT IP address then a value of 1. A value of 2 also indicates that source ports allocated for the
NAT IP address are from the higher range.
For example, the following command configures an IPv4 NAT address pool with the port-pool-range
option set to a value of 2.
Active
ADX - 1
Data
Upstream Router
Downstream Router
NAT64
Active
ADX - 2
Session - Sync
NAT64