Chapter 13
To implement the intelligent SNAT, the ISP takes the following steps. First, the ISP creates a load balancing pool called out_pool. In the bigip.conf file, the pool looks like the sample in Figure 13.4. pool out_pool { lb_method round_robin member 199.5.6.254:0 member 207.8.9.254:0 }
Figure 13.4 bigip.conf entries for a pool to be used in an intelligent SNAT Next, as shown in Figure 13.5, the ISP uses the Configuration utility to create a SNAT pool called chat_snatpool containing four IP addresses: 199.5.6.10, 199.5.6.11, 207.8.9.10, and 207.8.9.11. The BIG-IP system automatically designates these IP addresses as translation addresses during creation of the SNAT pool. These addresses correspond to each of the two next hop networks that are to be used for CHAT traffic. In the bigip.conf file, the SNAT pool looks like the sample in Figure 13.5. snatpool chat_snatpool { member 199.5.6.10 member 199.5.6.11 member 207.8.9.10 member 207.8.9.11 }
Figure 13.5 A SNAT pool definition for CHAT traffic Next, for each translation address, the ISP uses the Configuration utility to change the timeout value for TCP connections to 600. Then the ISP creates a second SNAT pool, smtp_snatpool containing two translation addresses: 199.5.6.20 and 207.8.9.20. Each address corresponds to one of the two next hop networks that are to be used for SMTP traffic. In the bigip.conf file, the SNAT pool looks like the sample in Figure 13.6. snatpool smtp_snatpool { member 199.5.6.20 member 207.8.9.20 }
Figure 13.6 A SNAT pool definition for SMTP traffic
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