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NAT configuration ······················································································································································· 1
Overview ············································································································································································ 1
Introduction to NAT ·················································································································································· 1
NAT implementation ················································································································································ 2
Low-priority address pool ········································································································································ 5
Configuring a NAT policy in the web interface ············································································································ 6
Configuration overview ··········································································································································· 6
Creating an address pool ······································································································································· 7
Configuring dynamic NAT ······································································································································ 8
Creating a static address mapping ························································································································ 9
Enabling static NAT on an interface ··················································································································· 11
Creating an internal server ··································································································································· 11
Configuring a DNS mapping ······························································································································· 14
NAT configuration examples ······························································································································· 14
Configuring a NAT in the CLI ······································································································································· 17
NAT configuration task list ··································································································································· 17
Configuring address translation··························································································································· 17
Configuring an internal server ····························································································································· 20
Configuring DNS mapping ·································································································································· 21
Setting NAT connection limits ······························································································································ 21
Displaying and maintaining NAT ························································································································ 21
NAT configuration examples ······························································································································· 22
Troubleshooting NAT ····················································································································································· 26
Symptom 1: abnormal translation of IP addresses ···························································································· 26
Symptom 2: internal server functions abnormally ······························································································ 26
Configuration guidelines ··············································································································································· 26
Application level gateway configuration ················································································································· 27
ALG overview ································································································································································· 27
Configuring ALG in the web interface ························································································································· 29
Enabling ALG ························································································································································· 29
ALG configuration examples ········································································································································ 29
FTP ALG configuration example ·························································································································· 29
SIP/H.323 ALG configuration example ············································································································· 31
NBT ALG configuration example ························································································································· 32
Configuring ALG in the command line interface ········································································································ 34
Enabling ALG ························································································································································· 34
ALG configuration examples ································································································································ 34
Index ··········································································································································································· 38
