iv
Configuring DNS ······················································································································································· 76
Overview········································································································································································· 76
Static domain name resolution····························································································································· 76
Dynamic domain name resolution ······················································································································· 76
DNS proxy ····························································································································································· 77
DNS spoofing ························································································································································ 78
DNS configuration task list············································································································································ 79
Configuring the IPv4 DNS client ·································································································································· 80
Configuring static domain name resolution········································································································ 80
Configuring dynamic domain name resolution ·································································································· 80
Configuring the IPv6 DNS client ·································································································································· 81
Configuring static domain name resolution········································································································ 81
Configuring dynamic domain name resolution ·································································································· 82
Configuring the DNS proxy ·········································································································································· 82
Configuring DNS spoofing ··········································································································································· 83
Specifying the source interface for DNS packets ······································································································· 83
Configuring the DNS trusted interface ················································································································ 84
Displaying and maintaining IPv4 DNS ························································································································ 84
IPv4 DNS configuration examples ······························································································································· 85
Static domain name resolution configuration example ····················································································· 85
Dynamic domain name resolution configuration example ··············································································· 86
DNS proxy configuration example······················································································································ 88
IPv6 DNS configuration examples ······························································································································· 90
Static domain name resolution configuration example ····················································································· 90
Dynamic domain name resolution configuration example ··············································································· 91
DNS proxy configuration example······················································································································ 95
Troubleshooting IPv4 DNS configuration ···················································································································· 96
Symptom
································································································································································· 96
Solution ··································································································································································· 96
Troubleshooting IPv6 DNS configuration ···················································································································· 96
Symptom
································································································································································· 96
Solution ··································································································································································· 96
Configuring DDNS ····················································································································································· 98
Overview········································································································································································· 98
DDNS application ················································································································································· 98
DDNS client configuration task list ······························································································································· 99
Configuring a DDNS policy
·········································································································································· 99
Configuration prerequisites ································································································································ 100
Configuration procedure ···································································································································· 100
Applying the DDNS policy to an interface················································································································ 101
Displaying DDNS ························································································································································· 102
DDNS configuration examples ··································································································································· 102
DDNS configuration example with www.3322.org ······················································································· 102
DDNS configuration example with PeanutHull server ····················································································· 103
Basic IP forwarding on the device ························································································································· 105
FIB table ········································································································································································ 105
Displaying FIB table entries········································································································································· 105
Optimizing IP performance ···································································································································· 107
Enabling an interface to receive and forward directed broadcasts destined for the directly connected network
······················································································································································································· 107
Configuration procedure ···································································································································· 107
Configuration example ······································································································································· 107
Configuring MTU for an interface ······························································································································ 108