Overview ························································································································································ 260
Implementation ······································································································································· 260
Tunnel modes ········································································································································ 260
Configuration example ··························································································································· 261
Overview ························································································································································ 265
Configuration example ··································································································································· 266
Configuring GRE ······················································································· 270
Overview ························································································································································ 270
GRE encapsulation format ····················································································································· 270
GRE application scenarios ····················································································································· 271
Protocols and standards ························································································································ 273
Configuring a GRE/IPv4 tunnel ······················································································································ 273
Configuration guidelines ························································································································· 273
Configuration procedure ························································································································· 274
Configuring a GRE/IPv6 tunnel ······················································································································ 275
Configuration guidelines ························································································································· 275
Configuration procedure ························································································································· 275
Displaying and maintaining GRE ··················································································································· 276
GRE configuration examples ························································································································· 277
Troubleshooting GRE····································································································································· 282
Symptom ················································································································································ 282
Analysis ·················································································································································· 282
Solution ·················································································································································· 283
About HTTP redirect ······································································································································ 284
Conventions ··················································································································································· 286
Network topology icons ·································································································································· 287
Accessing updates ········································································································································· 288
Websites ················································································································································ 289
Customer self repair ······························································································································· 289
Remote support ······································································································································ 289
Documentation feedback ······················································································································· 289
Index ·········································································································· 291
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