7 
 
11.2 Flow Control .......................................................................................................................................... 72 
12 VPN ...................................................................................................................................................................73 
12.1 IPSec ........................................................................................................................................................73 
12.2 GRE .........................................................................................................................................................79 
12.3 .......................................................................................................................................................... ….. ...88   
12.4 Certificate Management ......................................................................................................................85 
12.5 DMVPN ..................................................................................................................................................86 
13 Tools ...................................................................................................................................................................95 
13.1 PING detection ......................................................................................................................................95 
13.2 Routing detection ..................................................................................................................................96 
13.3 Internet Speed Testing .......................................................................................................................... 97 
14 Typical Networking Configuration Examples...........................................................................................98 
15 Appendix - Setting of Command Line ...................................................................................................... 101 
15.1 Set up Configuration Environment through the Console Port ................................................... 102 
15.2 Online Help of Command Line ........................................................................................................ 104 
15.3 Command Line Operation ................................................................................................................. 105 
16 Appendix - Troubleshooting ....................................................................................................................... 107 
17 Appendix - Default Settings ........................................................................................................................ 110 
18 Appendix - Glossary of Terms.................................................................................................................... 111