User's Manual

TD-W9980B
N600 Wireless Dual Band Gigabit VDSL2 Modem Router (Annex B) User Guide
Figure 4-29
 Mode: Select Main Mode to configure the standard negotiation parameters for IKE phase1.
 Aggressive Mode: Select Aggressive Mode to configure IKE phase1 of the VPN Tunnel to
carry out negotiation in a shorter amount of time. (Not Recommended-Less Secure)

Note:
The difference between the two is that aggressive mode will pass more information in fewer
packets, with the benefit of slightly faster connection establishment, at the cost of transmitting the
identities of the security firewall in the clear. When using aggressive mode, some configuration
parameters such as Diffie-Hellman groups, and PFS can not be negotiated, resulting in a greater
importance of having "compatible" configuration on both ends.
 Key Life Time:Enter the number of seconds for the IPSec lifetime. It is the period of time to
pass before establishing a new IPSec security association (SA) with the remote endpoint. The
default value is 3600.

Note:
If you want to change the default settings of Advanced Settings, please make sure that both VPN
server endpoints use the same Encryption Algorithm, Integrity Algorithm, Diffie-Hellman Group
and Key Life time in both phase1 and phase2.
4.6 DHCP Server
Choose “DHCP Server”, you can see the next submenus:
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