Hitachi GR2000 - Manual (Page 248)

over IPv4 tunnel is shown in Table 4-66. The total number of both tunnel interfaces
must be lower than the value shown in Table 4-66
4.2.12.8 Maximum Number of IPv6 Addresses to be Set
The maximum number of IPv6 addresses that can be set using configuration
Table 4-66 Number of Tunnel Interfaces
Router Model
Number of interfaces
IPv4 over IPv6
IPv6 over IPv4 Per Router
GR2000-2S 256 256 256
GR2000-4S 1024 1024
GR2000-6H
GR2000-10H
GR2000-20H
(Note) For previous versions, the number of settings is 256 in all cases. When setting 1024 interfaces,
use of RP-C6/RP-D6 is a prerequisite.