42Usage guidelinesThis command takes effect only when the device acts as a PPPoE server or L2TP LNS.A PPPoE or L2TP user might request multiple services of different IP address types. By default, thedevice logs off the user if the user does not obtain an IPv4 address. This command enables thedevice to allow the user to come online if the user has obtained IP addresses of all the specifiedtypes for the basic services.The device does not allow a PPPoE or L2TP user to come online if the user does not obtain IPaddresses of all the specified types for the basic services. For example, if you execute thebasic-service-ip-type ipv6 command, the device does not allow a PPPoE or L2TP user to comeonline if the user does not obtain an IPv6 address.If you specify both the ipv6 and ipv6-pd keywords, the device does not allow a PPPoE or L2TP userthat fails IPv6 address negotiation or PD negotiation to come online.Examples# In ISP domain test, specify PPPoE and L2TP users to rely on IPv4 addresses to use the basicservices. system-view[Sysname] domain test[Sysname-isp-test] basic-service-ip-type ipv4dhcpv6-follow-ipv6cpUse dhcpv6-follow-ipv6cp to set the DHCPv6 request timeout timer for PPPoE and L2TP users.Use undo dhcpv6-follow-ipv6cp to restore the default.Syntaxdhcpv6-follow-ipv6cp timeout delay-timeundo dhcpv6-follow-ipv6cpDefaultThe DHCPv6 request timeout timer for PPPoE and L2TP users is 60 seconds.ViewsISP domain viewPredefined user rolesnetwork-adminParameterstimeout delay-time: Specifies the DHCPv6 request timeout timer, in the range of 30 to 120 seconds.Usage guidelinesThis command takes effect only when the device acts as a PPPoE server or L2TP LNS.After the device finishes IPv6CP negotiation with a PPPoE or L2TP user, PPP instructs DHCPv6 toassign an IPv6 address to the user. The user cannot come online if the IP address assignment failswithin the DHCPv6 request timeout timer and the user basic service relies on an IPv6 address.As a best practice, increase the DHCPv6 request timeout timer in the following situations:• The network communication is unstable.• The ISP domain serves a large number of PPPoE and L2TP users.
