RIP runs between a PPPoE client and the firewall serving as the LNS. The PPPoE client cannot receive RIP packets from the firewall during traffic peak; however, RIP debugging information shows that RIP packets are already sent from the control plane. What is the cause?
RIP packets, as multicast packets, are sent to all dial-up users through a VT interface. If multiple routes exist, multicast or broadcast packets issued to each dial-up user exert adverse impacts on device performance. By default, when the number of dial-up users exceeds 30, the multicast or broadcast packets sent by the firewall are not sent to over an L2TP tunnel. You can run the broadcast-limit link command in the VT interface view to limit the number of multicast or broadcast packets sent per second. The value ranges from 0 to 128.