Dell Force10 E1200i FTOS Version 8.4.1.5 Configuration Guide for ExaScale - Page 719

• The router holds on to the entries learned from the neighbor for the graceful restart interval. If it does not receive a hello from the neighbor within this time, it purges all state associated with the neighbor. • If the neighbor restarts and sends a hello with a new GenID before this interval expires, the router sends a join message towards the neighbor for the relevant entries. If a graceful-restart capable router restarts, the router preserves all multicast entries in hardware until it receives and consolidates joins from its graceful-restart capable neighbors. The router is not taken off the forwarding path during restart. Enable PIM-SM graceful restart (non-stop forwarding capability) using the command ip pim graceful-restart nsf from CONFIGURATION mode. There are two options with this command: • restart-time is the time required by the Dell Force10 system to restart. The default value is 180 seconds. • stale-entry-time is the maximum amount of time that the Dell Force10 system preserves entries from a restarting neighbor. The default value is 60 seconds. In helper-only mode, the system preserves the PIM states of a neighboring router while the neighbor gracefully restarts, but the Dell Force10 system allows itself to be taken off the forwarding path if it restarts. Enable this mode using the command ip pim graceful-restart helper-only. This mode takes precedence over any graceful restart configuration. First Packet Forwarding for Lossless Multicast When the Dell Force10 system is the RP, packets arriving before an (S,G) entry is created are soft forwarded using the (*,G) entry. This provides for zero multicast packet loss on FTOS with two exceptions: 1. These packets can be soft (slow path) forwarded to receivers at a maximum rate of 70 packets/second. Incoming packets beyond this rate are dropped. 2. When the system is both the source-DR and the RP, in some cases, packet loss, packet reordering, or duplicate packets might occur. To prevent these delivery errors you must statically map the potential incoming interfaces for the (*,G) entries via the CLI. When you create this mapping, (*,G) entries are programmed in hardware. Packets are then fast forwarded starting with the first packet, and the potential for these delivery errors is avoided. Step 1 Task Command Syntax Command Mode Create a standard access-list that permits one or more IGMP groups. ip access-list standard name FTOS(config-std-nacl)#show config ! ip access-list standard map1 seq 5 permit 224.0.0.0/24 CONFIGURATION PIM Sparse-Mode | 719