PIM Sparse-Mode |
765
FTOS supports PIM-SM graceful restart based on the GenID. Per RFC 4601, hello messages should
contain a Generation_Identifier option, which contains a randomly generated value (GenID) that is
regenerated each time PIM forwarding is started or restarted on the interface, including when the router
restarts. When a router receives from a neighbor a hello message with a new GenID, any old hello
information about that neighbor should be discarded and superseded by the information from the new hello
message.
FTOS supports graceful restart based on the GenID. A Dell Force10 PIM router announces its graceful
restart capability to its neighbors up front as an option in its hello messages.
If a graceful-restart capable router recognizes that a graceful-restart capable neighbor has restarted, it
preserves the state from the neighbor and continues forwarding multicast traffic while the neighbor
restarts.
•
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.
Summary of Contents for Force10 E300
Page 1: ...FTOS Configuration Guide FTOS 8 4 2 7 E Series TeraScale C Series S Series S50 S25 ...
Page 32: ...32 w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 132: ...132 802 1X w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 310: ...310 Configuration Replace and Rollback w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 330: ...330 Dynamic Host Configuration Protocol w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 402: ...402 High Availability w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 462: ...462 Interfaces w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 482: ...482 IPv4 Addressing w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 506: ...506 IPv6 Addressing w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 582: ...582 Layer 2 w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 642: ...642 Multicast Source Discovery Protocol w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 662: ...662 Multiple Spanning Tree Protocol w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 690: ...690 Object Tracking w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 754: ...754 PIM Dense Mode w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 784: ...784 PIM Source Specific Mode w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 800: ...800 Power over Ethernet w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 876: ...876 Quality of Service w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 892: ...892 Routing Information Protocol w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 1006: ...1006 Simple Network Management Protocol w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 1018: ...1018 SONET SDH w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 1048: ...1048 Broadcast Storm Control w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 1096: ...1096 Uplink Failure Detection UFD w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 1098: ...1098 Upgrade Procedures w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 1196: ...1196 C Series Debugging and Diagnostics w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 1252: ...1252 Standards Compliance w w w d e l l c o m s u p p o r t d e l l c o m ...
Page 1262: ...1262 Index w w w d e l l c o m s u p p o r t d e l l c o m ...