Failover time in a multi-path topology, Modifying the ttl, Pim sparse – Brocade BigIron RX Series Configuration Guide User Manual

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BigIron RX Series Configuration Guide

53-1002484-04

PIM Sparse

24

Failover time in a multi-path topology

Previously, when a port in a multi-path topology fails, multicast routers, depending on the routing
protocol being used, take a few seconds to establish a new path, if the failed port is the input port
of the downstream router.

No configuration is required for this feature.

Modifying the TTL

The TTL defines the minimum value required in a packet for it to be forwarded out of the interface.

For example, if the TTL for an interface is set at 10, it means that only those packets with a TTL
value of 10 or more will be forwarded. Likewise, if an interface is configured with a TTL Threshold
value of 1, all packets received on that interface will be forwarded. Possible TTL values are 1 to 64.
The default TTL value is 1.

To configure a TTL of 45, enter the following.

BigIron RX(config-if-e10000-3/24)# ip pim ttl 45

Syntax: ip pim ttl <1-64>

PIM Sparse

The BigIron RX supports Protocol Independent Multicast (PIM) Sparse version 2. PIM Sparse
provides multicasting that is especially suitable for widely distributed multicast environments. The
Brocade implementation is based on RFC 2362.

In a PIM Sparse network, a PIM Sparse router that is connected to a host that wants to receive
information for a multicast group must explicitly send a join request on behalf of the receiver (host).

PIM Sparse routers are organized into domains. A PIM Sparse domain is a contiguous set of routers
that all implement PIM and are configured to operate within a common boundary.

Figure 102

shows a simple example of a PIM Sparse domain. This example shows three BigIron RX devices
configured as PIM Sparse routers. The configuration is described in detail following the figure.

Total number of IP routes: 19

B:BGP D:Connected R:RIP S:Static O:OSPF *:Candidate default

Destination NetMask Gateway Port Cost

Type

..

9 172.17.41.4 255.255.255.252*137.80.127.3 v11 2

O

172.17.41.4 255.255.255.252 137.80.126.3 v10 2

O

172.17.41.4 255.255.255.252 137.80.129.1 v13 2

O

172.17.41.4 255.255.255.252 137.80.128.3 v12 2

O

10 172.17.41.8 255.255.255.252 0.0.0.0 1/2 1

D

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