Failover Time In A Multi-Path Topology; Modifying The Ttl; Pim Sparse - Dell PowerConnect B-RX Configuration Manual

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PIM Sparse

Selection of shortest path back to source
By default, when a multicast packet is received on a PIM-capable router interface in a multi-path
topology, the interface checks its IP routing table to determine the shortest path back to the
source. If the alternate paths have the same cost, the first alternate path in the table is picked as
the path back to the source. For example, in the table below, the first four routes have the same
cost back to the source. However, 137.80.127.3 will be chosen as the path to the source since it is
the first one on the list. The router rejects traffic from any port other than Port V11 on which
137.80.127.3 resides.
Type
O
O
O
O
D

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 device 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.
596
Total number of IP routes: 19
B:BGP D:Connected R:RIP
Destination
..
9 172.17.41.4
172.17.41.4
172.17.41.4
172.17.41.4
10 172.17.41.8
S:Static O:OSPF *:Candidate default
NetMask Gateway
255.255.255.252*137.80.127.3
255.255.255.252 137.80.126.3
255.255.255.252 137.80.129.1
255.255.255.252 137.80.128.3
255.255.255.252 0.0.0.0
Port Cost
v11 2
v10 2
v13 2
v12 2
1/2 1
BigIron RX Series Configuration Guide
53-1001810-01