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Cisco ME 3400 EthernetAccess Switch SoftwareConfiguration Guide
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Chapter34 Configuring IP Multicast Routing
Configuring Optional Multicast Routing Features

Limiting How Long an sdr Cache Entry Exists

By default, entries are never deleted from the sdr cache. You can limit how long the entry remains acti ve
so that if a source stops advertising SAP information, old advertisements are not needlessly kept.
Beginning in privileged EXEC mode, follow these steps to limit how long a n sdr cache ent ry stays acti v e
in the cache. This procedure is optional.
To return to the default setting, use the no ip sdr cache-timeout global configuration command. To
delete the entire cache, use the clear ip sdr privileged EXEC command.
To display the session directory cache, use the show ip sdr privileged EXEC command.
Configuring an IP Multicast Boundary
Administratively-scoped boundaries can be used to limit the forwarding of multicast traffic outside of a
domain or subdomain. This approach uses a special range of multicast addresses, called
administratively-scoped addresses, as the boundary mechanism. If you configure an
administratively-scoped boundary on a routed interface, multicast traffic whose multicast group
addresses fall in this range can not enter or exit this interface, thereby providing a firewall for multicast
traffic in this address range.
Note Multicast boundaries and TTL thresholds control the scop ing of multi cast doma ins; however, TTL
thresholds are not supported by the switch. You should use multicast boundaries instead of TTL
thresholds to limit the forwarding of multicast traffic outside of a domain or a subdomain.
Figure 34-4 shows that Company XYZ has an administratively-scoped boundary set for the multicast
address range 239.0.0.0/8 on all routed interfaces at the perimeter of its net work. This boundary prevents
any multicast traffic in the range 239.0.0.0 through 239.255.255.255 from entering or leaving the
network. Similarly, the engineering and marketing departments have an administratively-scoped
boundary of 239.128.0.0/16 around the perimeter of their ne tworks . Thi s bou ndary pr events multi cast
traffic in the range of 239.128.0.0 through 239.128.255.255 from e nter ing or leaving thei r resp ec tive
networks.
Command Purpose
Step1 configure terminal Enter global configuration mode.
Step2 ip sdr cache-timeout minutes Limit how long an sdr cache entry stays active in the cache.
By default, entries are never deleted from the cache.
For minutes, the range is 1 to 4294967295.
Step3 end Return to privileged EXEC mode.
Step4 show running-config Verify your entries.
Step5 copy running-config startup-config (Optional) Save your entries in the configuration file.