 | Copyright © 2009, Juniper Networks, Inc. All rights reserved. Trademark Notice. | |
MSDP data encapsulation mainly concerns bursty sources of multicast traffic. Sources that send only one packet every few minutes have problems with the timeout of state relationships between sources and their multicast groups (S,G). Routers lose data while they attempt to reestablish (S,G) state tables. So multicast register messages contain data, and this data encapsulation in MSDP source-active messages can be turned on or off through configuration.
By default, MSDP data encapsulation is enabled. An RP running MSDP takes the data packets arriving in the source's register message and encapsulates the data inside an MSDP source-active message.
However, data encapsulation creates both a multicast forwarding cache entry in the inet.1 table (this is also the forwarding table) and a routing table entry in the inet.4 table. Without data encapsulation, MSDP creates only a routing table entry in the inet.4 table. In some circumstances, such as the presence of Internet worms or other forms of denial-of-service (DoS) attack, the router's forwarding table may fill up with these entries. To prevent the forwarding table from filling up with MSDP entries, you can configure the router not to use MSDP data encapsulation. However, if you disable data encapsulation, the router ignores and discards the encapsulated data. Without data encapsulation, multicast applications with bursty sources having transmit intervals greater than about 3 minutes might not work well.
To configure MSDP data encapsulation on the router, include the data-encapsulation statement:
-
data-encapsulation (enable | disable);
You can include this statement at the following hierarchy levels:
You should also configure the router to be a PIM sparse-mode RP. For more information about configuring PIM, see PIM Configuration Guidelines.
| Copyright © 2009, Juniper Networks, Inc. All rights reserved. Trademark Notice. | |