HP 6125G HP 6125G & 6125G/XG Blade Switches IP Multicast Configuration - Page 132
Configuring a PIM domain border, the PIM-SM domain
View all HP 6125G manuals
Add to My Manuals
Save this manual to your list of manuals |
Page 132 highlights
• When an attacker controls a router in the network or when an illegal router is present in the network, the attacker can configure this router as a C-BSR and make it win BSR election to control the right of advertising RP information in the network. After a router is configured as a C-BSR, it automatically floods the network with bootstrap messages. Because a bootstrap message has a TTL value of 1, the whole network will not be affected as long as the neighbor router discards these bootstrap messages. Therefore, with a legal BSR address range configured on all routers in the entire network, all these routers will discard bootstrap messages from out of the legal address range. These preventive measures can partially protect the security of BSRs in a network. However, if an attacker controls a legal BSR, the problem will still occur. Because a large amount of information needs to be exchanged between a BSR and the other devices in the PIM-SM domain, a relatively large bandwidth should be provided between the C-BSRs and the other devices in the PIM-SM domain. For C-BSRs interconnected via a tunnel, multicast static routes need to be configured to make sure that the next hop to a C-BSR is a tunnel interface. For more information about multicast static routes, see "Configuring multicast routing and forwarding." To configure a C-BSR: Step 1. Enter system view. 2. Enter PIM view. 3. Configure an interface as a C-BSR. Command system-view pim c-bsr interface-type interface-number [ hash-length [ priority ] ] 4. Configure a legal BSR address range. bsr-policy acl-number Remarks N/A N/A No C-BSRs are configured by default. Optional. No restrictions on BSR address range by default. Configuring a PIM domain border As the administrative core of a PIM-SM domain, the BSR sends the collected RP-set information in the form of bootstrap messages to all routers in the PIM-SM domain. A PIM domain border is a bootstrap message boundary. Each BSR has its specific service scope. A number of PIM domain border interfaces partition a network into different PIM-SM domains. Bootstrap messages cannot cross a domain border in either direction. Perform the following configuration on routers that you want to configure as a PIM domain border. To configure a PIM domain border: Step 1. Enter system view. 2. Enter interface view. 3. Configure a PIM domain border. Command system-view interface interface-type interface-number pim bsr-boundary Remarks N/A N/A By default, no PIM domain border is configured. 121