Service Provider Routing and Switching, Professional (JNCIP-SP)

To ensure load balancing over multiple eBGP paths from different autonomous systems, the 'multipath multiple-as' parameter must be configured under the global BGP configuration. By default, BGP multipath functionality only applies to paths from the same AS; adding the 'multiple-as' parameter extends this functionality to paths from different ASes. This allows for proper load balancing between the routes learned from R1 and R3, which are in different autonomous systems (65001 and 65003 respectively).

To ensure that R1 is configured properly for load balancing BGP routes, you need to perform the following actions: First, verify that the routing table on R1 has BGP routes for 203.0.113.128/25 with multiple next hops to ensure that multiple paths are available. Next, verify that there is a load balancing export policy under routing-options for the received BGP routes on R1, which would ensure that load balancing is appropriately handled on the router. Finally, verify that the multipath option is configured under protocols bgp on R1, enabling the router to use multiple paths for BGP routes. The configurations on R2 and R3 are not required to enable load balancing on R1.

To reduce the impact caused by suboptimal routing in your OSPF and OSPFv3 network after devices reboot, you need to configure an overload state with a timeout. This prevents the network device from routing traffic through it temporarily, allowing other devices to stabilize and preventing suboptimal routing decisions. Setting 'set protocols ospf overload timeout 900' and 'set protocols ospf3 overload timeout 900' accomplishes this by putting OSPF and OSPFv3 devices into an overload state with a 900-second timer to revert. Additionally, 'set protocols ospf3 realm ipv4-unicast overload timeout 900' is used to specify this for IPv4 in OSPFv3.

To achieve load balancing and redundancy in a PIM-SM domain and share active sources between RPs, you need to configure MSDP (Multicast Source Discovery Protocol) on each RP router. MSDP allows RPs to exchange information about active multicast sources, ensuring all RPs are aware of the sources available throughout the network. Additionally, configuring anycast PIM with the rp-set statement on each RP router enables the use of the same IP address across multiple RPs for load balancing and redundancy. These configurations ensure that multicast sources are effectively shared and managed between the RPs.

LDP-signaled VPLS tunnels only support control bit 0, which means that as far as control bits are concerned, only bit 0 is used in these tunnels. Also, BGP-signaled VPLS tunnels can use either RSVP or LDP between the PE routers. This is because the signaling method (BGP in this case) is separate from the underlying transport method (RSVP or LDP).