Juniper JN0-664 Dumps

OSPFv3 is an extension of OSPFv2 that supports IPv6 routing and addressing. OSPFv3 is not backward compatible with IPv4 because it uses a different packet format and a different link-state advertisement (LSA) structure than OSPFv2. OSPFv3 also uses IPv6 link-local addresses as router IDs and neighbor addresses, instead of IPv4 addresses. To use OSPFv3 for an IPv4 environment, you need to enable the IPv4 unicast address family under [edit protocols ospf3] hierarchy level and configure IPv4 addresses on the interfaces.

 IS-IS is an interior gateway protocol that uses link-state routing to exchange routing information among routers within a single autonomous system. IS-IS uses two types of packets to synchronize link-state databases among routers: Link State Packets (LSPs) and Partial Sequence Number Packets (PSNPs). LSPs contain information about the state and cost of links in the network, and are flooded periodically throughout the network. PSNPs are used to acknowledge receipt of LSPs and request retransmission of missing or corrupted LSPs. PSNPs contain only descriptions of LSPs, such as their sequence numbers and checksums3. IS-IS also uses another type of packet called Complete Sequence Number Packets (CSNPs), which are used to summarize the entire link-state database at regular intervals or when a new adjacency is formed. CSNPs are flooded periodically throughout the network and contain only descriptions of LSPs4. Therefore, PSNPs contain only descriptions of LSPs and CSNPs are flooded periodically.

References: 3: https://www.juniper.net/documentation/us/en/software/junos/routing-policy/topics/concept/routing-policy-is-is-partial-sequence-number-packet-psnp.html  4: https://www.juniper.net/documentation/us/en/software/junos/routing-policy/topics/concept/routing-policy-is-is-complete-sequence-number-packet-csnp.html

VPLS is a Layer 2 VPN technology that allows multiple sites to connect over a shared IP/MPLS network as if they were on the same LAN. VPLS tunnels can be signaled using either Label Distribution Protocol (LDP) or Border Gateway Protocol (BGP). In this question, we have two links between R1 and R2 with different bandwidths (10 Gbps and 1 Gbps). We want to use both links as much as possible for VPLS traffic. To achieve this, we need to enable per-prefix load balancing on both routers. Per-prefix load balancing is a feature that allows a router to distribute traffic across multiple equal-cost or unequal-cost paths based on the destination prefix of each packet. This improves the utilization of multiple links and provides better load sharing than per-flow load balancing, which distributes traffic based on a hash of source and destination addresses4. Per-prefix load balancing can be enabled globally or per interface using the load-balance per-packet command.