4A0-103 Nokia Multi Protocol Label Switching Questions and Answers

R4 (10.10.10.4) has established a link protection tunnel.

R6 (10.10.10.6) has established a link protection tunnel.

R2 (10.10.10.2) has established a node protection tunnel.

R1 (10.10.10.1) has not established a node protection tunnel.

The router does not have a route to reach to the peer 10.10.10.2/32.

The router does not have a route to reach to the prefix 192.10.1.2/32.

The router does not have an export policy defined to export the prefix 192.10.1.2/32 into LDP.

The router receives an invalid label for the prefix 192.10.1.2/32 from its peer.

Send a PathTear message towards router R6.

Send a PathTear message towards router R1.

Send a ResvTear message toward router R6.

Send a ResvTear message toward router R1.

Static LSPs

Reserved use

Vendor proprietary use

Management LSPs

Dynamic LSPs

Notification

Session

Discovery

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A PUSH label stack operation must be performed.

The outgoing interface and next-hop address will be determined from the FIB.

The packet can be forwarded as a labeled or unlabeled packet.

A POP label stack operation may be performed.

The router must build the Path State Block (PSB).

The router must build the Reservation State Block (RSB).

The router must build the Session State Block (SSB)

The router must send the second RESV refresh message.

The router must receive the second PATH refresh message.

Link-based and T-LDP sessions may be configured on the same LSR.

T-LDP supports sessions between non-directly connected devices.

T-LDP can be configured between directly connected devices.

T-LDP Hello messages are sent to a multicast address.

Send a PathTear message towards router R6.

Send a PathTear message towards router R1.

Send a ResvTear message toward router R6.

Send a ResvTear message toward router R1.

A packet arriving with label 131066 will be forwarded out interface 1 /1 /4 with label 131070.

The router is an egress router for FEC 10.10.10.221/32.

There are multiple LSPs to reach FEC 10.10.10.244/32.

The router's system address is 10.10.10.242/32.

1

2

3

4

Liberal label retention mode

T-LDP enabled with peers to which load balancing is desired.

ECMP enabled in the config>router context.

Hashing used to select the egress label.

Export policy applied to advertise multiple labels for a given FEC.

It makes use of MPLS resiliency features available within an AS.

It eliminates double route lookups on all routers within an AS.

It eliminates the need to run IGP on all routers within an AS.

It eliminates the need for an iBGP full mesh on all core routers.

When the reserved bandwidth goes above 80M.

When the reserved bandwidth goes above 40M.

When an additional 80M bandwidth is reserved.

When an additional 40M bandwidth is reserved.

The MPLS TTL values are incremented at each request.

The router uses MPLS Echo Request packets that are IP-routed.

The router collects hop information along the tunnel's path.

The router performs an unidirectional LSP test.

The LSP will switch to R1-R3-R5-R6 after the resignal timer expires.

The old primary path and its detours are torn down after the new primary path is established.

CSPF must be enabled to find a more optimal path.

The traffic is switched to R1-R3-R5-R6 in an MBB fashion.

RSVP generates a summary refresh message for each LSP.

Message-IDs replace individual refresh messages.

An LSP state change causes the Message-ID to be incremented.

RSVP refresh reduction is disabled by default.

Router R1 updates its FIB after a new SPF calculation.

Router R1 switches to a secondary path.

Router R4 switches to a FRR path.

Router R4 switches to a standby secondary path.

Admin groups

Hop-limit

Strict hops

TE-Metric

The router can reach prefix 192.10.1.2/32 through a RSVP-TE tunnel.

The router can reach prefix 192.10.1.2/32 through an LDP tunnel.

The router 10.10.10.2 is the egress router of the prefix 192.10.1.2/32.

The Isp-ping tool is used to perform a unidirectional LSP test.

The inner label will be exchanged with the MPLS outer label.

The inner label will be exchanged for a new label.

The outer label will be exchanged for a new label.

All labels will be exchanged for one new label.

All labels will be exchanged for an equal number of new labels.

Push an additional label onto the label stack.

Pop the label.

Swap the label.

Pop the label and push an additional label onto the label stack.

The penultimate router will POP the top label from the packets.

The eLER will receive packets with a top label value of 3.

The eLER will receive packets with a top label value of 0.

The penultimate router will always receive unlabeled packets.

The penultimate router performs a double lookup on the packet.

Ordered control mode; downstream on demand.

Ordered control mode; downstream unsolicited.

Independent control mode; downstream on demand.

Independent control mode; downstream unsolicited.

CSPF looks for the delta bandwidth, taking down the first path if necessary.

CSPF looks for the delta bandwidth, implementing make-before-break.

After 5 failed attempts to find the bandwidth requested, the head end disables the LSP.

CSPF looks for the entire bandwidth requested, implementing MBB.

The IGP FIB.

The Reservation State Block (RSB)

The Path State Block (PSB)

The opaque database.

4

1

5

6

Fast reroute requires you to manually define detour paths.

Fast reroute provides path protection close to the failure point

Fast reroute performs automatic path calculation and signaling.

Fast reroute protects both primary and secondary paths.

Targeted sessions must exist between all routers in the tunnel's path.

Each LDP interface must be configured to support LDP tunneling.

LDP prefixes resolve to an RSVP LSP, rather than to a physical egress interface.

RSVP LSPs must exist between each PE-ABR pair, or ABR-ABR pair in each area.

Tunnel ID

Name

LSP ID

To

CSPF chooses a link that is a member of both administrative groups

CSPF chooses only those links that are NOT members of the green admin group

CSPF prunes the green links and uses these links for the secondary path

CSPF signals the LSP path over the green links only, and prunes all other links

IGP-based LSPs are established solely from information contained in routing tables.

The constraint-based routed LSP is calculated at the ingress of the network, based on the router database and user defined constraints.

The constraint-based routed LSP is calculated at each hop of the LSP, based on the route table and user defined constraints.

IGP-based LSPs must use LDP signaling.

10 Gbps

7 Gbps

3 Gbps

2 Gbps

A router will never receive a packet containing this label value.

Request a new label from the peer that provided this label.

Pop the label.

PUSH an additional label onto the label stack.

Signal a new label to the peer that sent the packet.