Cisco CCNP 350-401 ENCOR eBGP, Policy-Based Routing, and Enterprise IP Services Practice Test 1

Topic 10 Practice Test 1 covers eBGP, Policy-Based Routing, and Enterprise IP Services for Cisco 350-401 ENCOR. For broader exam preparation, review the Cisco 350-401 ENCOR Exam Dumps. Every option includes focused technical reasoning explaining both the Cisco enterprise networking concept and its fit to the scenario.

Question 1

A branch edge router in AS 65110 is directly connected to a provider router in AS 64520. The BGP neighbor remains Idle because the local configuration identifies the provider as AS 64521. Which change most directly fixes the session?

Raise the BGP local preference to 200
Apply a policy-based routing route map to the interface
Configure the neighbor with remote-as 64520
Add a static default route toward the provider

Correct Answer(s)

Rationale

Local preference influences best-path selection after routes are learned; it cannot establish a session with the wrong remote AS. Context: “a branch edge router in as 65110 is directly connected”. The controlling choice is “Configure the neighbor with remote-as 64520”. Evidence: “to a provider router in as 64520 the”.
PBR changes forwarding decisions for matching packets and does not repair BGP neighbor identity. Context: “a branch edge router in as 65110 is directly connected”. The controlling choice is “Configure the neighbor with remote-as 64520”. Evidence: “to a provider router in as 64520 the”.
The eBGP neighbor statement must name the autonomous system actually used by the directly connected peer. Correcting remote-as removes the AS-number mismatch that prevents the session from progressing. Applied to branch edge router 65110, this choice satisfies the specific ebgp remote as requirement being tested.
Reachability already exists over the directly connected link, and a default route does not correct a mismatched peer AS number. Context: “a branch edge router in as 65110 is directly connected”. The controlling choice is “Configure the neighbor with remote-as 64520”. Evidence: “to a provider router in as 64520 the”.

Question 2

Two routers in different autonomous systems are cabled back-to-back and have valid IP addresses in the same subnet. The design calls for ordinary eBGP between the directly connected interfaces. Which prerequisite is most important before troubleshooting path attributes?

Each router must have IP reachability to the peer address and a matching neighbor remote-as statement
Both routers must use the same BGP autonomous system
Both routers must advertise a default route before the session can form
The interfaces must run OSPF in area 0

Correct Answer(s)

Rationale

Directly connected eBGP still depends on basic Layer 3 reachability and correct neighbor AS configuration. Without those fundamentals, the TCP/BGP session cannot form and best-path attributes are irrelevant. Here, the ebgp direct connectivity decision is consistent with the scenario evidence around routers different autonomous systems.
Using the same AS would make the relationship iBGP rather than the required eBGP relationship. Context: “two routers in different autonomous systems are cabled back to”. The controlling choice is “Each router must have IP reachability to the peer address and a matching neighbor remote-as statement”. Evidence: “back and have valid ip addresses in the”.
Route advertisement occurs after the BGP session is established; it is not a prerequisite for forming the session. Context: “two routers in different autonomous systems are cabled back to”. The controlling choice is “Each router must have IP reachability to the peer address and a matching neighbor remote-as statement”. Evidence: “back and have valid ip addresses in the”.
An IGP is not required for directly connected eBGP peers on the same subnet. Context: “two routers in different autonomous systems are cabled back to”. The controlling choice is “Each router must have IP reachability to the peer address and a matching neighbor remote-as statement”. Evidence: “back and have valid ip addresses in the”.

Question 3

A firewall between two directly connected eBGP peers permits ICMP but blocks the transport used by BGP. Ping succeeds, yet the BGP session never reaches Established. Which transport must be permitted?

UDP destination port 4789
UDP destination port 179
TCP destination port 830
TCP destination port 179 for the BGP session

Correct Answer(s)

Rationale

UDP 4789 is the standard VXLAN data-plane port and is unrelated to the BGP transport session. Context: “a firewall between two directly connected ebgp peers permits icmp”. The controlling choice is “TCP destination port 179 for the BGP session”. Evidence: “but blocks the transport used by bgp ping”.
BGP uses TCP, not UDP, so permitting UDP 179 would not allow the peer session to establish. Context: “a firewall between two directly connected ebgp peers permits icmp”. The controlling choice is “TCP destination port 179 for the BGP session”. Evidence: “but blocks the transport used by bgp ping”.
Port 830 is commonly associated with NETCONF over SSH, not BGP peering. Context: “a firewall between two directly connected ebgp peers permits icmp”. The controlling choice is “TCP destination port 179 for the BGP session”. Evidence: “but blocks the transport used by bgp ping”.
BGP establishes its peer relationship over TCP port 179. ICMP reachability proves only basic IP connectivity and does not replace the TCP session BGP needs. Context: “a firewall between two directly connected ebgp peers permits icmp”. This answer directly implements “TCP destination port 179 for the BGP session”. Evidence: “but blocks the transport used by bgp ping”.

Question 4

A router has `network 10.44.0.0 mask 255.255.0.0` under BGP, but no 10.44.0.0/16 route exists in its routing table. The prefix is not advertised. What is the best explanation?

The prefix must first be learned by eBGP from another AS
The BGP network statement requires a matching route for that prefix and mask in the routing table
A PBR route map must be attached to the ingress interface
BGP advertises only connected /24 routes

Correct Answer(s)

Rationale

A locally originated network statement does not require the route to be learned from eBGP; it requires the route to exist in the local routing table. Context: “a router has network 10 44 0 0 mask 255”. The controlling choice is “The BGP network statement requires a matching route for that prefix and mask in the routing table”. Evidence: “255 0 0 under bgp but no 10”.
The network command does not create the route by itself. The exact prefix and mask must already be present in the RIB before BGP can originate it with that statement. The router has network mask constraints make this the appropriate ebgp network rib outcome for the design.
PBR is unrelated to BGP origination through the network statement. Context: “a router has network 10 44 0 0 mask 255”. The controlling choice is “The BGP network statement requires a matching route for that prefix and mask in the routing table”. Evidence: “255 0 0 under bgp but no 10”.
BGP can originate many prefix lengths; the problem is the missing matching RIB entry, not a /24-only restriction. Context: “a router has network 10 44 0 0 mask 255”. The controlling choice is “The BGP network statement requires a matching route for that prefix and mask in the routing table”. Evidence: “255 0 0 under bgp but no 10”.

Question 5

A router learns the same prefix from two eBGP neighbors. An engineer wants only this single router to prefer neighbor A without influencing other routers in the local AS. Which attribute is the most directly scoped choice on Cisco IOS XE?

Set a higher local preference on routes from neighbor A
Set a higher BGP weight for routes from neighbor A
Prepend the local AS toward neighbor A
Lower the MED received from neighbor A on every router

Correct Answer(s)

Rationale

Local preference is shared within the local AS through iBGP, so it is broader than the requirement to affect only one router. Context: “a router learns the same prefix from two ebgp neighbors”. The controlling choice is “Set a higher BGP weight for routes from neighbor A”. Evidence: “an engineer wants only this single router to”.
Weight is Cisco-specific and local to the router; it is not propagated to other BGP speakers. A higher weight can therefore change only this router’s best-path choice. The router learns same prefix constraints make this the appropriate bgp weight local outcome for the design.
AS-path prepending is normally used to influence how external networks choose an inbound path, not to create a purely local preference on one router. Context: “a router learns the same prefix from two ebgp neighbors”. The controlling choice is “Set a higher BGP weight for routes from neighbor A”. Evidence: “an engineer wants only this single router to”.
MED is a different path attribute and changing it across every router violates the requirement to keep the choice local. Context: “a router learns the same prefix from two ebgp neighbors”. The controlling choice is “Set a higher BGP weight for routes from neighbor A”. Evidence: “an engineer wants only this single router to”.

Question 6

Two border routers in AS 65000 learn the same Internet prefix from different providers. The company wants all routers inside AS 65000 to prefer the exit through Border-B. Which policy is most appropriate?

Configure PBR on every user-facing VLAN
Increase MED on routes learned through Border-B
Prepend AS 65000 several times on routes learned through Border-B
Set a higher local preference on routes learned through Border-B

Correct Answer(s)

Rationale

PBR could force selected traffic, but it is not the normal BGP policy mechanism for making an AS-wide best-path preference. Context: “two border routers in as 65000 learn the same internet”. The controlling choice is “Set a higher local preference on routes learned through Border-B”. Evidence: “prefix from different providers the company wants all”.
Lower MED is generally preferred and MED is mainly a signal to a neighboring AS, so increasing it does not meet the internal outbound-path requirement. Context: “two border routers in as 65000 learn the same internet”. The controlling choice is “Set a higher local preference on routes learned through Border-B”. Evidence: “prefix from different providers the company wants all”.
Prepending modifies advertised AS paths to influence external inbound choices; it does not directly set the internal preferred egress. Context: “two border routers in as 65000 learn the same internet”. The controlling choice is “Set a higher local preference on routes learned through Border-B”. Evidence: “prefix from different providers the company wants all”.
Local preference is designed to express the preferred outbound exit within an autonomous system, and higher values are preferred. The value is distributed to iBGP peers in the local AS. For border routers 65000 learn, the decisive technical behavior is bgp localpref outbound, which this option supplies.

Question 7

After weight and local preference are equal, a router compares two otherwise comparable BGP paths. Path A has AS_PATH `64510 64520`, while Path B has `64530 64540 64550`. Which path is normally preferred at the AS-path step?

Path A because it has the shorter AS_PATH
Path B because the numerically highest AS wins
Neither; BGP ignores AS_PATH for eBGP routes
Path B because a longer AS_PATH is more specific

Correct Answer(s)

Rationale

The BGP best-path process normally prefers a shorter AS path when earlier, higher-priority attributes have not already decided the path. Two AS hops therefore beat three at this step.
BGP does not prefer a path merely because its AS numbers are numerically higher. Context: “after weight and local preference are equal a router compares”. The controlling choice is “Path A because it has the shorter AS_PATH”. Evidence: “two otherwise comparable bgp paths path a has”.
AS_PATH is a fundamental BGP path attribute and is part of normal best-path selection. Context: “after weight and local preference are equal a router compares”. The controlling choice is “Path A because it has the shorter AS_PATH”. Evidence: “two otherwise comparable bgp paths path a has”.
AS-path length is not prefix specificity; a longer AS sequence is normally less preferred, not more preferred. Context: “after weight and local preference are equal a router compares”. The controlling choice is “Path A because it has the shorter AS_PATH”. Evidence: “two otherwise comparable bgp paths path a has”.

Question 8

An enterprise receives two routes to the same prefix from the same neighboring autonomous system over two links. Earlier best-path attributes are equal. The provider sets MED 50 on link A and MED 150 on link B. Which path is normally preferred at the MED step?

Link B because the higher MED is preferred
Both links because MED is never considered by BGP
Link A because the lower MED is preferred
Link B because MED overrides weight and local preference

Correct Answer(s)

Rationale

MED preference is the opposite: lower values are normally preferred. Context: “an enterprise receives two routes to the same prefix from”. The controlling choice is “Link A because the lower MED is preferred”. Evidence: “the same neighboring autonomous system over two links”.
MED is a recognized BGP path attribute and can participate in best-path selection. Context: “an enterprise receives two routes to the same prefix from”. The controlling choice is “Link A because the lower MED is preferred”. Evidence: “the same neighboring autonomous system over two links”.
MED is a metric-like hint to the neighboring AS, and the lower value is normally preferred when the paths are eligible for MED comparison. A value of 50 therefore wins over 150.
MED is considered later than attributes such as weight and local preference; it does not automatically override them. Context: “an enterprise receives two routes to the same prefix from”. The controlling choice is “Link A because the lower MED is preferred”. Evidence: “the same neighboring autonomous system over two links”.

Question 9

A router has two BGP paths to the same prefix with equal weight, local preference, locally originated status, AS-path length, origin, and MED. One path is learned through eBGP and the other through iBGP. Which path is preferred next?

The eBGP-learned path
Both paths must be discarded as a loop
The iBGP-learned path
The path with the higher neighbor router ID

Correct Answer(s)

Rationale

With the earlier attributes tied, the normal BGP best-path process prefers an eBGP path over an iBGP path. That preference is evaluated before later tiebreakers such as router ID. Here, the bgp ebgp over ibgp decision is consistent with the scenario evidence around router has bgp paths.
Learning the same destination from eBGP and iBGP is normal and does not by itself indicate an AS loop. Context: “a router has two bgp paths to the same prefix”. The controlling choice is “The eBGP-learned path”. Evidence: “with equal weight local preference locally originated status”.
iBGP is not preferred over eBGP at this point in the standard Cisco best-path sequence. Context: “a router has two bgp paths to the same prefix”. The controlling choice is “The eBGP-learned path”. Evidence: “with equal weight local preference locally originated status”.
Router ID is a later tiebreaker and is not considered before the eBGP-versus-iBGP preference. Context: “a router has two bgp paths to the same prefix”. The controlling choice is “The eBGP-learned path”. Evidence: “with equal weight local preference locally originated status”.

Question 10

A BGP route is visible in the BGP table but is not installed as a usable route because its next hop cannot be reached through the routing table. Which issue should be corrected first?

Enable PBR on the loopback interface
Change the prefix length of the advertised network
Restore reachability to the BGP next-hop address
Increase the route’s MED

Correct Answer(s)

Rationale

PBR is not a substitute for resolving the BGP next hop in the routing and forwarding tables. Context: “a bgp route is visible in the bgp table but”. The controlling choice is “Restore reachability to the BGP next-hop address”. Evidence: “is not installed as a usable route because”.
The symptom concerns next-hop reachability for an already learned route, not the advertised prefix length. Context: “a bgp route is visible in the bgp table but”. The controlling choice is “Restore reachability to the BGP next-hop address”. Evidence: “is not installed as a usable route because”.
A BGP path with an inaccessible next hop cannot be used for forwarding. Correcting reachability to the next hop is therefore a prerequisite before later path preferences matter. Context: “a bgp route is visible in the bgp table but”. This answer directly implements “Restore reachability to the BGP next-hop address”. Evidence: “is not installed as a usable route because”.
Changing MED does not make an unreachable next hop reachable. Context: “a bgp route is visible in the bgp table but”. The controlling choice is “Restore reachability to the BGP next-hop address”. Evidence: “is not installed as a usable route because”.

Question 11

A border router should prefer provider A for a specific set of inbound BGP routes while leaving other received routes at the default local preference. Which approach best fits?

Apply `ip policy route-map` to the provider-facing interface
Apply an inbound route map to provider A that matches the target prefixes and sets a higher local preference
Set a higher MED on the enterprise’s outbound advertisements
Change the provider interface OSPF cost

Correct Answer(s)

Rationale

That command enables packet-level PBR for traffic entering the interface; it does not modify BGP path attributes on received routes. Context: “a border router should prefer provider a for a specific”. The controlling choice is “Apply an inbound route map to provider A that matches the target prefixes and sets a higher local preference”. Evidence: “set of inbound bgp routes while leaving other”.
An inbound route map can classify the selected routes as they are received and set local preference only for those routes. Other routes can fall through to a permit clause without the modified value.
MED sent outward influences a neighbor’s path selection and does not directly raise local preference on routes learned inbound. Context: “a border router should prefer provider a for a specific”. The controlling choice is “Apply an inbound route map to provider A that matches the target prefixes and sets a higher local preference”. Evidence: “set of inbound bgp routes while leaving other”.
The requirement is BGP policy on received routes, not an OSPF path-cost decision. Context: “a border router should prefer provider a for a specific”. The controlling choice is “Apply an inbound route map to provider A that matches the target prefixes and sets a higher local preference”. Evidence: “set of inbound bgp routes while leaving other”.

Question 12

An enterprise must ensure that only 203.0.113.0/24 is advertised to a directly connected eBGP neighbor. Which control most directly limits the outbound BGP prefixes?

Enable BPDU Guard on the provider-facing port
Apply an inbound PBR route map on the LAN interface
Increase the local preference of 203.0.113.0/24
Apply an outbound prefix list or route policy to that BGP neighbor

Correct Answer(s)

Rationale

BPDU Guard is a spanning-tree protection feature and has no role in BGP route filtering. Context: “an enterprise must ensure that only 203 0 113 0”. The controlling choice is “Apply an outbound prefix list or route policy to that BGP neighbor”. Evidence: “24 is advertised to a directly connected ebgp”.
PBR selects forwarding treatment for packets; it does not filter BGP route advertisements. Context: “an enterprise must ensure that only 203 0 113 0”. The controlling choice is “Apply an outbound prefix list or route policy to that BGP neighbor”. Evidence: “24 is advertised to a directly connected ebgp”.
Local preference influences local best-path selection and does not prevent other prefixes from being advertised. Context: “an enterprise must ensure that only 203 0 113 0”. The controlling choice is “Apply an outbound prefix list or route policy to that BGP neighbor”. Evidence: “24 is advertised to a directly connected ebgp”.
Neighbor-level outbound filtering is the direct control for deciding which BGP NLRI may be advertised. A prefix list or route map can permit the intended prefix and deny the rest.

Question 13

A customer eBGP neighbor is expected to send no more than 500 prefixes. The enterprise wants the session protected from an accidental full-table leak. Which neighbor control is most appropriate?

Use PBR to set the next hop to Null0
Enable route dampening on every prefix
Set the local preference to 500
Configure a maximum-prefix limit for the neighbor

Correct Answer(s)

Rationale

PBR acts on data packets and would not stop a peer from sending an excessive number of BGP routes. Context: “a customer ebgp neighbor is expected to send no more”. The controlling choice is “Configure a maximum-prefix limit for the neighbor”. Evidence: “than 500 prefixes the enterprise wants the session”.
Dampening targets instability or flapping behavior, not a simple maximum received-prefix count. Context: “a customer ebgp neighbor is expected to send no more”. The controlling choice is “Configure a maximum-prefix limit for the neighbor”. Evidence: “than 500 prefixes the enterprise wants the session”.
Local preference is a path-selection value, not a count limit on received prefixes. Context: “a customer ebgp neighbor is expected to send no more”. The controlling choice is “Configure a maximum-prefix limit for the neighbor”. Evidence: “than 500 prefixes the enterprise wants the session”.
The maximum-prefix feature can detect when a peer advertises more routes than the expected threshold and take configured protective action. It directly addresses accidental route-volume expansion. Context: “a customer ebgp neighbor is expected to send no more”. This answer directly implements “Configure a maximum-prefix limit for the neighbor”. Evidence: “than 500 prefixes the enterprise wants the session”.

Question 14

A route map adds a BGP community to selected outbound routes, but the neighbor never receives the community attribute. The routes themselves are advertised correctly. What configuration should be verified?

The interface has `ip policy route-map` configured
The neighbor is configured to send BGP communities
The neighbor has a lower MED
The interface has an HSRP group configured

Correct Answer(s)

Rationale

Packet PBR does not control whether BGP communities are included in route updates. Context: “a route map adds a bgp community to selected outbound”. The controlling choice is “The neighbor is configured to send BGP communities”. Evidence: “routes but the neighbor never receives the community”.
On Cisco BGP, adding a community to a route is not sufficient if community transmission to the neighbor is not enabled. The send-community setting controls propagation of that attribute. The route map adds bgp constraints make this the appropriate bgp send community outcome for the design.
MED values do not enable or disable transmission of the community attribute. Context: “a route map adds a bgp community to selected outbound”. The controlling choice is “The neighbor is configured to send BGP communities”. Evidence: “routes but the neighbor never receives the community”.
HSRP provides first-hop redundancy and is unrelated to BGP community propagation. Context: “a route map adds a bgp community to selected outbound”. The controlling choice is “The neighbor is configured to send BGP communities”. Evidence: “routes but the neighbor never receives the community”.

Question 15

An enterprise is multihomed and wants remote networks to view provider B as the less attractive inbound path for a particular advertised prefix. Which BGP technique is commonly used?

Lower the administrative distance of eBGP
Raise local preference on routes learned from provider B
Prepend the enterprise AS multiple times when advertising the prefix to provider B
Apply PBR to traffic arriving from provider B

Correct Answer(s)

Rationale

Administrative distance is local route-source preference and is not advertised to external networks. Context: “an enterprise is multihomed and wants remote networks to view”. The controlling choice is “Prepend the enterprise AS multiple times when advertising the prefix to provider B”. Evidence: “provider b as the less attractive inbound path”.
Local preference influences the enterprise’s outbound exit choice and is not propagated to remote autonomous systems. Context: “an enterprise is multihomed and wants remote networks to view”. The controlling choice is “Prepend the enterprise AS multiple times when advertising the prefix to provider B”. Evidence: “provider b as the less attractive inbound path”.
AS-path prepending lengthens the advertised path through provider B. Remote BGP speakers that compare otherwise similar paths may then prefer the shorter path through the other provider. Context: “an enterprise is multihomed and wants remote networks to view”. This answer directly implements “Prepend the enterprise AS multiple times when advertising the prefix to provider B”. Evidence: “provider b as the less attractive inbound path”.
PBR affects packets after they arrive and does not alter the AS path that remote networks see. Context: “an enterprise is multihomed and wants remote networks to view”. The controlling choice is “Prepend the enterprise AS multiple times when advertising the prefix to provider B”. Evidence: “provider b as the less attractive inbound path”.

Question 16

An outbound BGP route map contains only sequence 10, which permits one prefix and sets a community. After the route map is applied to the neighbor, all other prefixes disappear from the advertisements. Why?

Routes that do not match a permitted route-map sequence are denied by the implicit end of the policy
Local preference defaults to zero for unmatched routes
The eBGP session changes to iBGP when a route map is applied
BGP automatically converts unmatched routes to static routes

Correct Answer(s)

Rationale

A route map used for BGP policy has an implicit deny when no sequence permits a route. Adding an appropriate later permit sequence is required when unmatched routes should continue to be advertised.
Cisco BGP local preference normally defaults to 100, and this symptom is caused by policy filtering rather than a zero value. Context: “an outbound bgp route map contains only sequence 10 which”. The controlling choice is “Routes that do not match a permitted route-map sequence are denied by the implicit end of the policy”. Evidence: “permits one prefix and sets a community after”.
Policy application does not change the autonomous-system relationship between peers. Context: “an outbound bgp route map contains only sequence 10 which”. The controlling choice is “Routes that do not match a permitted route-map sequence are denied by the implicit end of the policy”. Evidence: “permits one prefix and sets a community after”.
BGP policy does not transform unmatched routes into static routes. Context: “an outbound bgp route map contains only sequence 10 which”. The controlling choice is “Routes that do not match a permitted route-map sequence are denied by the implicit end of the policy”. Evidence: “permits one prefix and sets a community after”.

Question 17

Traffic entering GigabitEthernet1 should use a policy route map named BRANCH-POLICY. The route map already matches the desired source subnet and sets a next hop. Which configuration attaches the policy to incoming packets on that interface?

Configure `ip local policy route-map BRANCH-POLICY` globally
Configure `ip policy route-map BRANCH-POLICY` under GigabitEthernet1
Configure `neighbor BRANCH-POLICY route-map in` under BGP
Configure `service-policy input BRANCH-POLICY` on the interface

Correct Answer(s)

Rationale

Local policy routing applies to packets generated by the router itself, not ordinary transit packets arriving on GigabitEthernet1. Context: “traffic entering gigabitethernet1 should use a policy route map named”. The controlling choice is “Configure `ip policy route-map BRANCH-POLICY` under GigabitEthernet1”. Evidence: “branch policy the route map already matches the”.
The interface-level `ip policy route-map` command applies PBR to packets arriving on that interface. The route map then evaluates its match and set clauses for those packets. Context: “traffic entering gigabitethernet1 should use a policy route map named”. This answer directly implements “Configure `ip policy route-map BRANCH-POLICY` under GigabitEthernet1”. Evidence: “branch policy the route map already matches the”.
A BGP neighbor route map processes routing updates, not data-plane packets entering the interface. Context: “traffic entering gigabitethernet1 should use a policy route map named”. The controlling choice is “Configure `ip policy route-map BRANCH-POLICY` under GigabitEthernet1”. Evidence: “branch policy the route map already matches the”.
A service policy is a QoS construct and does not attach an IP policy-routing route map. Context: “traffic entering gigabitethernet1 should use a policy route map named”. The controlling choice is “Configure `ip policy route-map BRANCH-POLICY` under GigabitEthernet1”. Evidence: “branch policy the route map already matches the”.

Question 18

Finance traffic from 10.20.0.0/16 should exit through ISP-B while all other users follow the normal routing table. Which PBR design is most appropriate?

Match the Finance source addresses in a route map and set ISP-B as the next hop
Place Finance and all other users in the same static default route
Increase the OSPF cost only for Finance hosts
Set BGP local preference on the user VLAN interface

Correct Answer(s)

Rationale

PBR can make source-sensitive forwarding decisions by matching an ACL or other criteria and setting a different next hop for the selected packets. Unmatched traffic can continue to normal destination routing.
A single default route cannot create different egress behavior based on source address. Context: “finance traffic from 10 20 0 0 16 should exit”. The controlling choice is “Match the Finance source addresses in a route map and set ISP-B as the next hop”. Evidence: “through isp b while all other users follow”.
OSPF cost is a routing-topology metric and does not vary forwarding based on the source host subnet in this manner. Context: “finance traffic from 10 20 0 0 16 should exit”. The controlling choice is “Match the Finance source addresses in a route map and set ISP-B as the next hop”. Evidence: “through isp b while all other users follow”.
Local preference is a BGP route attribute, not an interface-level source classifier. Context: “finance traffic from 10 20 0 0 16 should exit”. The controlling choice is “Match the Finance source addresses in a route map and set ISP-B as the next hop”. Evidence: “through isp b while all other users follow”.

Question 19

SNMP traps generated by the router itself must leave through a management next hop that differs from the ordinary routing-table choice. Transit traffic must remain unaffected. Which feature fits?

Configure a BGP outbound prefix list
Raise the HSRP priority on the management VLAN
Apply `ip policy route-map` to every transit interface
Use `ip local policy route-map` for locally generated packets

Correct Answer(s)

Rationale

A prefix list filters routing advertisements and does not steer locally generated SNMP packets. Context: “snmp traps generated by the router itself must leave through”. The controlling choice is “Use `ip local policy route-map` for locally generated packets”. Evidence: “a management next hop that differs from the”.
HSRP priority changes first-hop active-router selection and does not policy-route traffic generated by this router. Context: “snmp traps generated by the router itself must leave through”. The controlling choice is “Use `ip local policy route-map` for locally generated packets”. Evidence: “a management next hop that differs from the”.
Interface PBR affects packets entering those interfaces and is broader than the router-generated-only requirement. Context: “snmp traps generated by the router itself must leave through”. The controlling choice is “Use `ip local policy route-map` for locally generated packets”. Evidence: “a management next hop that differs from the”.
Local policy routing subjects packets originated by the device to a route map while leaving transit traffic under ordinary forwarding unless other PBR is configured. That scope matches the requirement. For snmp traps generated router, the decisive technical behavior is pbr local generated, which this option supplies.

Question 20

A PBR route map is attached to an interface. A packet does not match any permit sequence in the route map. What normally happens to that packet?

It is always dropped by the route-map implicit deny
It is sent to the first eBGP neighbor regardless of destination
It is forwarded according to the normal destination-based routing table
It is flooded out all Layer 3 interfaces

Correct Answer(s)

Rationale

For PBR, a packet that is not policy-routed continues through normal routing; the route-map behavior is not equivalent to an ACL drop of the data packet. Context: “a pbr route map is attached to an interface a”. The controlling choice is “It is forwarded according to the normal destination-based routing table”. Evidence: “packet does not match any permit sequence in”.
PBR does not default unmatched packets to a BGP neighbor. Context: “a pbr route map is attached to an interface a”. The controlling choice is “It is forwarded according to the normal destination-based routing table”. Evidence: “packet does not match any permit sequence in”.
PBR applies alternate forwarding only when a policy sequence successfully matches and provides usable treatment. Traffic not policy-routed falls back to ordinary destination-based routing rather than being automatically discarded.
Routers do not flood unmatched IP packets in this way; normal routing lookup still applies. Context: “a pbr route map is attached to an interface a”. The controlling choice is “It is forwarded according to the normal destination-based routing table”. Evidence: “packet does not match any permit sequence in”.

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