300-410 IP SLA — Timed 15 Questions

Question 1

A network engineer is troubleshooting a site-to-site VPN that intermittently drops. The engineer configured IP SLA 10 to track reachability of the remote LAN gateway (10.1.2.1) using ICMP echo probes every 5 seconds. The IP SLA is used in a static route to influence failover. The engineer notices that the IP SLA state shows 'Active' but the tracked route is not installed. What is the most likely cause?

Accepted Answer

The track object is configured with 'ip sla 10 reachability' but the static route references the track object incorrectly.. The IP SLA is active, but the tracked object might not be configured correctly to react to the IP SLA state. The issue is that the track object is not linked to the IP SLA or the threshold is misconfigured.

Answer

The IP SLA probe is sending packets to the wrong destination IP.

Answer

The IP SLA probe frequency is too high, causing the router to ignore the results.

Answer

The remote gateway is not responding to ICMP echo requests due to firewall rules.

Question 2

An engineer configured IP SLA 20 to monitor the reachability of a next-hop router (192.168.1.1) using UDP jitter probes. The goal is to use the IP SLA with a track object to influence EIGRP route selection. However, the EIGRP route is not being affected by the IP SLA state. The engineer verifies that the IP SLA is 'Active' and the track object shows 'Up'. What is the most likely misconfiguration?

Accepted Answer

The track object is not configured to influence the EIGRP route; EIGRP does not support direct tracking of IP SLA for route metrics.. EIGRP does not natively react to IP SLA track objects unless the route is redistributed or a static route with tracking is used. The engineer likely expected EIGRP to automatically adjust metric based on IP SLA, which is not supported.

Answer

The IP SLA probe type (UDP jitter) is not supported for tracking EIGRP routes.

Answer

The EIGRP route has a higher administrative distance than the tracked route.

Answer

The IP SLA threshold is set too low, causing flapping.

Question 3

A network engineer configured IP SLA 30 to monitor the reachability of a server (10.10.10.10) using ICMP echo probes. The IP SLA is linked to a track object that is used in a static default route. The engineer notices that the IP SLA state is 'Active', but the static route is not present in the routing table. The track object shows 'Up'. What should the engineer check first?

Accepted Answer

Verify that the static route includes the 'track' keyword and references the correct track object number.. If the track object is up and the static route is not installed, the issue is likely that the static route configuration does not properly reference the track object, or the route is being overridden by another route with lower administrative distance.

Answer

Check if the server is responding to ICMP echo requests.

Answer

Ensure the IP SLA probe is configured with a timeout value less than the frequency.

Answer

Reboot the router to clear any routing table inconsistencies.

Question 4

An engineer configured IP SLA 40 with a UDP echo probe to monitor a remote server port 80. The IP SLA is used in a track object for a backup static route. The engineer observes that the IP SLA state is 'Timeout' even though the server is reachable via ping from the router. What is the most likely cause?

Accepted Answer

The server is not running a UDP service on port 80; HTTP uses TCP, so the UDP probe will fail.. UDP echo probes require a service listening on the specified port. If the server does not have a UDP service on port 80 (HTTP uses TCP), the probe will timeout.

Answer

The router's firewall is blocking UDP packets to the server.

Answer

The IP SLA frequency is set too high, causing the router to miss responses.

Answer

The track object is misconfigured with the wrong IP SLA number.

Question 5

A network engineer configured IP SLA 50 to monitor a remote router's loopback (5.5.5.5) using ICMP echo. The IP SLA is linked to a track object that is used in a PBR (policy-based routing) route-map. The engineer notices that the PBR is not applying the alternate path when the IP SLA goes down. The track object shows 'Down'. What is the most likely misconfiguration?

Accepted Answer

The route-map is missing the 'set ip next-hop verify-availability' command with the track object.. PBR with set ip next-hop verify-availability requires the track object to be referenced correctly in the route-map. If the route-map uses 'set ip next-hop verify-availability' but does not include the track keyword, PBR will not react to the IP SLA state.

Answer

The IP SLA probe is using the wrong source interface.

Answer

The track object is configured with a delay that prevents immediate reaction.

Answer

The PBR is applied to the wrong interface.

Question 6

An engineer configured IP SLA 60 to monitor the reachability of a WAN link's next-hop (203.0.113.1) using ICMP echo. The IP SLA is used in a track object for a floating static route. The engineer notices that the primary route (EIGRP) is present, but the floating static route is not installed when the primary fails. The track object shows 'Down' after the primary fails. What should the engineer check?

Accepted Answer

Verify that the static route's administrative distance is higher than the EIGRP route (e.g., 170 vs 90).. A floating static route with tracking requires the administrative distance to be higher than the primary route. If the AD is lower or equal, the static route will not be installed as a backup. Also, the track object must be correctly referenced.

Answer

Check if the IP SLA probe is configured with a timeout greater than the frequency.

Answer

Ensure the primary route is removed from the routing table before the static route is installed.

Answer

Reboot the router to clear the routing table.

Question 7

A network engineer configured IP SLA 70 to monitor a remote site's LAN gateway (172.16.1.1) using ICMP echo. The IP SLA is linked to a track object that is used in a static route for a backup link. The engineer notices that the IP SLA state is 'Active', but the backup static route is installed in the routing table even when the primary route is available. What is the most likely cause?

Accepted Answer

The static route is configured without the 'track' keyword, so it is always installed regardless of the IP SLA state.. If the backup static route is installed while the primary route is available, the static route likely has a lower administrative distance than the primary route, or the track object is not being used correctly (e.g., the static route does not have the 'track' keyword).

Answer

The IP SLA probe is failing intermittently, causing the track object to flap.

Answer

The primary route has a higher administrative distance than the static route.

Answer

The track object is configured with a delay that causes the static route to be installed prematurely.

Question 8

An engineer configured IP SLA 80 to monitor a remote server (192.168.100.100) using ICMP echo. The IP SLA is used in a track object for a static route. The engineer notices that the IP SLA state is 'Active', but the track object shows 'Down'. What is the most likely cause?

Accepted Answer

The track object is configured with a 'delay up' timer that has not yet expired.. The track object can be configured with a threshold (e.g., 'threshold' or 'delay') that causes it to remain 'Down' even if the IP SLA is 'Active'. For example, if the track object has a 'delay up' timer, it will not transition to 'Up' immediately.

Answer

The IP SLA probe is using a different source IP than expected.

Answer

The track object is referencing the wrong IP SLA number.

Answer

The router's routing table is full, preventing the track object from updating.

Question 9

A network engineer configured IP SLA 90 to monitor a remote router's loopback (10.0.0.1) using ICMP echo. The IP SLA is linked to a track object that is used in a static route. The engineer notices that the IP SLA state is 'Active', but the static route is not installed. The track object shows 'Up'. The engineer checks the routing table and sees a different route to the same destination with a lower administrative distance. What should the engineer do to ensure the IP SLA-tracked route is used when the primary fails?

Accepted Answer

Remove the primary route from the routing table.. If a route with a lower AD exists, the IP SLA-tracked route will not be installed unless the primary route is removed. The engineer must ensure the tracked route has a higher AD than the primary route, or remove the primary route.

Answer

Increase the administrative distance of the IP SLA-tracked static route to be higher than the primary route.

Answer

Change the IP SLA probe to use UDP instead of ICMP.

Answer

Add a 'set metric' command to the IP SLA configuration.

Question 10

A network engineer runs the following command on Router R1:

R1# show ip sla statistics 1

Round Trip Time (RTT) for Index 1
   Latest RTT: 200 ms
   Latest RTT (milliseconds): 200
   Latest RTT (microseconds): 200000
   Number of successes: 50
   Number of failures: 10
   Operation time to live: Forever
   Output: Over threshold

Based on this output, which statement is correct?

Accepted Answer

The latest RTT has exceeded the configured threshold value.. The 'Output: Over threshold' line indicates that the latest RTT exceeded the configured threshold. The number of failures (10) suggests some probes failed, but the key clue is the threshold violation. This does not necessarily mean the operation is down; it means a threshold event occurred.

Answer

The IP SLA operation has failed due to a timeout.

Answer

The IP SLA operation is not reachable and has been disabled.

Answer

The IP SLA responder is not configured on the target device.

Question 11

A network engineer runs the following command on Router R1:

R1# show ip sla summary

IPSLAs Latest Operation Summary

Codes: * active, ^ inactive, ~ pending

ID       Type            Destination       Stats          Return Code      Last
1        icmp-echo       192.168.1.1       RTT=50ms       OK               1s ago
2        icmp-echo       192.168.1.2       RTT=2000ms     Over threshold   2s ago
3        icmp-echo       192.168.1.3       RTT=100ms      OK               3s ago

Based on this output, which statement is correct?

Accepted Answer

IP SLA operation 2 is experiencing high latency, exceeding the configured threshold.. The 'Return Code' column shows 'Over threshold' for ID 2, meaning the RTT exceeded the configured threshold. The other operations are OK. This output does not indicate failure or timeout unless the return code says so.

Answer

IP SLA operation 2 has failed because the destination is unreachable.

Answer

IP SLA operation 1 is not active because it shows 'OK'.

Answer

IP SLA operation 3 has a pending status.

Question 12

A network engineer runs the following command on Router R1:

R1# show ip sla configuration 1

IP SLAs Infrastructure Engine-II
Entry number: 1
Owner: 
Tag: 
Type of operation to perform: icmp-echo
Target address: 192.168.1.1
Source address: 0.0.0.0
Source interface: none
Type Of Service parameter: 0
Verify data: No
Operation timeout (milliseconds): 5000
Request size (ARR data block): 28
Threshold (milliseconds): 100
Frequency (seconds): 10
Life (seconds): Forever
Ageout (seconds): 0

Based on this output, what is the primary problem with this IP SLA configuration?

Accepted Answer

The source address is set to 0.0.0.0, which may cause the probe to fail if the router does not have a valid route.. The source address is 0.0.0.0 and no source interface is configured. This means the router will use the outgoing interface's IP address, which might not be routable or expected. However, the key clue is that the threshold is set to 100 ms, but the operation timeout is 5000 ms. If the RTT exceeds 100 ms, the operation will report 'Over threshold' but not necessarily fail. The question focuses on configuration issues; the source address being 0.0.0.0 is a common misconfiguration that can cause problems if the router cannot reach the target.

Answer

The threshold value is too low, causing frequent threshold violations.

Answer

The frequency is set to 10 seconds, which is too fast for accurate measurements.

Answer

The operation timeout is too high, causing delays in failure detection.

Question 13

A network engineer runs the following command on Router R1:

R1# show ip sla statistics 2

Round Trip Time (RTT) for Index 2
   Latest RTT: No connection
   Latest RTT (milliseconds): No connection
   Latest RTT (microseconds): No connection
   Number of successes: 0
   Number of failures: 100
   Operation time to live: Forever
   Output: No connection

Based on this output, which statement is correct?

Accepted Answer

The target device is not responding to ICMP echo requests, or there is a routing problem.. The output shows 'No connection' for RTT and 'Output: No connection'. This indicates that the IP SLA operation cannot reach the target. The 100 failures confirm this. This is a clear sign of a connectivity issue.

Answer

The IP SLA operation is working correctly but the RTT is too high to measure.

Answer

The IP SLA operation has been manually disabled.

Answer

The IP SLA responder is misconfigured on the source router.

Question 14

A network engineer runs the following command on Router R1:

R1# show ip sla statistics 3

Round Trip Time (RTT) for Index 3
   Latest RTT: 150 ms
   Latest RTT (milliseconds): 150
   Latest RTT (microseconds): 150000
   Number of successes: 80
   Number of failures: 20
   Operation time to live: Forever
   Output: OK

R1# show track 1
Track 1
  IP SLA 3 reachability
  Reachability is Up
    2 changes, last change 00:00:10
  Latest operation return code: OK
  Latest RTT (milliseconds): 150
  Tracked by:
    ip route 0.0.0.0 0.0.0.0 192.168.1.1 track 1

Based on this output, which statement is correct?

Accepted Answer

The IP SLA operation is considered reachable, and the tracked static route is active.. The track shows 'Reachability is Up' based on IP SLA 3. The IP SLA statistics show successes and failures, but the latest return code is OK, so the track is up. This means the static route is active. The failures (20) indicate some probes failed, but the track still considers it reachable because the threshold for reachability is likely based on a percentage or consecutive failures.

Answer

The static route is removed because the IP SLA operation has failures.

Answer

The IP SLA operation has a 20% failure rate, so the track should be down.

Answer

The IP SLA operation is using a wrong source address.

Question 15

A network engineer runs the following command on Router R1:

R1# show ip sla statistics 4

Round Trip Time (RTT) for Index 4
   Latest RTT: 300 ms
   Latest RTT (milliseconds): 300
   Latest RTT (microseconds): 300000
   Number of successes: 45
   Number of failures: 55
   Operation time to live: Forever
   Output: Over threshold

R1# show track 2
Track 2
  IP SLA 4 reachability
  Reachability is Down
    5 changes, last change 00:00:05
  Latest operation return code: Over threshold
  Latest RTT (milliseconds): 300
  Tracked by:
    ip route 0.0.0.0 0.0.0.0 192.168.2.1 track 2

Based on this output, which statement is correct?

Accepted Answer

The IP SLA threshold has been exceeded, causing the track to go down and the static route to be removed.. The track shows 'Down' because the IP SLA return code is 'Over threshold'. This means the threshold was exceeded, and the track has brought down the static route. The failures (55) are high, but the key is that the track is down due to the threshold violation.

Answer

The IP SLA operation is failing because the target is unreachable.

Answer

The tracked static route is active because the IP SLA has successes.

Answer

The IP SLA operation has a 55% failure rate, but the track is still up.