F5 301b 問題集

質問 1：
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Refer to the exhibits.
A virtual server has been configured for SSL offload on a single-arm network. On average, the virtual server will be handling 100,000 connections, with a peak of 130,000 connections. Between the virtual server and the web servers there is a single reverse proxy to provide site caching. The proxy is configured to perform source IP persistence before contacting the web servers. The site is logging users out immediately after logging them in.
What should the LTM Specialist do to resolve this issue?
A. Change the virtual server server-side TCP profile to tcp-lan-optimized.
B. Create an iRule to add client IP persistence to a SNAT pool member.
C. Configure the virtual server HTTP profile to insert an X-Forwarded-For header.
D. Add a source address persistence profile to the virtual server.
正解：B

質問 2：
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-- Exhibit --
Refer to the exhibits.
An LTM Specialist is troubleshooting an issue with one of the virtual servers on an LTM device, and all requests are receiving errors. Testing directly against the server generates no errors. The LTM Specialist has captured the request and response on both client and server sides of the LTM device.
What should the LTM Specialist do to fix this issue?
A. Assign OneConnect profile to the virtual server.
B. Remove "header-erase Host" in http profile.
C. Configure SNAT Automap on the virtual server.
D. Set "redirect-rewrite" to "selective" in http profile.
正解：B

質問 3：
While investigating the cause of a device failover, an LTM Specialist discovers the following events in /var/log/ltm:
01010029:5: Clock advanced by 518 ticks 01010029:5: Clock advanced by 505 ticks 01010029:5: Clock advanced by 590 ticks 01010029:5: Clock advanced by 568 ticks 01010029:5: Clock advanced by 1681 ticks 01010029:5: Clock advanced by 6584 ticks 01140029:5: HA daemon_heartbeat tmm fails action is failover and restart. 010c0026:5: Failover condition, active attempting to go standby.
Which issue caused the failover?
A. HA missing heartbeat packets
B. VLAN Fail-safe heartbeats
C. NTP being out of sync
D. TMM being descheduled
正解：D

質問 4：
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Refer to the exhibit.
An LTM Specialist has created a virtual server to load balance traffic to a pool of HTTPS servers. The servers use client certificates for user authentication. The virtual server has clientssl, serverssl, and http profiles enabled. Clients are unable to connect to the application through the virtual server. Clients are able to connect to the application servers directly.
What is the root cause of the problem?
A. The application server does NOT see the client certificate due to SSL offload.
B. The application server does NOT support 2048-bit keys.
C. The clientssl profile is NOT set to require a client certificate.
D. The LTM device does NOT trust the issuing CA of the client certificate.
正解：A

質問 5：
An LTM Specialist is troubleshooting an issue with a new virtual server. When connecting through the virtual server, clients receive the message "Unable to connect" in the browser, although connections directly to the pool member show the application is functioning correctly. The LTM configuration is:
ltm virtual /Common/vs_https { destination /Common/10.10.1.110:443 ip-protocol udp mask 255.255.255.255 pool /Common/pool_https profiles { /Common/udp { } } translate-address enabled translate-port enabled vlans-disabled }
ltm pool /Common/pool_https { members { /Common/172.16.20.1:443 { address 172.16.20.1 } } }
How should the LTM Specialist resolve this issue?
A. Remove an HTTP monitor from the pool.
B. Select the correct protocol for the virtual server.
C. Enable the pool member on the correct VLAN.
D. Add an HTTP profile to the virtual server.
正解：B

質問 6：
Which command will identify the active LTM device currently handling client traffic?
A. b ha table show
B. tmsh show /sys ha-status all-properties
C. tmsh show /cm traffic-group
D. tmsh run /sys failover standby
E. tmsh list /sys ha-status
正解：C

質問 7：
An application owner claims an LTM device is delaying delivery of an HTTP application. The LTM device has two VLANs, an internal and an external. The application servers reside on the internal VLAN. The virtual server and clients reside on the external VLAN.
With appropriate filters applied, which solution is most efficient for obtaining packet captures in order to investigate the claim of delayed delivery?
A. one capture on the external interface
B. one capture on interface 0.0
C. one capture on the internal interface
D. one capture on the management interface
正解：B

質問 8：
Windows PC clients are connecting to a virtual server over a high-speed, low-latency network with no packet loss.
Which built-in client-side TCP profile provides the highest throughput for HTTP downloads?
A. tcp-legacy
B. tcp-lan-optimized
C. tcp-wan-optimized
D. tcp
正解：B

質問 9：
An LTM device has a virtual server configured as a Performance Layer 4 virtual listening on
0.0.0.0:0 to perform routing of packets to an upstream router. The client machine at IP address 192.168.0.4 is attempting to contact a host upstream of the LTM device on IP address 10.0.0.99.
The network flow is asymmetrical, and the following TCP capture displays:
# tcpdump -nnni 0.0 'host 192.168.0.4 and host 10.0.0.99'
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on 0.0, link-type EN10MB (Ethernet), capture size 96 bytes
05:07:55.499954 IP 192.168.0.4.35345 > 10.0.0.99.443: S 3205656213:3205656213(0) ack 3267995082 win 1480
05:07:55.499983 IP 10.0.0.99.443 > 192.168.0.4.35345: R 1:1(0) ack 1 win 0
05:07:56.499960 IP 192.168.0.4.35345 > 10.0.0.99.443: S 3205656213:3205656213(0) ack 3267995082 win 1480
05:07:56.499990 IP 10.0.0.99.443 > 192.168.0.4.35345: R 1:1(0) ack 1 win 0
4 packets captured
Which option within the fastL4 profile needs to be enabled by the LTM Specialist to prevent the LTM device from rejecting the flow?
A. Reset on Timeout
B. Loose Close
C. Generate Initial Sequence Number
D. Loose Initiation
正解：D