Lost 1 packet when Query F5 DNS

Hi guy

We have configuration F5 DNS. But After we were config complete, We have test, >> we see that:

When nslookup domain name: F5 DNS lost 1 packet first, I dont understand.

When we ping F5 DNS : IP listener: all erverthing ok.

DNS at my PC: I have setting manual : 10.10.10.2 ( IP listenser F5 DNS)

Please help me.

C:\Users\T440s>nslookup

DNS request timeout

timeout was 2 seconds

Default Server: UnKnown

Address: 10.10.10.2

> abc.com.vn

Server: UnKnown

Address: 10.10.10.2

Non-authoritative answer:

DNS request timed out.

  timeout was 2 seconds.

Name:  abc.com.vn

Address: 123.124.123.12

C:\Users\T440s>ping 10.10.10.2

Pinging 10.10.10.2 with 32 bytes of data:

Reply from 10.10.10.2 bytes=32 time=48ms TTL=51  

Reply from 10.10.10.2 bytes=32 time=48ms TTL=51

Reply from 10.10.10.2 bytes=32 time=48ms TTL=51

Reply from 10.10.10.2 bytes=32 time=48ms TTL=51

Ping statistics for 10.10.10.2:

  Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),

Approximate round trip times in milli-seconds:

  Minimum = 46ms, Maximum = 50ms, Average = 48ms