Time to ping resolve PTR record

Anybody can explain me why windows ping program took more than 11 seconds to discovery the PTR
record does not exist for specified IP address, but nslookup answer immediatelly? There is no
network latency, DNS service running on same machine. Load of server is minimal, on command
repeating got similar results. Windows 2003. Both command run just after DNS cache was flushed to
achieve same conditions:

c:\>ptime ping -a -n 1 10.12.34.177

ptime 1.0 for Win32, Freeware - http://www.pc-tools.net/
Copyright(C) 2002, Jem Berkes <>

=== ping -a -n 1 10.12.34.177 ===

Pinging 10.12.34.177 with 32 bytes of data:

Reply from 10.12.34.177: bytes=32 time<1ms TTL=64

Ping statistics for 10.12.34.177:
Packets: Sent = 1, Received = 1, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 0ms, Maximum = 0ms, Average = 0ms

Execution time: 11.504 s

--------------------------------------------------------------

c:\>ptime nslookup -type=ptr 10.12.34.177

ptime 1.0 for Win32, Freeware - http://www.pc-tools.net/
Copyright(C) 2002, Jem Berkes <>

=== nslookup -type=ptr 10.12.34.177 ===
*** Can't find server name for address 10.12.49.251: Non-existent domain
Server: UnKnown
Address: 10.12.49.251

*** UnKnown can't find 177.34.12.10.in-addr.arpa.: Non-existent domain

Execution time: 0.313 s