代码：
string ipStr = "192.168.1.10";
Ping p1 = new Ping();
PingReply reply = p1.Send(ip);
reply返回的状态：
public enum IPStatus
{
//
// 摘要:
// The ICMP echo request succeeded; an ICMP echo reply was received. When you get
// this status code, the other System.Net.NetworkInformation.PingReply properties
// contain valid data.
Success = 0,
//
// 摘要:
// The ICMP echo request failed because the network that contains the destination
// computer is not reachable.
DestinationNetworkUnreachable = 11002,
//
// 摘要:
// The ICMP echo request failed because the destination computer is not reachable.
DestinationHostUnreachable = 11003,
//
// 摘要:
// The ICMP echo request failed because the destination computer that is specified
// in an ICMP echo message is not reachable, because it does not support the packet's
// protocol.
DestinationProtocolUnreachable = 11004,
//
// 摘要:
// The ICMP echo request failed because the port on the destination computer is
// not available.
DestinationPortUnreachable = 11005,
//
// 摘要:
// The ICMP echo request failed because contact with the destination computer is
// administratively prohibited.
DestinationProhibited = 11004,
//
// 摘要:
// The ICMP echo request failed because of insufficient network resources.
NoResources = 11006,
//
// 摘要:
// The ICMP echo request failed because it contains an invalid option.
BadOption = 11007,
//
// 摘要:
// The ICMP echo request failed because of a hardware error.
HardwareError = 11008,
//
// 摘要:
// The ICMP echo request failed because the packet containing the request is larger
// than the maximum transmission unit (MTU) of a node (router or gateway) located
// between the source and destination. The MTU defines the maximum size of a transmittable
// packet.
PacketTooBig = 11009,
//
// 摘要:
// The ICMP echo Reply was not received within the allotted time. The default time
// allowed for replies is 5 seconds. You can change this value using the Overload:System.Net.NetworkInformation.Ping.Send
// or Overload:System.Net.NetworkInformation.Ping.SendAsync methods that take a
// timeout parameter.
TimedOut = 11010,
//
// 摘要:
// The ICMP echo request failed because there is no valid route between the source
// and destination computers.
BadRoute = 11012,
//
// 摘要:
// The ICMP echo request failed because its Time to Live (TTL) value reached zero,
// causing the forwarding node (router or gateway) to discard the packet.
TtlExpired = 11013,
//
// 摘要:
// The ICMP echo request failed because the packet was divided into fragments for
// transmission and all of the fragments were not received within the time allotted
// for reassembly. RFC 2460 (available at www.ietf.org) specifies 60 seconds as
// the time limit within which all packet fragments must be received.
TtlReassemblyTimeExceeded = 11014,
//
// 摘要:
// The ICMP echo request failed because a node (router or gateway) encountered problems
// while processing the packet header. This is the status if, for example, the header
// contains invalid field data or an unrecognized option.
ParameterProblem = 11015,
//
// 摘要:
// The ICMP echo request failed because the packet was discarded. This occurs when
// the source computer's output queue has insufficient storage space, or when packets
// arrive at the destination too quickly to be processed.
SourceQuench = 11016,
//
// 摘要:
// The ICMP echo request failed because the destination IP address cannot receive
// ICMP echo requests or should never appear in the destination address field of
// any IP datagram. For example, calling Overload:System.Net.NetworkInformation.Ping.Send
// and specifying IP address "000.0.0.0" returns this status.
BadDestination = 11018,
//
// 摘要:
// The ICMP echo request failed because the destination computer that is specified
// in an ICMP echo message is not reachable; the exact cause of problem is unknown.
DestinationUnreachable = 11040,
//
// 摘要:
// The ICMP echo request failed because its Time to Live (TTL) value reached zero,
// causing the forwarding node (router or gateway) to discard the packet.
TimeExceeded = 11041,
//
// 摘要:
// The ICMP echo request failed because the header is invalid.
BadHeader = 11042,
//
// 摘要:
// The ICMP echo request failed because the Next Header field does not contain a
// recognized value. The Next Header field indicates the extension header type (if
// present) or the protocol above the IP layer, for example, TCP or UDP.
UnrecognizedNextHeader = 11043,
//
// 摘要:
// The ICMP echo request failed because of an ICMP protocol error.
IcmpError = 11044,
//
// 摘要:
// The ICMP echo request failed because the source address and destination address
// that are specified in an ICMP echo message are not in the same scope. This is
// typically caused by a router forwarding a packet using an interface that is outside
// the scope of the source address. Address scopes (link-local, site-local, and
// global scope) determine where on the network an address is valid.
DestinationScopeMismatch = 11045,
//
// 摘要:
// The ICMP echo request failed for an unknown reason.
Unknown = -1
}