Operating System Microsoft Windows 2000 tcp/ip implementation Details
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- TCP/IP Troubleshooting Tools and Strategies
- IPConfig Tool
- Ping Tool
DNS Resolver Cache ServiceWindows 2000 includes a caching DNS resolver service, which is enabled by default. For troubleshooting purposes, this service can be viewed, stopped, and started like any other Windows service. The caching resolver reduces DNS network traffic and speeds name resolution by providing a local cache for DNS queries. Name query responses are cached for the TTL specified in the response (not to exceed the value specified in the MaxCacheEntryTtlLimit parameter), and future queries are answered from the cache, when possible. One interesting feature of the DNS Resolver Cache Service is that it supports negative caching. For example, if a query is made to a DNS server for a given host name and the response is negative, succeeding queries for the same name are answered (negatively) from the cache for NegativeCacheTime seconds (the default is 300). Another example of negative caching is that if all DNS servers are queried and none are available, for NetFailureCacheTime seconds (the default is 30) all succeeding name queries fail instantly, instead of timing out. This feature can save time for services that query the DNS during the boot process, especially when the client is booted from the network. The DNS Resolver Cache Service has a number of other adjustable registry parameters, which are documented in Appendix C. When troubleshooting any problem, it is helpful to use a logical approach. Some questions to ask are:
Troubleshooting a problem from the bottom up is often a good way to isolate the problem quickly. The tools listed below are organized for this approach. IPConfig ToolIPConfig is a command-line utility that prints out the TCP/IP-related configuration of a host. When used with the /all switch, it produces a detailed configuration report for all interfaces, including any configured serial ports (RAS). Output can be redirected to a file and pasted into other documents: C:\>ipconfig /all Windows 2000 IP configuration: Host Name . . . . . . . . . . . . : DAVEMAC2 Primary DNS Suffix . . . . . . . : mytest.microsoft.com Node Type . . . . . . . . . . . . : Hybrid IP Routing Enabled. . . . . . . . : No WINS Proxy Enabled. . . . . . . . : No DNS Suffix Search List. . . . . . : microsoft.com Ethernet adapter Local Area Connection 2: Connection-specific DNS Suffix . : Description . . . . . . . . . . . : 3Com EtherLink III EISA (3C579-TP) Physical Address. . . . . . . . . : 00-20-AF-1D-2B-91 DHCP Enabled. . . . . . . . . . . : No Autoconfiguration Enabled . . . . : Yes IP Address. . . . . . . . . . . . : 10.57.8.190 Subnet Mask . . . . . . . . . . . : 255.255.255.0 Default Gateway . . . . . . . . . : DNS Servers . . . . . . . . . . . : 10.57.9.254 Primary WINS Server . . . . . . . : 10.57.9.254 Ethernet adapter Local Area Connection: Connection-specific DNS Suffix . : Description . . . . . . . . . . . : AMD Family PCI Ethernet Adapter Physical Address. . . . . . . . . : 00-80-5F-88-60-9A DHCP Enabled. . . . . . . . . . . : No IP Address. . . . . . . . . . . . : 199.199.40.22 Autoconfiguration Enabled . . . . : Yes Subnet Mask . . . . . . . . . . . : 255.255.255.0 Default Gateway . . . . . . . . . : 199.199.40.1 DNS Servers . . . . . . . . . . . : 199.199.40.254 Primary WINS Server . . . . . . . : 199.199.40.254
Type ping -? to see what command-line options are available. Ping allows you to specify the size of packets to use, how many to send, whether to record the route used, what TTL value to use, and whether to set the don’t fragment flag. See the PMTU discovery section of this document for details on using ping to manually determine the PMTU between two computers. The following example illustrates how to send two pings, each 1450 bytes in size, to address 10.99.99.2: C:\>ping -n 2 -l 1450 10.99.99.2 Pinging 10.99.99.2 with 1450 bytes of data: Reply from 10.99.99.2: bytes=1450 time<10ms TTL=32 Reply from 10.99.99.2: bytes=1450 time<10ms TTL=32 Ping statistics for 10.99.99.2: Packets: Sent = 2, Received = 2, Lost = 0 (0% loss), Approximate round trip times in milliseconds: Minimum = 0ms, Maximum = 0ms, Average = 0ms By default, ping waits one second for each response to be returned before timing out. If the remote system being pinged is across a high-delay link, such as a satellite link, responses could take longer to be returned. The -w (wait) switch can be used to specify a longer time-out. Computers using IPSec may require several seconds to set up a security association before they respond to a ping. Directory: pub -> doc doc -> Assembly language/machine language/coding tutorial part one by scatt index prefix part one : The Basics An Introduction. First Steps Processors Bits and Bytes doc -> English words and phrases doc -> Notices regarding the use of these documents doc -> Gsg-linux-vt 01 doc -> In Proceedings of 15 th doc -> Performance Modeling of Parallel and Distributed Computing Using pace doc -> A dragon in the tube doc -> Revisão Bibliográfica: Learning Vector Quantization 28/04/2003 doc -> Revisão bibliográfica redes neurais recorrentes doc -> Revisão Bibliográfica: Autômatos Celulares Download 0.63 Mb. Share with your friends:
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