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Slow throughput - there is connection but data is slowly getting in

IPCONFIG

Displays all current TCP/IP network configuration values and refreshes Dynamic Host Configuration Protocol (DHCP) and Domain Name System (DNS) settings. Used without parameters, ipconfig displays the IP address, subnet mask, and default gateway for all adapters.

Syntax ipconfig [/all] [/renew [Adapter]] [/release [Adapter]] [/flushdns] [/displaydns] [/registerdns] [/showclassid Adapter] [/setclassid Adapter [ClassID]]

Parameters

/all

Displays the full TCP/IP configuration for all adapters. Without this parameter, ipconfig displays only the IP address, subnet mask, and default gateway values for each adapter. Adapters can represent physical interfaces, such as installed network adapters, or logical interfaces, such as dial-up connections.

/renew [Adapter]

Renews DHCP configuration for all adapters (if an adapter is not specified) or for a specific adapter if the Adapter parameter is included. This parameter is available only on computers with adapters that are configured to obtain an IP address automatically. To specify an adapter name, type the adapter name that appears when you use ipconfig without parameters.

/release [Adapter]

Sends a DHCPRELEASE message to the DHCP server to release the current DHCP configuration and discard the IP address configuration for either all adapters (if an adapter is not specified) or for a specific adapter if the Adapter parameter is included. This parameter disables TCP/IP for adapters configured to obtain an IP address automatically. To specify an adapter name, type the adapter name that appears when you use ipconfig without parameters.

/flushdns Flushes and resets the contents of the DNS client resolver cache. During DNS troubleshooting, you can use this procedure to discard negative cache entries from the cache, as well as any other entries that have been added dynamically.

/displaydns

Displays the contents of the DNS client resolver cache, which includes both entries preloaded from the local Hosts file and any recently obtained resource records for name queries resolved by the computer. The DNS Client service uses this information to resolve frequently queried names quickly, before querying its configured DNS servers.

/registerdns

Initiates manual dynamic registration for the DNS names and IP addresses that are configured at a computer. You can use this parameter to troubleshoot a failed DNS name registration or resolve a dynamic update problem between a client and the DNS server without rebooting the client computer. The DNS settings in the advanced properties of the TCP/IP protocol determine which names are registered in DNS.

/showclassid Adapter

Displays the DHCP class ID for a specified adapter. To see the DHCP class ID for all adapters, use the asterisk (*) wildcard character in place of Adapter. This parameter is available only on computers with adapters that are configured to obtain an IP address automatically.

/setclassid Adapter [ClassID]

Configures the DHCP class ID for a specified adapter. To set the DHCP class ID for all adapters, use the asterisk (*) wildcard character in place of Adapter. This parameter is available only on computers with adapters that are configured to obtain an IP address automatically. If a DHCP class ID is not specified, the current class ID is removed.

/?

Displays help at the command prompt.

Remarks

The ipconfig command is the command-line equivalent to the winipcfg command, which is available in Windows Millennium Edition, Windows 98, and Windows 95. Although Windows XP does not include a graphical equivalent to the winipcfg command, you can use Network Connections to view and renew an IP address. To do this, open Network Connections, right-click a network connection, click Status, and then click the Support tab.

This command is most useful on computers that are configured to obtain an IP address automatically. This enables users to determine which TCP/IP configuration values have been configured by DHCP, Automatic Private IP Addressing (APIPA), or an alternate configuration.

If the Adapter name contains any spaces, use quotation marks around the adapter name (that is, "Adapter Name"). For adapter names, ipconfig supports the use of the asterisk (*) wildcard character to specify either adapters with names that begin with a specified string or adapters with names that contain a specified string. For example, Local* matches all adapters that start with the string Local and *Con* matches all adapters that contain the string Con. This command is available only if the Internet Protocol (TCP/IP) protocol is installed as a component in the properties of a network adapter in Network Connections.

Examples To display the basic TCP/IP configuration for all adapters, type:

ipconfig

To display the full TCP/IP configuration for all adapters, type:

ipconfig /all

To renew a DHCP-assigned IP address configuration for only the Local Area Connection adapter, type:

ipconfig /renew "Local Area Connection"

To flush the DNS resolver cache when troubleshooting DNS name resolution problems, type:

ipconfig /flushdns

To display the DHCP class ID for all adapters with names that start with Local, type:

ipconfig /showclassid Local*

To set the DHCP class ID for the Local Area Connection adapter to TEST, type:

ipconfig /setclassid "Local Area Connection" TEST

About ipconfig

Ipconfig is a DOS utility which can be used from MS-DOS and a MS-DOS shell to display the network settings currently assigned and given by a network. This command can be utilized to verify a network connection as well as to verify your network settings.

Windows 95, 98, and ME syntax/All Display detailed information. /Batch [file] Write to file or ./WINIPCFG.OUT /renew_all Renew all adapters. /release_all Release all adapters. /renew N Renew adapter N. /release N Release adapter N

Windows 2000 and XP syntax

/all		Display full configuration information.

/release Release the IP address for the specified adapter. /renew Renew the IP address for the specified adapter. /flushdns Purges the DNS Resolver cache. /registerdns Refreshes all DHCP leases and re-registers DNS names /displaydns Display the contents of the DNS Resolver Cache. /showclassid Displays all the dhcp class IDs allowed for adapter. /setclassid Modifies the dhcp class id.

The default is to display only the IP address, subnet mask and default gateway for each adapter bound to TCP/IP.

For Release and Renew, if no adapter name is specified, then the IP address leases for all adapters bound to TCP/IP will be released or renewed.

For SetClassID, if no class id is specified, then the classid is removed. Examples

Below is an example of the output you should expect to see when running ipconfig /all Because of security concerns, the below network information is false.

Windows 98 IP Configuration

Host Name . . . . . . . . . : COMPUTERH1 DNS Servers . . . . . . . . : 123.45.67.8 111.111.111.1 111.111.111.1 Node Type . . . . . . . . . : Broadcast NetBIOS Scope ID. . . . . . : IP Routing Enabled. . . . . : No WINS Proxy Enabled. . . . . : No NetBIOS Resolution Uses DNS : No

0 Ethernet adapter :

Description . . . . . . . . : PPP Adapter. Physical Address. . . . . . : 44-44-44-54-00-00 DHCP Enabled. . . . . . . . : Yes IP Address. . . . . . . . . : 123.45.67.802 Subnet Mask . . . . . . . . : 255.255.0.0 Default Gateway . . . . . . : 123.45.67.801 DHCP Server . . . . . . . . : 255.255.255.255 Primary WINS Server . . . . : Secondary WINS Server . . . : Lease Obtained. . . . . . . : 01 01 80 12:00:00 AM Lease Expires . . . . . . . : 01 01 80 12:00:00 AM

1 Ethernet adapter :

Description . . . . . . . . : 3Com 3C90x Ethernet Adapter Physical Address. . . . . . : 00-50-04-62-F7-23 DHCP Enabled. . . . . . . . : Yes IP Address. . . . . . . . . : 111.111.111.108 Subnet Mask . . . . . . . . : 255.255.255.0 Default Gateway . . . . . . : 111.111.111.1 DHCP Server . . . . . . . . : 111.111.111.1 Primary WINS Server . . . . : Secondary WINS Server . . . : Lease Obtained. . . . . . . : 11 16 00 12:12:44 AM Lease Expires . . . . . . . :

ipconfig /displaydns

Running the above command would display all the DNS information.

ipconfig /flushdns

Delete all DNS enteries.

An error occurred while renewing interface

Symptoms: When trying to release and renew the IP address using the Ipconfig command, you may receive the following error message: “An error occurred while renewing interface 'Internet': An operation was attempted on something that is not a socket.”

Cause: These issues may occur if the Winsock registry keys are damaged or corrupted.

Can ping ip but not name

I have a situation here where I could ping an IP of a computer but how come I couldn't ping with its computer name?

1. Incorrect WINS and DNS settings. 2. Incorrect TCP/IP settings 3. Check lmhosts and hosts files

Can ping IP but not hostname after installed/upgraded software

Cause: the may modify the networking configuration in registry.

Can receive IP packets but not send them

Symptoms: When using ipconfig command, you may have no IP address or no Automatic Private IP Addressing (APIPA) address. You may be receiving IP packets but not sending them.

Cause: These issues may occur if the Winsock registry keys are damaged or corrupted.

Can't ping my own IP address

Failure to ping a computer's own IP address is most likely caused by a firewall program or improperly configured. Can't obtain/renew IP addresses from the DHCP server

Symptoms: 1) you have a DHCP client which may not be able to obtain/renew IP addresses from the DHCP server intermittently. 2) after setup a workstation to obtain an IP address from DHCP, the machine can't ping others and ipconfig /all shows Autoconfiguration IP Address. . . : 169.254.x.x. Resolutions: 1) If this is XP, obtain the latest service pack for Windows XP. 2) Use the Network Diagnostics tool to identify any failed settings. To do this, go to Help and Support>Use Tools to view your computer information and diagnose problems>Network Diagnostics>Scan your system. When the process finishes, check for any items marked "FAILED" in red, expand those categories, and view the additional details about what the testing showed. 3) Assign a static ip on the client and ping the DHCP server. If you can't ping the DHCP server, check the connection and hardware. 4) If you can ping the DHCP after assigning static ip, check the DHCP settings. 5) Make sure no firewall is running on your LAN. 6) Run Repair this connection if it is XP. Or use netsh to reset TCP/IP configuration. 7) If it is win98/w2k, remove and reinstall TCP/IP. 8) Try to upgrade the new NIC driver. 9) Make sure you don't run out of IPs in the DHCP scope. 10) If you use a router as DHCP, you may want to upgrade the firmware.

Cannot use the 2nd NIC

Symptom: You have two computers and each one has two NICs. You are using the first NIC with 192.168.1.0/24 to connect the Internet and it works. You also want to use the 2nd NIC with crossover cable to connect to each other using the same IP range (one is 192.168.1.10 and another is 192.168.1.11). You can't ping each other (192.168.1.10 and 192.168.1.11).

Resolution: The 2nd NICs should use the different IP range.

Still need help, contact consultant Your feedback and contributions to this web site IP address conflicts SYMPTOMS: when trying to set the IP address on a NIC, you may receive the following error message: "The IP address XXX.XXX.XXX.XXX you have entered for this network adapter is already assigned to another adapter Name of adapter. Name of adapter is hidden from the network and Dial-up Connections folder because it is not physically in the computer or is a legacy adapter that is not working. If the same address is assigned to both adapters and they become active, only one of them will use this address. This may result in incorrect system configuration. Do you want to enter a different IP address for this adapter in the list of IP addresses in the advanced dialog box? " RESOLUTION: 1. If you click Yes, you see the TCP/IP properties where you can change the IP address. Then assign the different IP. 2. If you click No, the IP address is assigned to the network adapter. To resolve this problem, uninstall the ghosted network adapter from the registry: At command prompt, type set devmgr_show_nonpresent_devices=1, and then press ENTER. Type Start DEVMGMT.MSC, and then press ENTER. Click View, and then click Show Hidden Devices. Expand the Network Adapters tree and right-click the dimmed network adapter, and then click Uninstall.

No IP while the network cable is disconnected

Symptoms: your computer has a static IP. However, the ipconfig shows no IP (Media State - Cable Disconnected) while the network cable is disconnected.

Cause: this is by design. If you have some software using TCP/IP whiteout connecting to a network, you may setup it manually.

No operation can be performed on the adapter

Symptoms: when attempting to use ipconfig /release or renew command, you get "No operation can be performed on the adapter <xxxxx...> as this connection has its media/cable disconnected.

Causes: 1. The network is up-plugged or no NIC. 2. You are using static IP.

One-way ping only

If you can ping other computers and other computers can't ping your computer, this is often caused by an improperly configured firewall on you computer. For example, ICF should not be enabled on LAN NIC.

Some Win9x obtain different subnet mask

Symptoms: In your domain network, some computers (most are win9x) obtain mask 255.255.255.0 instead of 255.0.0.0 randomly and they can't logon to the Domain. IPCONFIG /renew doesn't fix the problem. If you assign static ip and correct mask, the computer will be able to logon without any problem. If you check the WINS, you may find many bad records.

Possible reasons: you may have another network device (possible a router) except main DHCP functions as a DHCP.

The DHCP client has obtained an IP address that is already in use on the network

Symptom: When trying to renew IP, you may get this error "An error occurred while renewing the interface Local Area Connection: The DHCP client has obtained an IP address that is already in use on the network. The local interface will be disabled until the DHCP client can obtain a new address."

Resolution: 1. Release and the renew it. 2. Clean the internal DNS and WINS records. Refer to case 083104LR

Unexpected network failure or insufficient access or access is denied

Symptoms: when trying to use ipconfig /release or renew, you may receive the following message "The following error occurred when releasing adapter Local Area Connection: Unexpected network failure or insufficient access or access is denied"

Cause: You don't have permission to release or renew the IP.

Why do I get 169.254.x.x IP?

Symptom: The Internet Assigned Numbers Authority (IANA) has reserved 169.254.0.0-169.254.255.255 for Automatic Private IP Addressing. If the computer can't get ip from DHCP, APIPA provides an address that is guaranteed not to conflict with routable addresses.

Resolutions: 1) Make sure you have good connection. 2) Check the hardware and settings. 3) Make sure the DHCP is working. 4) For the test, you can assign static ip. If static ip works, it is possible DHCP issue. If static ip doesn't work, check the hardware or connection. 5) WinSock2 stack may be corrupted and need to repair.

Why the ipconfig shows 0.0.0.0 ip even you have assigned a static ip

Question: I have assigned a static ip, subnet to the computer, but the ipconfig shows IP address is 0.0.0.0 and subnet mask 0.0.0.0.. Why?

Answer: An existing IP address on the network has the same IP address. You may use tracert ip, WINS and DNS records to find out another computer using the same IP.

If your laptop users frequently disconnect from one network segment and reconnect to another network segment, they may not be able to access the second network. Resolution will be run ipconfig /registerdns.