Disconnecting DHCP Clients

Wondering how to disconnect DCHP clients from the Mac OS X Server?

Disconnect in what way?
The DHCP standard basically gives the client a lease on the IP configuration. As far as it knows, that lease is good for as long as the TTL says. You can control the TTL used so that longer or shorter leases are offered as needed (e.g. 1 hour, 1 day, 2 weeks, etc.), but once that lease is accepted you can't easily revoke it.

Similar Messages

  • WRT400N - issues with brief disconnects and DHCP client table

    Hello,
    I recently bought a WRT400N to replace my (seemingly) dead WRT54GS. It worked great out of the box, and setup was quick and intuitive, just like my previous router. It came with firmware version 1.0.10 B19.
    I'm having two problems. First, while playing some online games, I'm getting brief disconnects every 2-3 minutes. It's usually just enough to make the screen studder (I'll get a "Connection Interrupted" message for a split second), and then it goes away. It's happening often enough where it's causing issues, though. My computer is connected directly to the router via CAT 6, and the only component that has changed since the issue started is  the router itself. To add confusion to the problem, when I do a tracert to something like Google, most of the hops come back fine, but I'm noticing it takes 4-5 seconds before it lists an IP address for any given hop, UNLESS a domain name is specified. The actual columns with the latency numbers are filled in quickly, but the IP address itself at the end of the line hangs for a minute. For example, the  final hop, "12    22 ms    24 ms    23 ms  od-in-f104.google.com [64.233.161.104]" is displayed instantly, but any hops along the way that just show an IP address, such as "11    27 ms    26 ms    25 ms  216.239.48.190" have a long pause before the IP address (bold) is displayed. Normally I would think it's a problem with the routers along the way, but the delay even happens before it displays the hop to my router's IP - 192.168.1.1. Very weird. I wasn't sure if these issues were related.
    The second problem is the DHCP client table in the router's web administration utility. On my old router, the DHCP client table always displayed all computers that were connected to the router (DHCP set to auto). With the WRT400N, I'm noticing only a few of the machines are actually showing up. They're all being assigned IPs without any issues, and they're all able to connect; they're just not showing up in the table. I often check the client table to see who's connected or grab a MAC address when I need to mess with QoS or access restriction, so the fact that some clients are missing is a bit annoying. The old router didn't have this issue.
    Thank you. 

    As you are facing this problem with the Wired Computer, then i think you need to change some settings on your Router. Once you login to the Router GUI, below the Setup tab you will find MTU, which will be set to AUTO,So change it to Manual and change the Size from 1500 to 1365 and click on Save Settings. Once you are done, now try to play the Games and check if you are facing the same problem or not.
    If still you face the same problem, then i think you need to Re-Flash the firmware on you Router.. Go to website linksysbycisco.com/downloads .........insert model no of your router in serach tab......select proper version of your router........download the firmware file......save that file on desktop..
    Follow these steps to upgrade the firmware on the device : -
    Open an Internet Explorer browser page on a computer hard wired to the router...
    In the address bar type - 192.168.1.1...Leave the Username blank & in Password use admin in lower case...
    Click on the 'Administration' tab- Then click on the 'Firmware Upgrade' sub tab- Here click on 'Browse' and browse the .bin firmware file and click on "Upgrade"...
    Wait for few seconds until it shows that "Upgrade is successful"  After the firmware upgrade, click on "Reboot" and you will be returned back to the same page OR it will say "Page cannot be displayed".
    Now reset your router :
    Press and hold the reset button for 30 seconds...Release the reset button...Unplug the power cable from your router, wait for 30 seconds and re-connect the power cable...Now re-configure your router...

  • E4200v2 - DHCP client list NEVER displays

    As the most expensive and hyped "consumer router" at the local big-box stores, and after already returning a Netgear N600 that appeared to be defective, I had high hopes that this router would work properly and I could stop fooling with router settings and move on to real work. And I'll acknowledge that for a lot of folks this router will probably be fine. I didn't do any speed measurements or methodical testing, but it seems pretty fast and using it for more than three weeks it seemed reliable. However, it had several issues that were maddening and ultimately for me, unacceptable. Summarized as follows:
    > The DHCP client list NEVER displays all the clients connected on my network, no matter how many times I look. These clients are actively transferring data, and I can download free programs from the web that report all clients reliably. Why is this so difficult??
    > The logging feature is ridiculous - it often didn't log events that I knew had occurred, and even when they were shown, you would only see an entry if you checked the log very quickly after the event (some sort of "auto-flush" function that makes the whole feature pretty useless).
    > The previous issues are annoying - but this was the deal-breaker. I could not connect to an OpenVPN device on my network through this router. I could connect to the device locally, I could connect to other devices remotely through other forwarded ports, and I could see in the log (if I looked quickly enough) that the router was seeing the connection attempt to the OpenVPN device, but it was getting blocked. Many hours searching forums and experimenting with router settings / firmware updates did not help.
    > In the pursuit of resolving the third issue, and with very low expectations, I contacted Linksys tech support. This proved to be a complete waste of time. After working through the front-line guy who only knew how to look through the User's Guide, I was connected to another person who was even more clueless and was almost robotic in his hard-coded sequence of attempts to guide me through silly procedures that had absolutely nothing to do with my problem. After again asking if I could speak to someone that might actually understand the issue I was put on hold for more than 20 minutes, at which point the call was disconnected (I think this means they hung up on me).
    So once again I'm returning an expensive router that doesn't work properly and will be trying something else. It shouldn't be this difficult.

    With reference to your post I would like to know that does all the client devices on your network runs on DHCP or some of them have static IP address as well? The devices which are running on static IP address will not be displayed in the DHCP client table.
    Regarding the logs that are not being created on the router for any event that takes place could be because of the reason that you might be using another router or a gateway before your linksys router.
    As far as your VPN issue is concerned please try to disable the firewall of the router and then try to connect to the open VPN device because this router acts like a VPN passthrough. Click on the following link to know how to disable the router's firewall http://www6.nohold.net/Cisco2/ukp.aspx?vw=1&docid=87795adab27b4bd7a432e03be4e28e8d_17347.xml&pid=80&...

  • Using Extreme in Bridge mode, can't see the DHCP clients if the D-Link router

    I have an Airport Extreme attached to my DLink modem/router.  I have configured the Airport Extreme in Bridge mode, and I was expecting all clients to show up in my D-Link router.  Although the configuration works most of the time, I have been experience a few issues:
    1.  From time to time, computers attached (both Windows and/or Mac) complain about an IP address conflict.  I can ignore the error and it works fine.
    2. From time to time, I loose Internet connectivity, and I need to disconnect my computer and reconnect again to solve the issue.  This is not necessarily linked to symptom #1
    3. On my D-Link router/modem (which I only use to connect my Airport to my ISP), if I check the DHCP clients, I can see the Airport router connected and *some* of the wireless clients that connect through the Airport.  The list changes quite randomly, and at times, I see the airport appearing twice with different IP addresses.
    Any help configuring it "right" will be appreciated!
    Alain

    When the AirPort Extreme is in bridge mode, the AirPort Extreme is simply passing through the DHCP settings and services that are handled by the D-Link modem/router.
    In other words, the D-Link device is in total charge of the DHCP services for devices on the network.
    You might want to check with D-Link support to see if they have any recommended practices for configuing the modem/router when another router....the AirPort Extreme in this case....is being used in bridge mode on the network

  • Refreshing the DHCP client table

    I just got an EA3500 and I guess I don't understand what "Refresh" does when viewing the DHCP client table under the "Status", "Local Network" tab of the web interface, either that or it's not working.  If I have active wired and wireless clients and I power off the EA3500, wait a few minutes, then power it back on, the table is blank.  If I hit "Refresh" I would expect it to re-populate the table with the connected clients.  For whatever reason, it doesn't.  I have to physically disconnect and reconnect the E-net cable, or power cycle the wireless client to get them to reappear in the table.  Is something wrong with the router or its s/w, or is that not what "Refresh" is supposed to do?
    Thanks in advance for any thoughts you might have.

    Diablo_692 wrote:
    The thread below would seem to indicate that this problem has been around awhile with different routers.  The lease times will refresh, but devices won't appear if they're not already in the table.
    http://homecommunity.cisco.com/t5/Wireless-Routers/Devices-missing-in-DHCP-Client-Table/td-p/7984
    When your computer needs an address, it will send a demand to the router using DHCP. The router's DHCP server then LEASES an IP address for a short amount of time. The computer has to RENEW the lease once in a while to make sure the router knows that the address is still in use. Routers like these save the DHCP information in temporary memory only. When you reboot the router, it no longer remembers who has what address until someone renews again.

  • Missing Wireless Devices On DHCP Client Table

    I’ll always have three wired devices connected on my router at all times and other wireless devices but I disconnect them when I'm done using them. I’ve recently left two wireless devices connect all the time but what seems after a week or so all my wireless devices stop showing up on my DHCP Client Table. Even though they stop showing up on the DHCP Client Table they still work fine and are still connected to the internet. I already tried rebooting my router and that seems to fix it. I have an E2000 Router with the latest Firmware: 1.0.04 I haven’t had any problems with disconnects or anything. My question is why is this happening and how do I fix it or does the router not support devices been connected for days? Thanks in advance.

    There is no fix for this problem as it's not a problem. Maybe your wireless devices don't renew the lease at some point but just keep using the current IP address. Maybe it's a bug in firmware. But as you have noticed it does not cause connection problems. I think very often there are glitches in the DHCP table of various routers.

  • I want to reserve a static IP address on my Airport extreme.  What is the difference between reserving by MAC Address and DHCP Client ID?

    I want to understand the differences in the way you can reserve a static address for a device on the network.  I had previously set the device itself to an address and then reserved it with DHCP Client ID, which I thought was just the devices static addresss.  I'm not sure if this was in fact correct or just happend to work.  I know what a MAC address is, but I'm not really sure what the DHCP Client ID is. So it would be great if someone could clarify it, and the difference between reserving address by MAC Address or DHCP Client ID.

    A MAC address is a unique identification consisting of letters and numbers in a form that looks like this:
    xx:xx:xx:xx:xx:xx
    Every network device has a MAC address, which can be found on a label on the bottom or back of the device. Apple calls this the Ethernet ID.
    A DHCP Client ID is an optional name that you can assign to a device. For example, on your Mac....
    Open System Preferences (gear icon on the dock)
    Open Network
    Click on Ethernet
    Click Advanced at the lower right
    You may be able to edit the DHCP Client  ID here....for example.....you could enter MJ500's MacBook in the space provided. That would be the Client ID of your Mac.

  • Cisco ASA 5505 and DHCP Client Problems

    Hi, i have a problem. I've connected my ASA appliance to an ADSL modem, and i dont get an DHCP address on the outside interface (e0/0). I use the asa-722-19.bin firmware.
    I turned on the debugging for the DHCP client and could see that the ASA device was sending out broadcasts but a reply never came. Instead I connected the device to my internal network where the ASA got an address instantly.
    I read somewhere that if I was to use ?ip address dhcp client-id fastethernet 0″, then I got an address from the ISP.
    I tried looking for a similar command on the ASA5505 but I couldn?t find anything. I did however find a page on the Cisco site confirming my suspicions. It said some ISP?s require the client-id field of the DHCPDISCOVER request to be filled.
    I've also read that this issue has beed fixed since a few weeks, now they have released version 7.2(2).22 where you can define ?dhcp-client client-id interface outside? in global configuration mode. Im running 7.2(2).19 and i cannot find any command like that in my appaiance. How do i fix my problem ? Or how do i get about recieving the 7.2(2).22 firmware update.
    Regards !
    Leif

    Hi again! I thought I should share the solution that worked for me. I use software version 7.2(2) on this device. ASDM 5.2(2). In ASDM open configuration / Interfaces. Click in outside (my case 0/0) and press Edit. Then open the tab Advanced and set the correct Active Mac address. Fore some reason its empty by default and the ISP/modem don't like that. You will find the correct MAC address under the help menu / "About ASA". Im sure there is some another way to do this but this is a simple "how-to" that works with Swedens biggest ISP and their standard DSL modem.
    When I used a Linksys DSL modem in bridge mode without the MAC address set I got an inside IP adress (192.168.x.x) from the modem to the ASA. After setting the MAC address I just had to do a renew and got the outside address right away. /Bjorn
    (future users searchwords: no ip from isp, ASA 5505 and cable modem).

  • Have to regularly restart DHCP Client - HP Pavilion 500-205 DT - Windows 7

    HP Pavilion 500-205 DT - Windows 7 Home Premium 64-bit SP1
    Realtek PCIe GBE Family Controller - Driver 7.67.1226.2012
    Bought 3 identical machines for our childcare center. Set them up the same. All work fine except ONE of them becomes inaccessible periodically (daily more-or-less) to the other Windows computers on our little peer-to-peer LAN. You can see it, but cannot access any shared folder. There is NO problem accessing the OTHER computers on the LAN from this one. All 3 machines have the same sharing profile, workgroup, permissions, AV, firewall settings, everything. I realized restarting the computer in question solved the problem immediately but temporarily. I narrowed it down to restarting the DHCP Client service. Do that, everything works fine immediately but temporarily.
    Things I tried:
    Calling HP support - not helpful at all. It is under warranty.
    Disabled IPv6
    Disabled wireless
    Disabled power-saving shutoff of network adapter
    Setting DHCP CLIENT recovery to:
      First Failure = Restart the the Service
     Second Failure = Restart the the Service
     Subsequent Failures = Restart the the Service
     Reset Fail count After = 120
     Restart Service after = 0
    But again, this isn't happening to the other machines with default settings. Nothing works except restarting the DHCP Client service. The loss of access happens with or without someone logged or using it. It has happened since it was first set up.
    I don't know if the HP warranty covers factory-loaded OS. I don't want to restore the thing and start over. I am not an IT professional, just the guy in the office who does these things, but it seems like the network adapter could be defective. I don't know if I can convince a first-level phone support person to have me bring the machine to an authorized service place.
    Any help greatly appreciated,
    Larry
    This question was solved.
    View Solution.

    You're very welcome.
    I would tend to agree, but I wanted to offer you that driver as a last resort.
    This is a consumer to consumer forum.  I don't work for HP, and if you suspect it is a hardware issue, you will need to contact HP technical support and submit a support case under the warranty.
    The warranty covers hardware, and support for the HP software and operating system installed (as long as it is the original factory image that came with the PC and not an operating system you installed).

  • WRT54G v7 WAN DHCP client problem

    I've recently started having a strange problem with my WRT54G. Internet access is via a Cable modem and has been working fine for months, and the cable modem works fine so I suspect the problem is with the router. However the router is also working, mostly, so I figured I'd see if anyone here has any suggestions. Here are the details of the problem:
    The router WAN configuration was set to DHCP.
    It used to happily pick up a new IP address from the cable modem whenever necessary.
    One night the router stopped picking up an IP on the WAN side. (nothing was changed. I'm the only one in the house who goes anywhere near the router)
    Connecting the modem directly to a PC works fine (suggesting the modem's DHCP server is fine).
    Copying the WAN IP config from the PC to the router, as a Static IP, also allows it to work when the modem is plugged back into the router and the router to a PC (which is how it's setup now, but it's a pain to have to mess with the physical connections and manually reconfigure the router every time the modem drops a connection (which is another issue, but not one for this forum...)).
    So both the modem and the router seem to work except for the router's DHCP client. It works fine as a DHCP server for the LAN.
    The firmware was already upgraded (and working), I've followed the standard power-cycle procedure, I've released and renewed the IP via the Status tab in the web interface, and I've tried resetting the router using both the button on the unit and via the web interface to revert to factory defaults.
    Any suggestions?
    Solved!
    Go to Solution.

    I also had this problem which occurred after >2 years of the router working fine.  After changing MTU to 1300, cloning the PC MAC address, and power cycling the router and modem fixed the problem.  But I was curious to see which change did the trick, so I changed both back to the default (MTU = auto and not cloning the MAC address) and it worked fine!  I think the router problem is intermittant and may appear to be fixed by changing setting, but I fully expect it to reoccur. 

  • How to configure dhcp client identifier

    Hi Everybody,
    The DHCP client ID is an id that is unique for DHCP clients at least in the same subnet. Usually the client uses MAC-address as Client-Identifier in the DHCPDISCOVER message. The Client-Identifier may be different other than MAC-Address, For example a FQDN name, as per the RFC 2132 Ref, (code 61).+_
    Usaually, we use the following to bind the ip address based on MAC-address
    pntadm -r SUNWfiles -p /var/dhcp -A 10.42.32.86 -i '0:3:ba:a5:a9:93' -a 10.42.32.80
    At server side, I am using the following for specifying the FQDN name.
    pntadm -r SUNWfiles -p /var/dhcp -A 10.42.32.86 -i 'one.atr.com' -a 10.42.32.80
    and at client side, I am inserting the following entry in the /etc/default/dhcpagent file
    CLIENT_ID='one.atr.com'
    But this is not working. What I am doing wrong.
    +1. At the server side, then how to assign the ip addresses to the clients , if the Client-Identifier is FQDN name in the DHCPDISCOVER message other than MAC-Address.+
    +2. How to configure the client-identifier as FQDN name at client side.+
    Please help me,
    Thanks Inadvance,
    Mummaneni.

    Sandman,
    Here is an example of a router acting as a DHCP server. Please remember that you have to exclude IP addresses that you don't want to lease out.
    ip dhcp pool example
    import all
    network 192.168.1.0 255.255.255.0
    dns-server 1.2.3.4
    default-router 192.168.1.1
    ip dhcp excluded-address 192.168.1.1 192.168.1.149
    ip dhcp excluded-address 192.168.1.200 192.168.1.254
    HTH,
    Mark

  • How to setup default gateway in a DHCP client. The default gateway will be the Ip address of the server that has RRAS installed, hence routing cabalities.

    How to setup default gateway in a DHCP client. The default gateway will be the Ip address of the server that has RRAS installed, hence routing cabalities.

    Hi Bill,
    Thank you for replying back...Yes, I was actually asking how do you set the default gateway address on the DHCP server?,
    I believe I got the answer below:
    To configure the DHCP default gateway option Click Start, point to Administrative Tools and then click DHCP. In the console tree, expand the applicable DHCP server, expand IPv4, and then right-click Scope Options Click Configure Options, check 003
    Router, type the applicable Server name and IP address, and then click OK.
    Thank you

  • DHCP client fails to get an valid IP address from DHCP server. windows 8.1

    I have a win 8.1 Pro  64 bit pc in my office .I'm trying to connect it to my wireless cisco router with either wireless or hardwired connection but I get an error in the event viewer with discription DHCP error 1007. and Ip address showing
    169.254.93.17 but our dhcp range is 192.168.1.x
    Log Name:      Microsoft-Windows-Dhcp-
    Source:        Microsoft-Windows-Dhcp-Client
    Date:          23/Jun/2014 12:03:21 PM
    Event ID:      1001
    Task Category: Address Configuration State Event
    Level:         Error
    Keywords:      (1)
    User:          LOCAL SERVICE
    Computer:      sanddeplap.vts.com
    Description:
    Your computer was not assigned an address from the network (by the DHCP Server) for the Network Card with network address 0xF4B7E22D8721.  The following error occurred: 0x79. Your computer will continue to try and obtain an address on its
    own from the network address (DHCP) server.
    Event Xml:
    <Event xmlns="http://schemas.">
      <System>
        <Provider Name="Microsoft-Windows-Dhcp-
        <EventID>1001</EventID>
        <Version>0</Version>
        <Level>2</Level>
        <Task>3</Task>
        <Opcode>75</Opcode>
        <Keywords>0x4000000000000001</
        <TimeCreated SystemTime="2014-06-23T08:03:
        <EventRecordID>363</
        <Correlation />
        <Execution ProcessID="988" ThreadID="7932" />
        <Channel>Microsoft-Windows-
        <Computer>sanddeplap.vts.com</
        <Security UserID="S-1-5-19" />
      </System>
      <EventData>
        <Data Name="HWLength">6</Data>
        <Data Name="HWAddress">F4B7E22D8721<
        <Data Name="StatusCode">121</Data>
      </EventData>
    </Event>
    I tried to track issue with microsoft network monitor I'm attaching the capture file also please help me to sort out this issue
    capture report https://onedrive.live.com/redir?resid=AFE3D0245A92F6F8%21183

    The issue is that your machine is not being assigned an IP address / was unable to reach the DHCP server to receive one. The 169.254.x.x IP your machine is showing isn't assigned from DHCP, it's assigned by the local machine and is referred to as an APIPA
    address.
    So something is preventing your machine from reaching your DHCP server, which could one of a number of things. In the first instance I'd suggest having a look at
    http://epan36.blogspot.co.uk/2012/09/eventid-1001-dhcp-your-computer-was-not.html which lists several of things that could cause this error and things you can try in order to resolve it.
    If none of those work, can you confirm whether you have any other machines connecting via the same method on the network, which might indicate whether this is an issue at the machine end or somewhere between the machine and DHCP server?

  • Disconnect a client

    i have two client machines ( client A ,client B) and a server.
    i create a interface for server. it will run into the server. using this interface administrator can monitor client activities.
    i want to write a program for disconnect particular client from the main rmi server. but other client should run with out any problem.
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    If you mean to disconnect a client after it has called the main server, you don't have to do anything, the connections are dropped after 15 seconds.
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  • Where is option to "disconnect wifi clients" from personal hotspot?

    According to this Apple Knowledge Base article, there should be an option in Settings > Wifi to "disconnect wifi clients" who are connected to the iPhone via personal hotspot: http://support.apple.com/kb/HT4517
    I do not see that in the Settings. I am on an iPhone 4, iOS 5.01, AT&T. Does anyone else see this? Was it removed in an iOS update? The KB article says it was updated December 14, 2011, so it should be pretty current.

    I too was looking for it and it's. It in my iPhone 4 AT&amp;T 5.0.1 Perhaps it's not in this firmware update, in another location or apple decided to axe this option.
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