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The Dynamic Host Configuration Protocol (DHCP) is an auto configuration protocol used on IP networks and an extension of the Bootstrap Protocol. DHCP allows for computers to be configured automatically to communicate with each other over an IP network without the need for manual setup by a network administrator. The implementation of DHCP relies on a DHCP server to hand out network configuration information to DHCP-capable clients that request an IP address (and other information required or useful in communicating with other devices on an IP network). In addition to an IP address, common configuration information served over DHCP includes a default gateway, subnet mask and DNS sever(s).

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Dear All

I have a new Mikrotik cloud core router, I need some help, please.

Interface one - ISP

Interface Two - Network Switch DHCP Scope 192.168.88.**

Interface, 12,11,10 & 9 Brideged together for DL380 Gen 9 NIC Team DHCP Scope? 192.168.89.**

I would like to be able to ping anything in any of the two networks, but I can't seem to figure this part out and need a little help, please.

Thanks
Alex
0
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Need to refresh DHCP IP address reassign Needed to command
0
Dear experts

My situation is quite complicated.
Generally, I m creating an VPN server.
For different client connect to the VPN Server from different country, I would like to provide different dhcp-range.

I understand that dnsmasq support multiple network.
My question is how I can use the tag indicator and the client will collect the correct dhcp-range in the VPN connection situation.

e.g.
------------------------------------------
# Address range for country1 clients
dhcp-range=tag:country1,192.168.1.10,192.168.1.19,255.255. 255.0,1h

# Address range for country2 clients
dhcp-range=tag:country2,192.168.1.20,192.168.1.29,255.2 55.255.0,1h

# DHCP options given to known clients

# Subnet mask
dhcp-option=1,255.255.255.0
# Default gateway
dhcp-option=3,192.168.1.1
# DNS server
dhcp-option=6,192.168.1.3
# Broadcast address
dhcp-option=28,192.168.1.255
------------------------------------------
0
Hello,

I moving several scopes from different DHCP server. When Importing the scope I receive the following error:

Error while importing class "Default Routing and Remote Access Class."
This class conflicts with the existing class "Classe de routage et d'accès distant par défaut." An internal error occurred.

I found that the error is related to the language ?? but still did not find a solution.

Any help?

Thank you
0
i have 1 default lan and 3 vlans.
setup on our watchgaurd firewall
vlan10 ip address 172.16.0.1/23 dhcp relay to the dns server
vlan 20 ip address 192.168.20.1/23 dhcp relay to the dns server
vlan 30 ip address 192.168.30.1/23 dhcp relay to the dns server

On the dns server i have the 3 vlans with thier own scope and in thier scope options i have the router set to
vlan 10 172.16.0.1
vlan 20 192.168.20.1
vlan 30 192.168.30.1
in the dns server routing and remote access i have the ipv4 dhcp relay agent set to 172.16.0.1, 192.168.10.1, 192.168.20.1, 192.168.30.1

all of our switches have the vlans setup also
any time i connect a pc to a switch that has its port set to any of the vlans it gives a bad ip address, 169....
anything on our defualt lan works

for a while i was getting this error on our dns server event viewer.
IPBOOTP was unable to receive an incoming message on the local interface with IP address 191.168.0.4. The data is the error code.

i restarted and also deleted and created the routing and remote acces dhcp relay agent
I dont get that error code any longer but the vlans still dont work
HELP
0
Hi Experts,
I want to be able to use some IP phones on a different vlan on HP procurve switches.
The phones are on VLAN1 192.x.x.x but the vlan the phone is plugged into is say vlan 100 10.x.x.x
I thought an ip helper would be all i needed. My phones are on 192.168.x.x
my normal computers are on VLAN 5 192.168.4.0
the phones do use vlan 1 for the dhcp scope options and changes the vlan to VLAN 2 and then this sends the phone to the Mitel server's dhcp. Our normal network works fine and phones get an IP on the .2 network. I want to add this new network 10.10.0.0 and pc's will be sat on this switch untagged but they need to get to the 192.168 network to get to VLAN2.

it all routes fine and i can ping across the vlans but the phones are not getting an IP from DHCP. I have tried adding an Ip helper but i am not sure where this goes in the config? vlan or switch? Do the switches need to know about the VLAN 1 or as long as the vlan 2 for phones is there should the phone be ok to find it.
Thanks
0
Hello

We have just rolled out IPAM,

Everything is going ok, except i am not see any AD authentications being recorded only DHCP and NPS.

So we are only seeing user details for NPS authentications, I have ensured audit logging is enabled, but i can not find anything on what could be stopping this.
0
I am remodeling four homes.  I have  installed eight port structured wiring systems in all four.  Each wall jack (room) includes one ethernet jack, one cable jack, and one phone jack.  Everything is homerun to the utility room in the basement. Within the wiring cabinet located there, are punch down blocks and patch panels for all wires and cables. I would like to install  in each cabinet, an eight port router or switch to include an integrated DHCP server, and POE  jacks. One of these Jack's will be wired to a ceiling mounted Wi-Fi access point on the third floor in the center of the home. This device should be dual band AC 1200  or greater. Ultimately, the router or switch will be plugged into a cable modem providing Internet and telephone service. I am having trouble finding the router or switch, which needs to be small enough  to fit inside the wiring panel.  I also need an inexpensive access point device.  The cable modem will be mounted by the cable service provider outside the panel.  This arrangement will allow plug-and-play of any wired or wireless device in the home without the need for a PC  based DHCP server arrangement. Has anyone done this? Any recommendations? I need to keep this reasonably inexpensive.
0
I need to remove a domain controller from a subsite.
The subsite has a 10Mbit link to the main office. This link is and will be used by the organization to route users at this subsite through to the main office where the new domain controller is.

If I remove the server from the office here, and it hosts DHCP, DNS and AD, how can I simply redirect the users to the main office to login and authenticate through?

Will they find the domain controller automatically through the WAN link? Do I need to have something in place to point them there?
Any guides or docs would be much appreciated.
0
Dear experts

Background:
- Softether VPN Server (Fixed public up say: located in Singapore)
- Using Dnsmasq for DHCP
- In Dnsmasq,
           dhcp-range x 2
           Interfaces x 2

Which dhcp-range will be used when VPN client connects to the VPN Server?

Is it possible for me to select dhcp-range when I initiate the connection from different country?
e.g. from Singapore                            --> Singapore, I am getting IP Range192.168.2.10-192.168.2.50
       from Country out of Singapore --> Singapore, I am getting IP Range 10.10.2.10-10.10.2.50

Any idea how I can achieve the above?
I appreciate you advises & ideas in advance.
0
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What does the following two options actually do for DHCPd and does it work with failover?

allow booting;
allow bootp;


Im trying to configure DHCPd Failover and from what Im reading Im not quite sure if DHCP scopes that need PXE boot will work with DHCPd Failover. I believe the two options listed above would be needed but I dont know.  If so, should they be added in the primary and secondary dhcpd.conf files or the dhcpd.master?

Also the two options below -- are they also needed and should they be added in the primary and secondary dhcpd.conf files or the dhcpd.master too?

next-server x.x.x.x;
filename "xxx";

Thanks in advance!

Primary dhcpd.conf file
#authoritative;
ddns-update-style none;
ignore client-updates;
one-lease-per-client true;
omapi-port 7911;

#Failover peer section
failover peer "dhcp-partner" {
  primary;
  address server1.paychex.com;
  port 647;
  peer address server2.paychex.com;
  peer port 647;
  max-response-delay 60;
  max-unacked-updates 10;
  mclt 3600;
  split 153;
  load balance max seconds 3;
}
include "/etc/dhcp/dhcpd.master";

Open in new window


Secondary dhcpd.conf file
#authoritative;
ddns-update-style none;
ignore client-updates;
one-lease-per-client true;
omapi-port 7911;

#Failover peer section
failover peer "dhcp-partner" {
  secondary;
  address server2.paychex.com;
  port 647;
  peer address server1.paychex.com;
  peer port 647;
  max-response-delay 60;
  max-unacked-updates 10;
  load balance max seconds 3;
}
include "/etc/dhcp/dhcpd.master";

Open in new window


dhcpd.master file
option domain-name "example.com";
allow booting;
allow bootp;
next-server x.x.x.x;
filename "xxx";
option option-242 code 242 = string;

#dhcpd wants to listen on its own networks
subnet 17.8.4.0 netmask 255.255.252.0 {
  ignore unknown-clients;
}

#dhcpd wants to listen on its own network
subnet 19.4.8.0 netmask 255.255.252.0 {
  ignore unknown-clients;
}

#Scope [12.4.4.0] TEST PXE Boot
subnet 12.4.4.0 netmask 255.255.252.0 {
  option subnet-mask 255.255.252.0;
  option routers 12.4.4.1;
  option domain-name-servers 12.2.2.198;
  pool {
    failover peer "dhcp-partner";
    default-lease-time 300;
    max-lease-time 360;
    range 12.4.5.0 12.4.5.255;
  }
}

Open in new window

0
Hello Experts,
I need to find a MAC address for a DHCP lease a couple of months ago. I have checked the dhcp folder in system32 but it doesn't go back far enough.
Is there a way to do this?

Many Thanks,
0
Hello Experts,

I am trying to cross compile ISC DHCP on Ubuntu 17.04 32 bit

./configure --prefix=/home/deer/workbench/dhcp/final --sysconfdir=/home/deer/workbench/dhcp/final/etc/dhcp --localstatedir=/var --with-srv-lease-file=/var/lib/dhcpd/dhcpd.leases --with-srv6-lease-file=/var/lib/dhcpd/dhcpd6.leases --with-cli-lease-file=/var/lib/dhclient/dhclient.leases --with-cli6-lease-file=/var/lib/dhclient/dhclient6.leases --host=$TARGETMACH --cache-file=config.cache

#################
Here is config.log file

This file contains any messages produced by compilers while
running configure, to aid debugging if configure makes a mistake.

It was created by DHCP configure 4.2.5-P1, which was
generated by GNU Autoconf 2.61.  Invocation command line was

  $ ./configure --prefix=/home/deer/workbench/dhcp/final --sysconfdir=/home/deer/workbench/dhcp/final/etc/dhcp --localstatedir=/var --with-srv-lease-file=/var/lib/dhcpd/dhcpd.leases --with-srv6-lease-file=/var/lib/dhcpd/dhcpd6.leases --with-cli-lease-file=/var/lib/dhclient/dhclient.leases --with-cli6-lease-file=/var/lib/dhclient/dhclient6.leases --host=arm-none-linux-gnueabi --cache-file=config.cache

## --------- ##
## Platform. ##
## --------- ##

hostname = ubuntu
uname -m = i686
uname -r = 4.10.0-19-generic
uname -s = Linux
uname -v = #21-Ubuntu SMP Thu Apr 6 17:03:14 UTC 2017

/usr/bin/uname -p = unknown
/bin/uname -X     = unknown

/bin/arch              = unknown
/usr/bin/arch -k       = unknown
0
i have problem with routing in my mikrotik.
eth 1--- have 200.x.x.x ( internet)
eth 2 ---192.168.21.1/30
eth3 --- 192.168.4.0/24 ( dhcp server active) ( my local lan)
..................................................................................
i have remote site with ip 172.28.63.32/27 that connect through some router to eth2 (192.168.21.1/30)

i have a nat ( masquerade  ) from may local lan to eth 1 ( internet)
...........................................................................................
routing
DST   0.0.0.0                 gateway  eth1
DST   192.168.21.x       gateway  eth2
Dst   192.168.4.0/24    gateway  eth3
static route  
DSt   172.28.63.32/27     gateway eth2
....................................
fire wall rule

chain forward     .......soure 192.168.4.0/24    Dst 172.28.63.32/27    action  Accept
chain forward     .......soure 192.168.4.0/24    Dst 192.168.21.x     action  Accept
..........................................................................................................
i can ping from router to 172.28.63.x     ( inside the router)  evry thing is good
but i can not ping 172 .28.63.x  from pc in my local lan (192.168.4.0/24) ....( i can not reach to 172.28.x.x from my local lan )

please  help me ... thank you
0
Can someone give feedback if my NIC configuration is wrong.

Connection : Edge Network

                                  TMG Box                                                                                   Domain Box (AD, DHCP and DNS)
Internal Network                        External Network                                                                      Internal Network
IP - 10.0.0.1                                  IP - 192.168.137.222                                                                 IP - 10.0.0.2
SM - 255.255.255.0                     SM-255.255.255.0                                                                     SM-255.255.255.0
DF - None                                     DF - 192.168.137.1                                                                    DF - 10.0.0.1
DNS - 10.0.0.2                              DNS - 80.138.5.280                                                                   DNS - 10.0.0.2
                                                       DNS - 80.138.5.30  

Is this a correct configuration? If not please correct me.....
0
These roles are installed on the server:
Active Directory Domain Services
DHCP Server
DNS Server
File Services
Print and Document Services
Web Server (IIS)

Features:
Group Policy Management

When I ping this server even from a PC located in the same physical space - the ping latency is very high.
It goes up as high as 1400ms and fluctuates to as little as 15ms.
At first I thought of port exhaustion and checked with netstat but see nothing wrong. Restarted DNS and DHCP services. Rebooted the server. Still no good.

I can ping the gateway and other PCs in the same subnet without seeing this problem. It is only with this server.

Symantec AV has been installed on this server and runs automatic scans - it hasn't found anything wrong. I installed MBM now and am running a full scan to see if that turns up anything.

What more can I look into?
0
Hey All
So some Windows updates install last Sunday and server was restarted after that had DHCP errors

This computer has at least one dynamically assigned IPv6 address.For reliable DHCPv6 server operation, you should use only static IPv6 addresses.

The DHCP service is not servicing any DHCPv4 clients because none of the active network interfaces have statically configured IPv4 addresses, or there are no active interfaces.

I check the network card and it is set to DHCP and I set it back and restart services but same error

 do some online research and find this
 https://technet.microsoft.com/en-us/library/cc774857%28v=ws.10%29.aspx?f=255&MSPPError=-2147217396

and find that i have no NIC listed in the DHCP server bindings
try to Unauthorized but get error
uninstall rolls reboot re install but same

any help would be great
0
I have a number of machines on my network that are picking up their IP address from a server on my network that should not be giving out addresses.

The server in question is an Avaya appliance. It is a Linux machine running voicemail and a One-X portal. Aside from it telling the clients that it is their DHCP server and gateway, it seems to be handing out the correct information including DNS and domain name. It is on the same broadcast and subnet as the actual DHCP server which is running on 2008R2. If I disconnect the server and reboot the machines they pick up their IP from the correct source and all is good again. The machines are however routing their traffic through this appliance because as far as they know, it is their gateway and the appliance seems to be doing it.

I think the problem started when I updated my vsphere environment to 6.5 last weekend. This Avaya server is a virtual machine and doesn't have tools installed, either vmware or open. - This may be a red herring however and the problem may be elsewhere.

The version of the server is 9.0.0.0 build 523 so its a little old.

Any thoughts on solving this one much appreciated. If more details on the network are needed, please ask.
1
Hello.

We are experiencing really irritating issue.

I usually add a computer to a domain with no problem.

But sometimes (and it happens more and more often) after we add a new or reinstalled PC to a domain we are able to ping from this PC the whole network but other PCs and servers cannot reach this new one.

To be clear:
  • DHCP Server assigns IP address without problem
  • DNS Server has both IPv4 and IPv6 adresses of this PC as A record.
  • In all cases above pings work from the new PC only. Event Viewer does not show any error or info.
  • Commands nslookup and set logon shown no error on client all the time.
  • These commands show no error on server all the time: dcdiag /test:registerindns /dnsdomain:your_domain_name + dcdiag /test:connectivity
Everything is set as it should be. Trust me.

What I usually do when it occurs:
1. I restart the computer. Never helps. So then...
1. CMD: ipconfig /registerdns -> then I wait circa 30 mins. It just works or not. If not...
2. I try it again and wait circa an hour. It just works or not. If not...
3. I put the computer out of a domain for a while and then I add it back again. If this doesn't work, I use ipconfig /registerdns command. It just works or not. If not...
4. I use these commands on client: ipconfig /release, then /renew, then /flushdns, then /registerdns. Sometimes I remember to stop Dnscache Service for a while. It just works or not. If …
0
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PDC in DFS environment constantly having  DHCP DNS and AD fail.  I am at a lose.  Rebooting server seems to work some of the time.  DFS shares are not syncing with this machine sporadically, Sites 2 and 3 replicating normally.  HELP
0
Hi i have setup my Cisco v887va on my sky home network. however im not sure if my config is missing something, i get many thousands of CRC errors on the AP from the 2.4 and 5Ghz but 0 from the ethernet cable (used for POE)
my connection will be a constant 30Mb then all of a sudden drop to 2Mb forcing me to reboot. the AP has no fancy config, just basic AP setup with 2.4 and 5 GHz on the same SSID and password. below is the config i am using, my personal details have been changed slightly.
please advice of any mistakes or improvements i could perhaps make to the config.

no service pad
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname Router
!
boot-start-marker
boot-end-marker
!
!
!
no aaa new-model
!
!
memory-size iomem 10
crypto pki token default removal timeout 0
!
!
ip dhcp pool dynamic-pool
   import all
   network 192.168.0.1 255.255.255.0
   default-router 192.168.0.1
   dns-server 90.207.238.97 90.207.238.99
!
!
!
!
!
ip cef
no ipv6 cef
!
!
!
!
!
!
!
!
controller VDSL 0
!
!
!
!
!
!
!
!
interface Ethernet0
mac-address 7xxx.axxx.0xxx
mtu 1492
no ip address
no shutdown
!
interface Ethernet0.101
encapsulation dot1Q 101
ip dhcp client request classless-static-route
ip dhcp client client-id hex 37633463xxxxxxxxxx64343040736b7964736c3a6435316136626565
ip dhcp client hostname 7c4xxxxxxxx0@skydsl|d5xxxxxe
ip address dhcp
no ip redirects
no ip …
0
we have 3 vlans on one network. dhcp and dns are on a 2008 r2 server. the vlans are setup on watchguard firewall. if i put the device in the deny filter in dhcp, it wont get on any of the vlans. i would like to let them connect to one of the vlans. any way to do this?
0
1. Around 05/15/2017 08:01 AM: On our Stockholm Office remote location, they have started reporting that there is no internet access and they don't have access to the servers either while connecting via VPN. Approximate to 30 VPN users where getting APIPA Address 169.254.X.X. But the users connected over network cable, they where able to connect to our private network. The Network Team as confirmed that they can see traffic, monitoring has not detected any issues with LAN or WAN.

As because the DHCP server which is issuing the IPv4 address for VPN users. We have restarted the DHCP service, the VPN users then restarted their client machines. They are connected back to the network. We have only One DHCP server in that remote location which is authorized to lease the IP address for both VPN users and for users connecting Via network cable. We couldn't find any logs in event viewer in relate to this issue. Even we couldn't find any log in DHCP log report in relate to this issue.

We would like to Know what could be the reason for this issue, and the steps that need to be followed in order to avoid this issue in future.

2. We have faced the Similar kind of issue on 08/05/2017 Around 10 AM UK in Wiesbaden Office. In this remote location around 200+ VPN users are got affected. Even on this remote Location we have only one DHCP server which is authorized to lease the IP address for both VPN users and for users connecting Via network cable.

Important: For the DHCP server in…
0
Running a physical server with AD, DHCP, DNS, and File server + Hyper V. (I know it supposed to be split but this is small company with only 5 users.) The VM is designed as Remote Desktop for the 5 users when they are traveling.

I setup the physical server then added the VM. The NIC1 was setup with the static address for the Domain Controller and DNS, Then I added the VM. I added the Virtual Adapter using the Physical NIC2. After I had it setup I was getting not connection back to the physical server until I checked the box to allow the host to share this adaper. That added a vEnternet on the physical machine and using DHCP to get the address.

Is this OK to have the vEthernet as dynamic? Most of the traffic to the physical machine seems to go through that adapter.
0
Hello,

I need an advice:

I'm working on a big project of consolidation of  DHCP.

- we have several sites (7 sites), each site has several location (5), each location has its own DHCP sever
- One site has two dhcp servers (top level) with load balancing (actif-standbuy) already configured

What I did:

- I created a new DHCP server for each site (top level)
- Configured the IP helper on the routers for each location so the workstations can get IP address from the site DHCP
- Two IP helpers are configured one for the site DHCP and the second for the top level standby DHCP server
- Export/import scoops from each location to the new DHCP server.

My Goal:

- Configure failover between each site DHCP and the standby DHCP server of top level
So the site workstations can have their IP addresses from the stanby DHCP server (top level) in case the site DHCP is not responding

I need some advices ?

I think the schema will help undersatnading my needs.

Thank you
schema-DHCP.JPG
0

DHCP

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The Dynamic Host Configuration Protocol (DHCP) is an auto configuration protocol used on IP networks and an extension of the Bootstrap Protocol. DHCP allows for computers to be configured automatically to communicate with each other over an IP network without the need for manual setup by a network administrator. The implementation of DHCP relies on a DHCP server to hand out network configuration information to DHCP-capable clients that request an IP address (and other information required or useful in communicating with other devices on an IP network). In addition to an IP address, common configuration information served over DHCP includes a default gateway, subnet mask and DNS sever(s).