Questions tagged [dhcp]
For questions about DHCP in in relation to network devices. For instance, you are setting up DHCP on a layer 3 switch.
462 questions
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DHCP server on a Juniper MX5
I'm trying to configure a basic DHCP server on a Juniper MX5. Although I have a significant experience of configuring DHCP servers on a branch Juniper devices, the standard approach mysteriously doesn'...
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CBS350-24XS problem with ip obtain by DHCP pool for IP phones
I have problems with obtaining IP address by DHCP server which configured on CBS350-24XS switch.Problem happens only with IP phones : Cisco SPA504G,Fanvil X3S.
Firmware version is latest : 3.3.0.16
I ...
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can DHCP server Detect type of windows? [duplicate]
I have a DHCP server and several clients, some running Windows 10 and some Windows 7. I want the DHCP server to be able to identify the Windows version of the clients using the vendor class and assign ...
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How to configure DHCP on CISCO IOS XE with options (60) conditions?
Cisco IOS XE Fuji 16.9:
How can I make the client receive the "bootfile" option, depending on what is specified in "option 60"?
This is necessary in order to transfer the necessary ...
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Juniper and EdgeCore dhcpv6-relay remote-id (option 37)
I have the following problem. I have minimal configuration of dhcpv6-relay agent on QFX5100. Before the QFX, there is an Edgecore switch on which DHCPv6 snooping is enabled. The problem occurs as soon ...
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How is routing precedence determined in DHCP Offer and Acknowledgement packet from server?
I'm learning about the DORA process in TCP IP. And the way server communicates with client is very "confusing" to me.
Let's take an example of DHCP Offer:
At this point, the client is still ...
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DORA process TCPIP [duplicate]
http://www.tcpipguide.com/free/t_DHCPGeneralOperationandClientFiniteStateMachine.htm
I'm reading through the entire Discover, Offer, Request, Acknowledgement phases in DHCP. And I am really confused. ...
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Cisco catalyst 6500 not assigning static dhcp assignments to a couple of devices
in the following question cisco catalyst 6500 not honoring static ip assignments I had been able to get 16 out of the 20 devices im working with to honor the static ip settings. 4 devices are for ...
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cisco catalyst 6500 not honoring static ip assignments
I have a catalyst 6500 sup720 running 15.1(2)sy6 and i have attempted to have a set of mac addresses to get a specific ip from dhcp. below is what shows on the bindings.
10.1.4.200 01e0.508b....
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DHCP packets in a Wi-Fi network (WEP2-Personal)
The DHCP packets with the message type Discover, Offer, Request and Acknowledge use the L2 broadcast address for communication (even in the Acknowledge packet which has an IP destination of the newly ...
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ASA 5555 loses internet connectivity every few days, problem resolves by re-enabling DHCP on wan interface
I'm having a weird problem with my ASA. Every few days the internet connectivity fails (f.e. cannot ping wan ip addresses from the ASA). Problem resolves by forcibly rebinding the DHCP by no ip ...
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Cannot get my servers on the same broadcast domain as backbone gateway using Aruba switches [closed]
My supervisor told me to go to the server room and connect a bunch of servers to the Department network so they are accessible from office PCs. In the server room we have 7 servers, a couple of wall ...
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DHCP Client Traffic not going through IRB interface as expected
I have several Juniper EX4300 series switches that I'm trying to configure to meet the following specifications:
I'd like each switch to manage a /24 DHCP pool that corresponds to a rack
I'd like ...
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DHCP - General relativity
The following image shows a visualization of the DHCP server in action. DHCP servers send a DHCPNACK message in a scenario where the same ip address is trying to be assigned to 2 devices. Is this ...
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DHCP request for multiple IPs at once [closed]
In DHCP, a DHCP client and a DHCP server go through the protocol exchange (DISCOVER, OFFER, REQUEST, ACK) so that the client ends up with an IP address allocated to it that is also tracked in the ...
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Dhp L2TP reservation on cisco 1921
I use a Cisco 1921 as L2TP server.
(I don't want to use RADIUS authentication.)
Please is someone can tell me how is it possible to do IP reservation, using client identification?
I have tried dhcp ...
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CISCO 9800-L Controller internal dhcp not working - GUEST WIFI
I have been trying to configure a guest network for my Cisco Catalyst 9800-L Wireless Controller for some days now. For the guest network, i want it to use an internal dhcp on the controller. I have ...
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bandwidth on WAN link
I would like to understand how a router is able to divide bandwidth among users who are using the same WAN link.
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No access to internet via DHCP, but works with manual IPs
My DHCP server was giving out IPs in the range 10.0.0.1/24, but I ran out of usable IPs, so I changed the subnet to 10.0.1/21 to have more available addresses, however I am now having a weird problem:
...
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IPSec over L2GRE scenario
I wanted to know if this is a valid scenario and if it is possible to implement.
There is a remote site A. and a Data center site B. Both A and B have a edge router which runs an IPSec tunnel. An ...
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Does this DHCP Server need a trusted ARP Inspection port in IOS?
The switch runs Cisco IOS. You want to configure security on Switch 1. The objective is configuring Dynamic ARP Inspection on Switch 1. Which Ports or port will you configure as Trusted?
A) None of ...
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HSRP and DHCP problem
I have 2 layer 3 switches DS1 and DS2. There are the same VLANs but different IP addresses on VLAN interfaces.
On DS1:
VLAN 10: 192.168.10.1/24
VLAN 20: 192.168.20.1/24
On DS2:
VLAN 10: 192.168.10.2/...
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Do Directly Connected Routers Need Routing Protocols For DHCP Relay To Work?
Let us say that we have R01, R02, and R03 connected to each other, and each of them is connected to a different subnet SUB01, SUB02, and SUB03, respectively. R03 is set up as a DHCP server, and DHCP ...
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can a layer 2 switch block dhcp from 1 port, both in and out?
Here's what I want to do: "Wall" is the dhcp server from the ISP. "R" is my internal router. "L2" is a hypothetical switch. "fs" is my dhcp server. I want ...
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CISCO cellular Router cannot reach network via my PC
I configured the cellular and my router is connected to the internet ping (5/5) Success
but I still cannot access the internet via PC
Here is my running-conf
Current configuration : 2271 bytes
!
! ...
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What does 'CPE' stand for, and what is it?
In reading up on NextDNS, I came across the add-cpe-id option to dnsmasq:
--add-cpe-id=
Add an arbitrary identifying string to DNS queries which are forwarded upstream.
NextDNS uses this for your '...
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Which device gets the helper-address?
Brand new to networking and trying different scenarios.
PC2 can successfully send packets to PC1 and the DHCP server if a static address is assigned. However, PC2 will not obtain a DHCP address from ...
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Cisco Switch vIOS-L2 in GNS3 and CCNA 200-301
I am reading a preparation book for the CCNA Test 200-301. Currently, I am reading a section about DHCP and VLAN interfaces in a switch. The book shows an example of configuring this.
switch# ...
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Inconsistent behavior of show ip dhcp pool poolname
show ip dhcp pool Mitarbeiter10 gives the following output:
R1#show ip dhcp pool Mitarbeiter10
Pool Mitarbeiter10 :
Utilization mark (high/low) : 100 / 0
Subnet size (first/next) : 0 / 0
...
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How do I configure a Cisco router to relay DHCP packets to DHCP server on the basis of different VLAN?
Running-Config of RO1
!
interface GigabitEthernet0/0
ip address 192.168.25.26 255.255.255.0
duplex auto
speed auto
!
interface GigabitEthernet0/1
no ip address
duplex auto
speed auto
!
interface ...
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UniFi6 LR access points go into scan loop [closed]
I have a Ubiquiti setup with four Unifi 6LR access points. I manage to adopt them in the controller just fine and I do briefly see the wifi come up, but then it immediately drops. SSH'ing into the ...
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Trusted and Untrusted ports in DHCP Snooping / ARP Inspection
From a networking course I am following, I've learned that in D. ARP Inspection, ports connected to routers or to other switches should be configured as trusted while the user ports should remain ...
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Why my PCs can't get dynamic IPs from DHCP Server?
In Cisco Packet Tracer I created following network
Following is how I configured the DHCP Server
But the computers can't get IP addresses - getting "DHCP failed" message. Why? Please ...
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How to correctly setup a DHCP server in the following network?
So, I've got the following Network Configuration:
Assume that, on the graph, "PCs" can be any device that needs an IP(apart from a router).
Now, as explained on my title, I want to run a ...
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Lost the Static IP/network settings of a device
We have a physical device (lab instrument) that we can only connect to via ethernet. Unfortunately a static IP was set with network settings and these settings has been lost.
We connected our computer ...
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DHCP RELAY AGENT NOT WORKING TO USER(apipa failed)
can someone help me to solved my router 1 as relay agent dhcp.Currently user 5 that connect from switch 1 is not being able to get dhcp ip address.
My router 2 as dhcp server pool and user 3 ,4 is ...
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Can a router provide DHCP to multiple subnets that are connected via switches?
I'm trying to understand if it is possible to have a router (as shown in the below diagram) provide DHCP leases to more than one subnet if the subnets are not directly attached.
If both the printers ...
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Is DHCP in the application layer or the network layer?
Tanenbaum's Computer Networks says:
5.6 THE NETWORK LAYER IN THE INTERNET
...
5.6.4 Internet Control Protocols
In addition to IP, which is used for data transfer, the Internet has
several companion ...
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DHCP Discover Broadcast and its IP (255.255.255) [duplicate]
Cheers, I am trying to learn more about DHCP, and when studying about the session that DHCP goes through every one mentions that it broadcasts a discover message at IP: (255.255.255.255) (as seen here ...
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How to configure a router as a dhcp server for vlans through a Layer 3 switch?
I would like to know what commands to type in the different switches and the router to to make the router function as a dhcp server for each PC in seperate vlans .
I know to create the dhcp pools in ...
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What could be the bottleneck of my load-testing case?
I need to bring up a bunch of my devices in the network to hit some other service, for testing purposes. And I have used GNS3 to simulate that.
As you may find in my GNS3 project, I have such ...
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Question about subinterface DHCP relay CISCO
I want to make 4 PC got DHCP IP address
No problem with left side, but right side 2 PC can't get IP automaitic. I think the problem is DHCP Relay.
How can I use ip helper-address for subinterface of ...
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Is there an equivalent of the Cisco/ Cisco esque command "ip helper-address a.b.c.d" on Mellanox switches?
Apologies for my newbie question. I have recently had a Mellanox switch added to the mix. I was using an "IP helper-address" to forward DHCP requests in different VLANs to my DHCP server(s) ...
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How does DHCP work?
I'm carrying out an experiment to test the mechanism behind DHCP.
In this topology, I disable the link between the switch and the router. However, the computer still request IP address successfully.
...
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644
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How does a DHCP server know which network interface and subnet the new IP address should be on
I've read that DHCP servers add a column to your iptable in your router. A new dynamically created IP address with a network interface and a subnet mask. Then the IP address is matched with your MAC ...
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How can u assign IP addressing for point to multipoint switches that connect to only one router?
I was wondering if I can assign two network address in a LAN while the switches are point to multipoint which connect to only one router.
How will me DHCP going?
Router - Switch 1 - Switch 2,3,4
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how to configure dnsmasq client-identifier for juniper prefix host-name
I have a Juniper switch that has a dhcp-client configured like this:
show interfaces irb unit 0 family inet dhcp
client-identifier {
prefix {
host-name;
}
}
I ...
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Apply Interface Default Gateway to Entire Device
I feel there may be a very simple term for what I trying to do, but I'm not sure what it is, and it is difficult to search for it in concise words.
The shortest description I can come up with: "I ...
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670
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Configuration of DHCP for multiple vlans
I have the following network on Packet Tracer. The hosts are in different vlans each one. My goal is that the DHCP server can give IP to the hosts.
Here is what I made for each vlan (the example is ...
user80646
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Do IPv6 addresses have better persistence with DHCPv6?
I have a LAN with about 25 devices that occasionally grab each other's IP address via DHCPv4. I know there are certain lease time limits and it can be set to very long periods to work it around to an ...
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