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Transmission Control Protocol/Internet Protocol (TCP/IP) is the set of networking protocols that define end-to-end connectivity specifying how data should be packeted, addressed, transmitted, routed and received at the destination. This functionality is organized into four abstraction layers which are used to sort all related protocols according to the scope of networking involved.

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hi experts,

 I changed my printers ip address and I'm on the server and trying to change the ip address and while I try to add a standard tcp/ip port I get access denied, I'm logged on as administrator. see picture
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if I disable ipv6 will it cause a problem on my network?
hi experts,

 please see screen shot, sometimes my computers get one ipv4 address and I can go online but sometimes I get TWO of them and unable to go online??
Visited a client site and ran various ‘my ip address’ site to determine what is the External IP address the provider assigned.  Noticed that each device resulted a different value.  For example their phone and their tablet gave different values where that last segment changed (xxx.xxx.xxx.19 and xxx.xxx.xxx.20), yet when we ran myipaddress in our device gave a whole different value in all segments.

We understand that the internet provider assign the cable modem or location a single dynamic external ip.  The location router managed a total different internal ip sequence values and assigns it to each device connecting to the wifi or router within the location.  Thus the cable modem has 1 IP address and the devices within the location has different ip address.

Why would the “my IP address” website display different IP address in all devices connected to the same wifi?
When adding the DNS server address of a server (and the server itself is a DNS server), is it preferable to add the IP address as "" or should the server's actual IP address of be used?

I have seen both types of IP addresses used and am wondering if there is an advantage of using one over the other or if there are any problems with using one IP address format over the other one.

This is in a Server 2016 environment.
I have regular outages when listening to an audio feed via my bowser. It just cuts out.

Is there a way for me to find out why?

Also, I got an email from my cloud back-up provider that a backup has not taken place in three days, even though my PC has been connected to the Internet the whole time.

Does anyone know of a regularly updated MAC Address Lookup resource that a person can find what MAC assignments belong to which manufacturers?
I need to add the following IP addresses to the A record of autodiscover.companyname.com within my Server 2016 AD domain:


What is the process to add all of these IP addresses to the DNS A record of autodiscover.companyname.com within my Server 2016 AD domain? All of these IP addresses need to be added, not just one.
What are the least expensive internet domain registration services?

I have a couple domain names I am interested in registering internet domain names and am looking for the least expensive way of doing this.
I need help or some guidance for the following issue.

We use a VPN connection when we connect remotely. For software installations, we use an internal web server which we have no problems connecting to when we are at work. However, I am unable to connect from home.

One of the first things I did was to traceroute the host using the LAN connection at work:
  1     1 ms     1 ms     1 ms  chlz-fw01.net.**.** []
  2     1 ms    <1 ms    <1 ms
  3    20 ms    26 ms    20 ms
  4    21 ms    20 ms    20 ms
  5    21 ms    31 ms    20 ms  xe-10-3-1-5779.******.interoute.net []
  6    21 ms    21 ms    21 ms
  7    21 ms    25 ms    21 ms

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When I connect from home with a VPN, I receive the following reply:

Tracing route to itappstore.**.** []
over a maximum of 30 hops:

  1     *        *        *     Request timed out.
  2     *        *        *     Request timed out.
  3     *        *        *     Request timed out. 

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.. and it stops after 20 hops / with the same response

Next, I used the following command:

> nslookup itappstore.**.**
Server:  itappstore.**.**

DNS request timed out.
    timeout was 2 seconds.
DNS request timed out.
    timeout was 2 seconds.
*** Request to itappstore.**.**timed-out

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So it looks like the problem might be the DNS server.

Because the IP and DNS addresses are assigned automatically,
the adapter setting won't show the addresses.

I also tried an arp command and I get the following reply
> netsh
Server:  GBLDC1-GC01.**.**

*** GBLDC1-GC01.**.** can't find netsh: Non-existent domain

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Is this a DNS issue?
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I am facing internet sharing problem in my broadband connection.I gave connection to 4 users . and each user in connect with own router . I am facing with one user cable . When i connect his cable to my broadband modem port then all users including me getting IP of this user router and no one is able to use internet . When i do unplug cable from port then Internet is working fine .

What type of problem is this ?
One of my client computers is giving us difficulty when trying to RDP into it.  I can ping the machine & get a response, where I'm confused is the IP that's returned doesn't match the host name.  I ran ping -a to check this, which returned a host name that was joined to a domain that has been decommissioned for well over 4 years.  Ran nslookup of IP it returned the same odd host name joined to the current domain.  Then I ran nslookup using the odd host name it then returned the odd host name, joined to old domain.
We have a Class C network and are running out of IP addresses.  We have multiple switches throughout our company and don't want to incur the expense of upgrading all of them to be VLAN capable.  In order to expand our addresses, is it possible to only upgrade one of our switches to a VLAN capable switch and configure it as follows:
1.) The DHCP server is plugged into one of its ports which is configured to be on the default VLAN.  
2.) Any other switch plugged into it will be plugged into a port configured to be on the default VLAN.  
3.) Any other device (printer, computer, etc.) plugged directly into it will be plugged into a port that is configured to be on a secondary VLAN.
4.)  The DHCP server is configured to hand out a different scope of addresses for devices on the secondary VLAN.
5.) The switch is configured so the VLAN's can communicate with each other.

Again, if all we need to do is expand out addresses, is it necessary that any of the other switches are VLAN capable?  Does anyone have a alternate, perhaps simpler way of expanding the addresses?  We could convert to a Class A or B network.  Please advise, and thanks in advance.
in order to configure tcp/ip you must install and enable a network adapter card server 2012 (Dell Server R430)
I am looking into using Verizon's Cellular network to gather telemetry data from remote locations. Their data is of course not free.  

I did some simple testing using a Ethernet radio link I already have and saw that to send or receive 4 bytes of actual Data i care about, takes over 170 bytes of traffic to complete the transfer. I will usually only need to gather 200 bytes of data per poll (several times per minute) and I imagine the overhead (166 bytes) will be roughly the same size whatever payload I am sending. But as I currently envision it, that's going to wind up being a third of my data fee. And that doesn't account for whatever overhead Verizon has to add just to send it through their network.

What, if any, tricks can i use to minimize the traffic?
Hi everyone

The company I am working for installs its images/OS via a network in UEFI.

How does the computer know on which server the image is stored?
Does the computer send out special packages via TCP/IP to retrieve the location of the images?
What protocol does it use?

I would also be grateful for a link to a site which explains the procedure.



 It is a small office with a windows 2012 R2 standard that is configured as a Domain Controller, DHCP, DNS and file and print server.

The DHCP scope is to
All workstations and other devices including DVR and VPN clients get their IP from DHCP dynamically or there is a reservation for them such as DVR, therefore I can see all devices under Address Leases in DHCP Console.

An annoying device seems to have dynamic IP and it is in a range of the DHCP scope ( , however the DHCP does not show it under Address Leases.
The Arp command indicates that the IP is dynamic. The Advance IP Scanner under find it but cell under NetBIOS group, User and Date are blank The only cell is the Manufacturer and MAC address. I looked around and I don’t see any device that be manufactured by NetGear and the more confusing is that when at the server I run Arp command it indicates that the IP type is Dynamic. so I must assume there is another DHCP server in the network such as router/firewall but I use SonicWall and the DHCP services is disabled.

Can anyone help please ?
what are the things to check before IP change on windows server?
How to find what all application has IP hard coded? any tools to find what all application are dependent on old IP?
Change of reverse lookup ip on pointer record and host A record and static IP on server and anything else need to be change after changing static IP on server
Hi.  We are recovering from Irma and I have noted a strange issue on a few networks where their internet went down.  The specific account I am concerned with is configured as following:
Netgear Router bridged to Comcast Modem - Router
2011 SBS Server - DNS, DHCP & AD - file sharing   IP

I have configured the workstations to use the following configurations:
LAN IP (each PC has it's own)


After setting this up on each PC, I still cannot connect to, nor ping the server or the other devices on the network.
They should be on a domain network, and they are definitely NOT home or Public at the least.

As this has happened on different networks, and the common link is they are Comcast and this has happened since we lost internet (it is popping in and out intermittently).  I just need to get the workstations to talk to the server.

Any ideas or insights?
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Google Photo's "Backup & Sync" tool is making my internet connection unusable when I'm uploading photos from my desktop.  I have another desktop & laptop, all on the same WiFi.

I do see I can limit upload and download speed.


If the desktop is the only device requesting bandwidth, I presume that would get all of the bandwidth.

However, when I start using my laptop, shouldn't it share the connection and play nice?

My Comcast is normally 30 Mbps down and 5 Mbps up when I'm not uploading.

When uploading without specifying a limit, it can drop to under 1 download and 1 upload.

I just specified a limit of 400 KB/sec and download limit to 1800 KB/sec to see if that helps.

Please explain the usage of the Multicast ip addresses below

I have seen different Multicast IP addresses used , the most common are shown below. Correct me if I am wrong : I believe this is used by the IGMP querier to  find out if there is any receiver interested in Multicast. : Probably this address is used by the IGMP querier for Auto-RP discovery (it is a little bit vague) : probably this address is used by the IGMP querier when it is configured to use PIM protocol (I am not sure if it is specific to PIM version 2 or any version) : is used by IGMP host (the Receiver) when it leaves the multicast group this is used by IGMP Version 3 receiver, But I am not sure if it is used when the receiver leaves the Multicast Group or it uses it in different circumstances . (please clarify)

Thank you
I need to register a couple internet domain names.

What are the lowest priced internet domain name registrars?
Please help me understand about ARP.
I know the local ARP table is cached and records also can be manually added. But how come when I ping a remote IP it doesn't automatically create a corresponding ARP table record?
Hello ,

I have 2 questions about timestamp ;

1. I have try to convert time stamp value to normal time but it was returned anormal dates :) what is the format of this TS val ?
2. As far as i read on the http://www.networksorcery.com/enp/protocol/tcp/option008.htm 

This field is only valid if the ACK bit is set in the TCP header.

but nearly all SYN packets in normal traffic not a DDOS has TSval  while ack was not sScreen-Shot-2017-08-27-at-18.05.41.pnget
Hello ,

Any body know a wiki that show all legal and illegal combination of tcp-flags for ipv4 ?

Thank you for the help






Transmission Control Protocol/Internet Protocol (TCP/IP) is the set of networking protocols that define end-to-end connectivity specifying how data should be packeted, addressed, transmitted, routed and received at the destination. This functionality is organized into four abstraction layers which are used to sort all related protocols according to the scope of networking involved.