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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I just enabled DNS-Over-HTTPS in my google chrome and wanted to know how to set it in the iPhone/iPad.   Haven't been able to do ti; how can I enable DoH in my iPhone/iPad?
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I have (2) Watchguard M270's configured in a firecluster.

Interface 0 is the External interface configured with a /28 block.
Interface 1 is the LAN

We have consumed all of our IP's so I ordered another /28 block from our datacenter today. As soon as I configure Interface 2 for our new IP block, outbound traffic for the most part ceases to work on our network, however some things do work.. so we'll call it intermittent. As an example, I can ping out to but can't ping As soon as I disable Interface 2 that is configured for the new IP block, I am able to ping again.

I'm assuming this is because we now have 2 WAN interfaces configured and outbound traffic doesn't know which interface it should be sending traffic out on but I couldn't be sure. I've made 4 calls to Watchguard support and nobody can identify the problem. I even had our datacenter issue us a different IP block just to rule out any kind of odd conflict but the problem persists with a new IP block.

Am I going about this all wrong trying to have 2 IP block's configured on our Watchguard? Is the better solution to just order a bigger block of IP's and re-IP everything? I was trying to avoid that hassle by just adding an additional block of IP addresses but it seems that what I'm trying to do here isn't working..

I would appreciate any advice or input that someone could give on this. Thank you!!

My site has not stopped planting for a while.
I was advised to check my logs and I see that there is this IP 150.918 times in my logs from 00:00:07am to 12:36:01am

what do you advise me to do?

I added this Deny from to my .htaccess but ip continues to show...

Thank you for your advice,
I have an electronics board which has 16 relays and it works over TCP/IP.
The IP address of the board is and the port is 3000.
I would like to control it with C/C++ under Ubuntu.

There is a list of HEX commands that it is possible to use in order to remotely switch ON and OFF each relay on the board.
This is the list:
"580112000000016C",  // switch on the relay 1

"580111000000016B",  // switch off the relay 1
"580112000000026D", // switch on the relay 2
"580111000000026C", // switch off the relay 2
"580112000000036E", // so on..

I'm correctly able to switch on and off each relay by sending command line commands under Ubuntu:

echo '580112000000016C' | xxd -r -p | nc 3000

Open in new window

The above code correctly turns on the relay.

I would like to do the same with C/C++ code since I want to control the …
I have 2 PCs that are both connected to the same WiFi network.  Both PCs are on the same work network, both have the same workgroup name and I have toggled network sharing off and on - on both of the devices.

Neither can ping the other.  However, where it gets strange here... If I run simultaneous cmd pings of each other, #1 PC starts successfully pinging the other, but stops if I stop the ping attempts from the other PC to it.  #2 PC pings never resolve.

Both devices are Dell Optiplex 3030AIO and on Windows 7 Pro, Service Pack 1

All the Servers are in Data Center (Colo).
I want to go remotely to all the Controllers (including IDRAG) which are in Colo.

Question: What command would I use to get the above IP addresses?

I'm having issues finding IP address design plans to implement in a newly deployed network.  Running BGP at the Edge and OSPF as an IGP.  Any assistance is greatly appreciated.
I have two NICs, one is cabled directly into a server, and the other goes through a Sonicwall and out to the internet where it sends and receives files from a central portal.

The NIC to the server is working fine.

The NIC to the internet is saying "Limited" and I cannot get full connectivity for that NIC, can anyone please advise on how to troubleshoot a NIC that is giving this error
My network is not allowing me to see all the network devices using windows 10, I see some of the devices.  My MAC however see all the Network devices.  I have a server WIN 2012 server and it see some of the devices in the network.  We are using a Workgroup environment connect to Office 365.  Some machines are connected to the Work and School and some are not.
My main problem is a NAS server that is on the same subnet but I cannot get it to be discovered when I use the IP address of the NAS server?  I have 2 NAS servers and both are very difficult to connect to?   I took over this network and the previous Admin used a lot of VLAN configurations, can he controlled the network using th vlan on the switches?

I looking at the router, I looking at the switches....I not sure where exactly to start and try to identify the lag in the network and why I cannot see the other devices?
Can someone help me determine how to find out where the IP address of lives on my network. It appears to be a webpage. I'd like to turn it off with the abillity to turn it back on, then see if anyone complains that they are missing something

Message meets Alert condition
Virus/Worm detected: HTML/Framer.INF!tr Protocol: "HTTP" Email Address From:  Email Address To:
date=2019-08-02 time=09:04:13 devname=FG-Corporate devid=FG100D3G14808552 logid="0211008192" type="utm" subtype="virus" eventtype="infected" level="warning" vd="root" eventtime=1564751053 msg="File is infected." action="blocked" service="HTTP" sessionid=106413455 srcip= dstip= srcport=49975 dstport=80 srcintf="lan" srcintfrole="undefined" dstintf="wan1" dstintfrole="undefined" policyid=92 proto=6 direction="incoming" quarskip="File-was-not-quarantined." virus="HTML/Framer.INF!tr" dtype="Virus" ref="" virusid=8054799 url="" profile="default" agent="Mozilla/5.0" analyticscksum="0a449968f2e6c0c358cecf9365b94041399735926a25573e1e37fbdb4e741f05" analyticssubmit="false" crscore=50 crlevel="critical"
Exploring ASP.NET Core: Fundamentals
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Exploring ASP.NET Core: Fundamentals

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We have multiple sites all on different subnets, we have one central DHCP server which I want to change (so I can do maintenance).

I want to add a second DHCP server (for redundancy) but I can only broadcast one helper address from the site routers.  I have read up on virtual IP's but am unsure if this is the correct way to go.

We have multiple DC's in different geographical locations
Routers are part of our MPLS so I cannot make changes (I can have the helper add changed)
All servers are in the hosted data center (VM's)

All help/advice gratefully received.
Usage of Update-Source Loopback X

I have seen in BGP configuration where they configure : Neighbor x.x.x.x remote-as x  Update-Source Loopback X
Even if there is only one path to reach the neighbor
for instance in the topology below, let's take R5 with R1 as example:

R5: Neighbor remote-as 1 update source loopback 0

instead of Neighbor 51.0.01 remote-as 1

assuming R5 s1/0= and R1 s1/2 =

Thank you

BGP Configuration with and without another IGP

in the topology below, I would like to know if :

-- BGP needs to be configured on R1  R2,R3,R4  without any other IGP (OSPF)configured on the same routers.
-- Or BGP can be configured only on R1 and R4, but IGP (OSPF) should be configured on all 4 routers R1,R2,R3,R4


OSPF Address-Family

I have seen  in some examples EIGRP configured with   address-family ipv4 vrf <VRF Name>  autonomous-system <AS Number>
However I have not seen examples where OSPF  is configured with  address-family ipv4 vrf <VRF Name>

for instance, in the topology below Customer Edge CB_1 uses OSPF  and  it is connect to PE_1


Configuring BGP at the Customer Edge Router

knowing that Customer Edge routers cannot contain in their tables all BGP routes available in the Internet, so how are those Customer edge routers configured to reach Internet without having to have full internet routing table

Thank you

Currently we are trying to utilize PXE boot across subsets in our environment. Please read below for more information

Current network environment:
●      The USG Router and Switches are assigned static IP addresses listed above
●      The USG router has networks/vlans created on them via the UBNT controller UI (v5.10.23.0)
●      The USG Router is responsible for DHCP for each network
●      Our WDS/MDT server is sitting on vlan 100
●      We are able to PXEboot clients on the same subnet (10.10.1.x/24)
●      Issue: We are trying to have clients on the Techbench network vlan 3340 be able to communicate pxe boot to our wds server (

Current settings in DHCP TechBench4 network
Advanced DHCP Options:
Error on Client machine:
I will soon place wireshark traffic logs when i finish testing:
Need to SSH to my AWS Ubuntu server from Mac Terminal

I opened Terminal, executed
sudo su (to become super user)

changed directories so that my current folder shows my KeyPair1.pem file and when I execute

ls - l

I see my .pem file has the following permissions:


please explain this. It's Read access for who exactly?

I ran "chmod 400 KeyPair1.pem" as a way to protect the file from being over-written, Is this the correct thing to do?

I have the IP address of my Ubuntu server:

I execute the same command provided by AWS, but find the terminal locks. I am forced to press Ctrl+C to get the cursor again:

ssh -i "KeyPair1.pem" ubuntu@

Does anyone see what's wrong?

When I type ssh <ENTER> I get:
usage: ssh [-46******************Yy] [-B bind_interface]
           [-b bind_address] [-c cipher_spec] [-D [bind_address:]port]
           [-E log_file] [-e escape_char] [-F configfile] [-I pkcs11]
           [-i identity_file] [-J [user@]host[:port]] [-L address]
           [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]
           [-Q query_option] [-R address] [-S ctl_path] [-W host:port]
           [-w local_tun[:remote_tun]] destination [command]

Does this mean SSH is installed?

Is there a way to see what variant of SSH is installed?

IP Subnetting

I have this  Prefix , If I am not wrong  this will cover to
OK, if I will have to demonstrate that using binary, how can I do that  ?
224 = 1110 0000 then the rest is  0000 0000 . 0000 0000 . 0000 0000

so where does the /4 belong there ?

Thank you
My questions are about re-linking the kernel and rebuilding the kernel environment.
What does "rebuilding the kernel environment do"?
Is it required when re-linking the kernel?
How can I boot the old kernel if the new kernel fails, or has some wrong behavior?

I am afraid what will happen if the new kernel won't boot, or if there is erratic behavior with the new kernel.
How can I boot the previous kernel that was working fine?
Will the old kernel have trouble if I said "yes" to rebuild the kernel environment when creating the new kernel?

NOTE:  I see this when unix boots if I wait 60 seconds, or hit the enter key

OpenServer Release 5
hd(40)unix swap=hd(41) dump=hd(41) root=hd(42) auto

Sizing memory
....................  many rows of dots

I suspect that during the 60 second wait, I can type something to invoke the old kernel.
What do I type?
I have not found any documentation on this in man boot(HW)

Why am I doing this?
I have SCO OpenServer 5.0.7 Host Edition with Maintenance Pack 5
Host Edition does not include Networking.
Enterprise Edition is needed for networking.

I don't know why, but I have some network components on the server.
Perhaps they were installed by Maintenance Pack 5
inetd and ftpd are running every time the system starts.

I tried to add the Intel PRO 1000 LAN adapter with TCP/IP.
I was prompted to re-link the kernel.
I hedged.
I can't afford to end up with a system I can't boot.
I need to know if I can get …
OWASP: Threats Fundamentals
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OWASP: Threats Fundamentals

Learn the top ten threats that are present in modern web-application development and how to protect your business from them.

Ethernet/IP EIP
TCP/IP Modbus

My private network
I am trying to exclude a specific ip address from being assign to any Ec2 when rebooting or provisioning a new instance.
Reason.  We have disaster recovery in AWS and auto generate an instance with a specific private ip address  that we need to have available when the instance spins up.
I want to forward my TCP/IP port 1433 properly to the local workstations, so far I'm now at Enable port forwarding and connect

Steps taken so far

Enable port forwarding and connect

Create a new port forwarding I have noticed that each router is different. But the goal is the same: Enable the Port Forwarding on your router.

To do that, I have done this see below :

– Login to the router
– Search WAN Services
– And create Port forwarding with this informations:
   • Name : Name for this rule (example SQLExpose)
   • Protocole: TCP/UDP
   • WAN port: 1433
   • LAN port: 1433
   • Destination IP:

(1)      On the Destination IP what do I put there??? Is it the host server IP Public address  or Local workstation IP Public Address??????
(2)       At this point since the server is already configured to enable port 1433 can the machines on LAN work??
(3)      What about those on a secure network (VPN) as per above setting can the machines work?

See picture also


This is one of the toughest area I’m encountering so far, they are just too many rules, anyway further advice or notes will be appreciated it’s a learning curve.


Should the SQL Server connection string change also when connecting over the internet what I mean is people will have to input data through workstations that may be dotted in some different countries,( This is after configuring the firewall & enabling TCP/IP)

Let us assume the workstation is in the USA and its static IP Public address is and the host SQL Server is in the UK with static IP Public address now we want to ensure that a person using a workstation in the USA is able to update data in the UK SQL Server ( without problem. Assuming  the following is done correctly

(1) TCP/IP properly enable and port 1433 forwarded  to host IP address  and also the workstation in the USA is linked to 1433 to

   Example : Port Range Forwarding (UK Modem)

                      Application                     Start                 End                       Protocol                          IP Address            Enabled
                      Sql                                    1433                1433                      Both                             Ticked

Example : Port Range Forwarding (USA Modem)

                      Application                     Start                 End                       Protocol                          IP Address            Enabled
                      Sql                                    1433                1433      …
How can I forward the port I opened 1433 to the router, this is after all the below steps were followed:

(1)      In order to allow access to SQL Server instance, I had to enable TCP/IP protocol which is not enabled by default
(2)      From the SQL Server Network Configuration node, I selected the Protocols item for the appropriate SQL Server. In the details pane, I right clicked the TCP/IP item and select the Enable option:
(3)      In order for the changes take effect, from console pane, I selected the SQL Server Services and from the details pane, I right clicked the SQL Server (SQLEXPRESS) database engine instance and click the Restart option:
(4)      Now after the above steps I had to configure the windows firewall as follows:
(5)      From the Control Panel I choose Windows Firewall and clicked the Advanced settings
(6)      In the Windows Firewall with Advanced Security, I clicked the Inbound Rules from the left pane, I right clicked Inbound Rules and select the New Rule, Under the Rule Type I choose Port and click the Next button:
(7)      I now selected the UDP protocol and in the Specific local ports entered port number 1434. To proceed with the settings SQL Browser services, I clicked the Next button:
(8)      Then a dialog box popped up then I choose in the Action dialog choose Allow the connection and clicked the Next button:
(9)      Then there was another dialog box in the Profile dialog I choose all three profiles (Domain, private & public) and click the Next button:
(10)       Then I clicked …
This gist:
I need to redirect a wide range of ports (or all, if possible) to a remote server to support clients that are slow to re-resolve DNS. Any recommendations that are compatible with Ubuntu? I'm also open to Windows based solutions (if there's something easier available on Windows).

I am planning to move a server that communicates with field devices (remote clients initiate the connections) from one provider to another.

Once the server is ready I will change the DNS record to point to the new server, however, experience with our field devices tells me that I can't rely on them all to resolve the new address.

I'd like to see what software TCP redirect options there are. I've actually tested with RINETD in the past and a couple of other solutions that I can't remember off the top of my head, but only a couple of ports/devices at a time.

The traffic is constant but lightweight. Mostly ASCII commands and event data, from ~150 endpoints.

Thanks for any suggestions.






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.