topic How to explain Source IP Address, Destination IP Address & Service in easy way in Network Security

How to explain Source IP Address, Destination IP Address & Service in easy way

Adam David — Mon, 11 Mar 2019 17:55:30 GMT

Hi,

These three terms are common for network & firewall guy. However others who are not working in this are normally doesn’t really know what is the meaning of this terms.

The problem start when people requesting to open certain network port from certain source to certain destination. However, they don’t really understand what of the meaning of this terms even though we've prepared proper form for them to fill up these informations. Sometimes, they put destination at source column and always forget to put either TCP/UDP. Normally they only put the number of the ports. Here is the example of the form.

	Source IP	Destination IP	Service (TCP/UDP)	Port Number
1
2
3

Therefore, I would appreciate if anyone can share how to explain these terms in easy way especially to those who didn’t have knowledge in networking.

Thanks.

Re: How to explain Source IP Address, Destination IP Address & S

andrew.prince — Mon, 07 Jun 2010 08:03:57 GMT

When using a document - that is the easiest way. I find the best way is to have a conversation with the remote person.

Re: How to explain Source IP Address, Destination IP Address & S

Jon Marshall — Mon, 07 Jun 2010 18:54:49 GMT

netw0rker wrote:

Hi,

	Source IP	Destination IP	Service (TCP/UDP)	Port Number
1
2
3

Therefore, I would appreciate if anyone can share how to explain these terms in easy way especially to those who didn’t have knowledge in networking.

Thanks.

Adam

Firstly having colums for both service and port number is unnecessary as far as i can see. You could ask for either service name/port number in the same column,

Secondly it really depends on who is filling in this document. Your average user does not differentiate between TCP/UDP. Even source IP, destination IP can be asking too much. Perhaps try -

IP address of machine you are coming from

IP address of machine you are trying to connect to or more likely URL

Jon

Re: How to explain Source IP Address, Destination IP Address & S

Adam David — Fri, 18 Jun 2010 11:07:39 GMT

Thanks Andrew & Jon for your reply.

Yes, I know we can combine columns for both service and port number. However user tend to forget to fill up whether the service is tcp or udp. They only provide the ports number.

How about services/network ports? Do you have any idea how to explain it in a easy way?

Here is the definition that I get from wiki, however I believe that person who don’t have background in networking will have a problem to understand it.

According to IANA "The Well Known Ports are assigned by the IANA and on most systems can only be used by system (or root) processes or by programs executed by privileged users. Ports are used in the TCP [RFC793] to name the ends of logical connections which carry long term conversations. For the purpose of providing services to unknown callers, a service contact port is defined. This list specifies the port used by the server process as its contact port. The contact port is sometimes called the "well-known port"."^[1]

http://en.wikipedia.org/wiki/List_of_TCP_and_UDP_port_numbers

Re: How to explain Source IP Address, Destination IP Address & S

Jon Marshall — Fri, 18 Jun 2010 17:32:56 GMT

netw0rker wrote:

Thanks Andrew & Jon for your reply.

Yes, I know we can combine columns for both service and port number. However user tend to forget to fill up whether the service is tcp or udp. They only provide the ports number.

How about services/network ports? Do you have any idea how to explain it in a easy way?

Adam

The service/port number is one of the things that an average user will have no idea about ie. they just fire up their application and it either works or it doesn't.

Best thing you can do is to ask for port number/application in use. Often it's better to just ask what are you trying to do ie. what are you using on your computer eg. web browser, specific desktop application and then you do a bit of detective work.

But don't be surprised if this column is often left blank because your average just doesn't know this sort of info.

Jon