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What is NAT (Network Address Translation) use for, function and use for what?
What is SAP stands for, function and use for what?
What is SNMP use for, function and use for what?
How about IP filtering?
(Network Address Translation) An IETF standard that allows an organization to present itself to the Internet with one address. NAT converts the address of each LAN node into one IP address for the Internet and vice versa. It also serves as a firewall by keeping individual IP addresses hidden from the outside world.
For the Next one I included SIP because it ties into SAP:
(1) (Session Announcement Protocol) An IETF protocol for distributing session description messages to potential recipients. It is widely used to send SDP messages.
(Session Initiation Protocol) An IP telephony signaling protocol developed by the IETF. SIP is a text-based protocol that is based on HTTP and MIME, which makes it suitable and very flexible for integratedvoice-data applications. SIP is designed for voice transmission, uses fewer resources and is considerably less complex than H.323. Its addressing scheme is URL-like and human readable; for example: sip:john.doe@company.com. SIP relies on the sessiondescription protocol (see SDP) for session initiation. Windows XP was the first version of Windows to natively support SIP.
(Simple Network Management Protocol) A widely used network monitoring and control protocol. Data is passed from SNMP agents, which are hardware and/or software processes reporting activity in each network device (hub, router, bridge, etc.) to the workstation console used to oversee the network. The agents return information contained in a MIB (Management Information Base), which is a data structure that defines what is obtainable from the device and what can be controlled (turned off, on, etc.). Originating in the UNIX community, SNMP has become widely used on all major platforms.
SNMP 2 provides enhancements including security and an RMON (Remote Monitoring) MIB, which provides continuous feedback without having to be queried by the SNMP console.
by jaboy78
Here is an address that will tell everything you want to know about NAT:
http://www.vicomsoft.com/index.html?page=http://www.vicomsoft.com/knowledge/reference/nat.html*track=internal
SAP basically every 30-60 seconds each resource on the NetWarenetwork shout to the rest of the network "I'm here!". In network with only one or two servers it might be okay, but imagine the traffic on a network with a fair number of servers. On small to medium networks with a few servers this will work, but on a large network the volume of broadcasts flooding the network makes the ssystem unworkable. Another reason periodic advertisment doesn't work well is that networks of any size are divided into segments, with the segments connected with routers that can identify where the segment traffic goes to. Routers move messages from one segment to another and are smart enough to avoid retransmitting messages unnecessarily. This cuts down on network congestion, but routers generally do not retransmit broadcast messages, which means SAP broadcasts don't get sent to other segments.
SNMP - An SNMP-managed network consists of three key components: managed devices, agents, and network-management systems (NMSs).
A managed device is a network node that contains an SNMP agent and that resides on a managed network. Managed devicescollect and store management information and make this information available to NMSs using SNMP. Managed devices, sometimes called network elements, can be routers and access servers, switches and bridges, hubs, computer hosts, or printers.
An agent is a network-management software module that resides in a managed device. An agent has local knowledge of management information and translates that information into a form compatible with SNMP.
An NMS executes applications that monitor and control managed devices. NMSs provide the bulk of the processing and memory resources required for network management. One or more NMSs must exist on any managed network.
For More information on SNMP visit:
http://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/snmp.htm#xtocid1
IP filtering is simply a mechanism that decides which types of IP datagrams will be processed normally and which will be discarded. By discarded we mean that the datagram is deleted and completely ignored, as if it had never been received. You can apply many different sorts of criteria to determine which datagrams you wish to filter; some examples of these are:
Protocol type: TCP, UDP, ICMP, etc.
Socket number (for TCP/UPD)
Datagram type: SYN/ACK, data, ICMP Echo Request, etc.
Datagram source address: where it came from
Datagram destination address: where it is going to
It is important to understand at this point that IP filtering is a network layer facility. This means it doesn't understand anything about the application using the network connections, only about the connections themselves. For example, you may deny users access to your internal network on the default telnet port, but if you rely on IP filtering alone, you can't stop them from using the telnet program with a port that you do allow to pass trhough your firewall. You can prevent this sort of problem by using proxy servers for each service that you allow across your firewall. The proxy servers understand the application they were designed to proxy and cantherefore prevent abuses, such as using the telnet program to get past a firewall by using the World Wide Web port. If your firewall supports a World Wide Web proxy, their telnet connection will always be answered by the proxy and will allow only HTTP requests to pass. A large number of proxy-server programs exist. Some are free software and many others are commercial products.
by jaboy78
by jaboy78
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