ZyXEL Communications 100-NH User Manual
Chapter 8 System
NWA1000 Series User’s Guide
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as number of packets received, node port status etc. A Management Information Base (MIB) is a
collection of managed objects.SNMP itself is a simple request/response protocol based on the
manager/agent model. The manager issues a request and the agent returns responses using the
following protocol operations:
collection of managed objects.SNMP itself is a simple request/response protocol based on the
manager/agent model. The manager issues a request and the agent returns responses using the
following protocol operations:
• Get - Allows the manager to retrieve an object variable from the agent.
• GetNext - Allows the manager to retrieve the next object variable from a table or list within an
• GetNext - Allows the manager to retrieve the next object variable from a table or list within an
agent. In SNMPv1, when a manager wants to retrieve all elements of a table from an agent, it
initiates a Get operation, followed by a series of GetNext operations.
initiates a Get operation, followed by a series of GetNext operations.
• Set - Allows the manager to set values for object variables within an agent.
• Trap - Used by the agent to inform the manager of some events.
• Trap - Used by the agent to inform the manager of some events.
8.9.2 Supported MIBs
The NWA supports MIB II that is defined in RFC-1213 and RFC-1215 as well as the proprietary
ZyXEL private MIB. The purpose of the MIBs is to let administrators collect statistical data and
monitor status and performance.
ZyXEL private MIB. The purpose of the MIBs is to let administrators collect statistical data and
monitor status and performance.
8.9.3 Private-Public Certificates
When using public-key cryptology for authentication, each host has two keys. One key is public and
can be made openly available. The other key is private and must be kept secure.
can be made openly available. The other key is private and must be kept secure.
These keys work like a handwritten signature (in fact, certificates are often referred to as “digital
signatures”). Only you can write your signature exactly as it should look. When people know what
your signature looks like, they can verify whether something was signed by you, or by someone
else. In the same way, your private key “writes” your digital signature and your public key allows
people to verify whether data was signed by you, or by someone else. This process works as
follows.
signatures”). Only you can write your signature exactly as it should look. When people know what
your signature looks like, they can verify whether something was signed by you, or by someone
else. In the same way, your private key “writes” your digital signature and your public key allows
people to verify whether data was signed by you, or by someone else. This process works as
follows.
1
Tim wants to send a message to Jenny. He needs her to be sure that it comes from him, and that
the message content has not been altered by anyone else along the way. Tim generates a public
key pair (one public key and one private key).
the message content has not been altered by anyone else along the way. Tim generates a public
key pair (one public key and one private key).
2
Tim keeps the private key and makes the public key openly available. This means that anyone who
receives a message seeming to come from Tim can read it and verify whether it is really from him
or not.
receives a message seeming to come from Tim can read it and verify whether it is really from him
or not.
3
Tim uses his private key to sign the message and sends it to Jenny.
4
Jenny receives the message and uses Tim’s public key to verify it. Jenny knows that the message is
from Tim, and that although other people may have been able to read the message, no-one can
have altered it (because they cannot re-sign the message with Tim’s private key).
from Tim, and that although other people may have been able to read the message, no-one can
have altered it (because they cannot re-sign the message with Tim’s private key).
5
Additionally, Jenny uses her own private key to sign a message and Tim uses Jenny’s public key to
verify the message.
verify the message.
8.9.4 Certification Authorities
A Certification Authority (CA) issues certificates and guarantees the identity of each certificate
owner. There are commercial certification authorities like CyberTrust or VeriSign and government
owner. There are commercial certification authorities like CyberTrust or VeriSign and government