|
|
This is only a preview of the paper
Click here to register and get the full text.
Existing members click here to login
|
|
|
1
APPLICATION
DNS: THE DOMAIN NAME SYSTEM
Programs rarely refer to hosts, mailboxes and other resources
either in binary or in decimal address format. ...
Nevertheless, the network protocol can only understand binary
addresses. ... They contain
1. ... Delivery is
accomplished by having the non-Internet site make an
arrangement with some Internet site to accept email for it and
forward it using whatever the protocol the two of them agree on. ... 86400 IN MX 1 zephyr. ... 86400 IN MX 1 flits. ... 201
IN MX 1 rowboat
IN MX 2 zephyr
IN HINFO Sun Unix
little-sister IN A 130. ...
7
SNMP- SIMPLE NETWORK MANAGEMENT
PROTOCOL
In early days of the ARPANET, if the delay to some host became
unexpected large, the person detecting the problem would just run the
ping program to analyse the packet delay. ... In May 1990, RFC 1157 was published the definition of
SNMP (Simple Network Management Protocol) Version 1. ...
The SNMP Model:
The SNMP model of a managed network consists of four components:
1. ... A management Protocol
Managed nodes can be hosts, routers, bridges, printers or any other
devices capable of communicating status information to the outside
world. ...
The management station interacts with the agent using SNMP protocol. ...
SNMP AND ASN.1
9
The heart of the SNMP model is the set of objects managed by the agent. ... To
achieve this goal, ASN.1 is used.
SNMP has some lexical conventions that are not entirely the same as pure
ASN.1. The basic ASN.1 data types allowed in SNMP are as follows:
Primitive type Meaning Code
INTEGER Arbitrary length integer 2
BIT STRING A string of 0 or more bits 3
OCTET STRING A string of 0 or more
unsigned byte
4
NULL A place holder 5
OBJECT IDENTIFIER An officially defined data
type
6
OBJECT IDENTIFIER provides a way of identifying objects. ...
10
PART OF ASN.1 OBJECT NAMING TREE
In the above figure, every arc has both a label and a number. ... Thus all SNMP
MIB objects are identified by a label of the form:
{ISO identified-organization(3)dod(6)internet(1)
}
or alternatively they can just be identified as:
{1,3,6,1
. ...
We can use ASN.1 to create new types from the basic one. This is by
using
1. ... CHOICE
ASN.1 defines a complex macro mechanism, which is heavily used in
SNMP. ...
SMI: STRUCTURE OF MANAGEMENT INFORMATION
Here we discuss the part of ASN.1 which are used in SNMP. ... For example, if a router has lost exactly 232 packets, rather
than reporting 0 (as like counters, they go full round and come to 0), it is
better to report as 232 1. ... This information was moved to protocol specific MIB in
SNMPv2. ...
The EGP group is used for routers that support the exterior gateway
protocol. ...
15
THE SNMP PROTOCOL:
In SNMP protocol, the management station sends a request to an agent
asking for specific information, or issues a command to update its state in
a certain way. ... Data are
sent using the ASN.1 transfer syntax.
Approximate Word count = 2867
Approximate Pages = 11.5
(250 words per page double spaced)
|
|
|
|
|
|