应用场景：
在管理Agent设备的配置文件的时候，难免会遇到增删查改的操作。一般的snmpget对应查，snmpset对应改，但是增删就不是简单的直接操作了，就需要用到今天的主角——RowStatus这个属性。
小坑一个：RowStatus一定是和Table一起用的。
传送门：官方文档，喜欢阅读官方文档的朋友不容错过，不过是全英文的。
环境：
系统：Ubuntu14.04LTS
snmp版本：net-snmp-5.7.3
step1.编写MIB文件
在上一篇文章中，已经注释解释了教为通用的部分，今天这个MIB加入了Table，稍有不同：
QQMIB DEFINITIONS ::= BEGIN
IMPORTS
OBJECT-GROUP, MODULE-COMPLIANCE, NOTIFICATION-GROUP
FROM SNMPv2-CONF
enterprises, Integer32, Unsigned32, OBJECT-TYPE, MODULE-IDENTITY,NOTIFICATION-TYPE
FROM SNMPv2-SMI
DisplayString, RowStatus
FROM SNMPv2-TC;
--.1.3.6.1.4.1.73691
QQMIB OBJECT IDENTIFIER ::= { enterprises 73691 }
--.1.3.6.1.4.1.73691.1
qosTableRoot OBJECT IDENTIFIER ::= { QQMIB 1 }
--创建一个table，必须以xxxTable这样的格式命名
--注意MAX-ACCESS的设置
--.1.3.6.1.4.1.73691.1.1
qosTable OBJECT-TYPE
SYNTAX SEQUENCE OF QosEntry
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"专用承载列表"
::= { qosTableRoot 1 }
--创建Entry对象，理解为Row，格式为xxxEntry，注意和定义的Entry对象名区别开
--注意INDEX一定要的
--.1.3.6.1.4.1.73691.1.1.1
qosEntry OBJECT-TYPE
SYNTAX QosEntry
MAX-ACCESS read-create
STATUS current
DESCRIPTION
""
INDEX { qosIndex }
::= { qosTable 1 }
--定义Entry对象，格式为xxxEntry，注意和创建Entry对象名区别开
--这里定义Index，RowStatus是必须的，其他的就按照需求自定义了
QosEntry::= SEQUENCE {
qosIndex Integer32,
WANDevice Integer32,
DLMaxRate Unsigned32,
qosRowStatus RowStatus
}
--.1.3.6.1.4.1.73691.1.1.1.1
qosIndex OBJECT-TYPE
SYNTAX Integer32
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"index"
::= { qosEntry 1 }
--.1.3.6.1.4.1.73691.1.1.1.2
WANDevice OBJECT-TYPE
SYNTAX Integer32
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"参数解释：广域网侧设备。取值范围：4 - 4 ,默认值：4"
::= { qosEntry 2 }
--.1.3.6.1.4.1.73691.1.1.1.3
DLMaxRate OBJECT-TYPE
SYNTAX Unsigned32
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"参数解释：下行最大速率。取值范围：0 - 262144,默认值：262144"
::= { qosEntry 3 }
--注意SYNTAX类型
--.1.3.6.1.4.1.73691.1.1.1.4
qosRowStatus OBJECT-TYPE
SYNTAX RowStatus
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"rowStatus"
::= { qosEntry 4 }
END 需要注意的地方已经在上面的MIB文件中注释了，可别看漏了哦。毕竟漏一些东西，也可以正常生成c文件，最后运行时候命令效果不对，根本不知道哪里出了问题。
step2.使用mib2c工具生成c文件
和上篇文章一样，不多赘述。输入指令，依据需求选择：
zzj@sed:~/net-snmp/net-snmp-5.7.3/local$ env MIBS="+/home/zzj/.snmp/mibs/QQ-MIB.txt" mib2c qosTableRoot
writing to -
mib2c has multiple configuration files depending on the type of
code you need to write. You must pick one depending on your need.
You requested mib2c to be run on the following part of the MIB tree:
OID: qosTableRoot
numeric translation: .1.3.6.1.4.1.73691.1
number of scalars within: 0
number of tables within: 1
number of notifications within: 0
First, do you want to generate code that is compatible with the
ucd-snmp 4.X line of code, or code for the newer Net-SNMP 5.X code
base (which provides a much greater choice of APIs to pick from):
1) ucd-snmp style code
2) Net-SNMP style code
Select your choice : 2
**********************************************************************
GENERATING CODE FOR TABLES:
**********************************************************************
The Net-SNMP agent API is extremely extensive and, in fact, lets
each programmer write agent code according to the style that works
best for them based on their experience and their preference. We're
going to ask you a serious of questions that will help mib2c
generate code that best suits *your* needs, as the programmer that
will be responsible for taking the code and further refining it. If
you don't like how the results look, you are always welcome to
re-run mib2c and select a different set of options.
There are essentially two tasks involved in processing requests
for OIDs within a MIB table - firstly identifying the relevant row
of the table for a given request, and then returning (or updating)
the appropriate column value within that row. Many MIB tables model
the state of some external system (the kernel, a device, processes,
etc), and the MIB implementation module (the code we're about to
produce a template for) acts as an interface between this underlying
system and the SNMP side. Other tables hold data internally that is
only available within the agent itself, or at least the master copy
of the data is held within the agent.
There are a number of different code templates that can be used to
implement MIB tables, using various approaches to these two tasks.
There are three basic approaches to identifying the relevant row:
1) Pass the request through to the table-specific code, and
identify the requested row there (for both GET and GETNEXT
requests). This is typically the most efficient way to get
up-to-date information, but relies on suitable
(programmer-provided) code within the MIB handler.
Most importantly, you should be an expert to use this choice.
This will produce code based on the table_dataset handler.
2) Have table-specific code to provide information about which
rows exist in the table (by iterating through them in turn),
but utilise standard helper code to select the appropriate
row for a given request. This is particularly suitable for
tables where the data is naturally stored in a "random" order
(or differently to the MIB table index), or where rows are
frequently added to or removed from the table.
However searching for the requested row is not very efficient,
and performance can be slow - particularly for large tables with
many rows.
3) Hold a locally cached copy of the contents of the table (or at
least a cache of which rows are valid), and utilise standard
helper code to select the appropriate row. This is
significantly faster than the iterator-based approach, but
cached data is inevitably slightly "stale" with respect to the
data from the underlying system being managed. This approach,
since it relies on caching of data, is also results in a larger
memory footprint. It is less appropriate for tables where rows
are frequently added or removed externally to the agent (i.e.,
not via SNMP requests).
This approach can also be used where _all_ use of the table is
via SNMP, and there is no external "underlying system". In
this case, the local cache is the canonical version of the
table.
4) Do not generate code for the tables.
Select the option that best fits your requirements: 2
Having identified the appropriate row for a given request, there are
three basic styles of code for returning (or updating) the requested
column value from within this row:
1) A single handler routine, which contains all the code needed to
handle GET and SET requests for each of the column objects.
The code typically looks like a single function with a large 'case'
statement covering each of the columns.
This will produce code based on the 'iterator' hepler.
2) A set of individual routines, each of which is concerned
with a particular aspect of processing the request.
Each column object within the table has one routine for
retrieving the current value, and another for setting a new one.
This will produce code based on the 'iterate_access' hepler.
3) A (different) set of individual routines, each of which is
smaller and more tightly focused than the code generated by
style 2. The aim here is to reduce the amount of SNMP specific
knowledge required to implement a module, and hide much of the
SNMP terminology and processing within standard generated code
(which can simply be used sight unseen).
However this style of code can only be generated when mib2c
is run on an individual MIB table. To use this approach, you
will need to re-invoke mib2c with the name of a single MIB table.
This will produce code based on the 'mfd' hepler ('MIB for Dummies').
4) Do not generate code for the tables.
(In all cases, GETNEXT requests are automatically converted
into the equivalent GET request, so the MIB specific code
need only be concerned with GET and SET requests.).
Select the code style you wish to use: 1
The same template code can be generated using
mib2c -c mib2c.iterate.conf qosTableRoot
This framework can work in one of two ways:
1) Hold a local cached copy of some external data
which is then used to service incoming requests.
2) Query the external data directly for each request.
The first is typically more efficient, but results in
slightly "stale" data (depending on the expiration timeout
for the cache) and greater memory usage. The second can
provide more up-to-date information, but at the cost of
higher processing overheads.
Which is more appropriate for your needs?
Select your choice : 1
writing to qosTableRoot.h
writing to qosTableRoot.c
**********************************************************************
* NOTE WELL: The code generated by mib2c is only a template. *YOU* *
* must fill in the code before it'll work most of the time. In many *
* cases, spots that MUST be edited within the files are marked with *
* /* XXX */ or /* TODO */ comments. *
**********************************************************************
running indent on qosTableRoot.h
running indent on qosTableRoot.c
我的选项如上，供大伙在“感觉不太对”时，找回自信。生成的c代码如下，我在代码中做好了注释：
/*
* Note: this file originally auto-generated by mib2c using
* $
*/
#include <net-snmp/net-snmp-config.h>
#include <net-snmp/net-snmp-includes.h>
#include <net-snmp/agent/net-snmp-agent-includes.h>
#include "qosTableRoot.h"
/** Initializes the qosTableRoot module */
void
init_qosTableRoot(void)
{
/* here we initialize all the tables we're planning on supporting */
initialize_table_qosTable();
}
/*XXX 注释掉*/
# Determine the first/last column names
/** Initialize the qosTable table by defining its contents and how it's structured */
void
initialize_table_qosTable(void)
{
const oid qosTable_oid[] = {1,3,6,1,4,1,73691,1,1};
const size_t qosTable_oid_len = OID_LENGTH(qosTable_oid);
netsnmp_handler_registration *reg;
netsnmp_iterator_info *iinfo;
netsnmp_table_registration_info *table_info;
DEBUGMSGTL(("qosTableRoot:init", "initializing table qosTable\n"));
reg = netsnmp_create_handler_registration(
"qosTable", qosTable_handler,
qosTable_oid, qosTable_oid_len,
HANDLER_CAN_RWRITE
);
table_info = SNMP_MALLOC_TYPEDEF( netsnmp_table_registration_info );
netsnmp_table_helper_add_indexes(table_info,
ASN_INTEGER, /* index: qosIndex */
0);
table_info->min_column = COLUMN_QOSINDEX;
table_info->max_column = COLUMN_QOSROWSTATUS;
iinfo = SNMP_MALLOC_TYPEDEF( netsnmp_iterator_info );
iinfo->get_first_data_point = qosTable_get_first_data_point;
iinfo->get_next_data_point = qosTable_get_next_data_point;
iinfo->table_reginfo = table_info;
netsnmp_register_table_iterator( reg, iinfo );
netsnmp_inject_handler_before( reg,
netsnmp_get_cache_handler(QOSTABLE_TIMEOUT,
qosTable_load, qosTable_free,
qosTable_oid, qosTable_oid_len),
TABLE_ITERATOR_NAME);
/* Initialise the contents of the table here */
/* XXX 便于测试，你可以在这里初始化几行数据*/
}
/* Typical data structure for a row entry */
struct qosTable_entry {
/* Index values */
long qosIndex;
/* Column values */
long qosIndex;
long old_qosIndex;
long WANDevice;
long old_WANDevice;
u_long DLMaxRate;
u_long old_DLMaxRate;
long qosRowStatus;
/* Illustrate using a simple linked list */
int valid;
struct qosTable_entry *next;
};
struct qosTable_entry *qosTable_head;
/* create a new row in the (unsorted) table */
struct qosTable_entry *
qosTable_createEntry(
long qosIndex,
/*XXX 把参数补齐 */
) {
struct qosTable_entry *entry;
entry = SNMP_MALLOC_TYPEDEF(struct qosTable_entry);
if (!entry)
return NULL;
entry->qosIndex = qosIndex;
/*XXX 赋值 */
entry->next = qosTable_head;
qosTable_head = entry;
return entry;
}
/* XXX 这里和下面调用参数匹配不上，修改使其一致即可*/
/* remove a row from the table */
void
qosTable_removeEntry( struct qosTable_entry *entry ) {
struct qosTable_entry *ptr, *prev;
if (!entry)
return; /* Nothing to remove */
for ( ptr = qosTable_head, prev = NULL;
ptr != NULL;
prev = ptr, ptr = ptr->next ) {
if ( ptr == entry )
break;
}
if ( !ptr )
return; /* Can't find it */
if ( prev == NULL )
qosTable_head = ptr->next;
else
prev->next = ptr->next;
SNMP_FREE( entry ); /* XXX - release any other internal resources */
}
/* Example cache handling - set up linked list from a suitable file */
int
qosTable_load( netsnmp_cache *cache, void *vmagic ) {
FILE *fp;
struct qosTable_entry *this;
char buf[STRMAX];
/* The basic load routine template assumes that the data to
be reported is held in a file - with one row of the file
for each row of the table.
If your data is available via a different API, you
should amend this initial block (and the control of the
'while' loop) accordingly.
'XXX' marks where the template is incomplete and
code will definitely need to be added. */
//初始化操作，在这里读取文件，加载到table中
fp = fopen( "/data/for/qosTable", "r" );
if ( !fp ) {
return -1;
}
while ( fgets( buf, STRMAX, fp )) {
this = SNMP_MALLOC_TYPEDEF( struct qosTable_entry );
/* XXX - Unpick 'buf' to extract the individual field values
and then populate the 'this' data structure with them */
this->next = qosTable_head;
qosTable_head = this; /* Iterate helper is fine with unordered lists! */
}
fclose(fp);
return 0; /* OK */
}
void
qosTable_free( netsnmp_cache *cache, void *vmagic ) {
struct qosTable_entry *this, *that;
for ( this = qosTable_head; this; this=that ) {
that = this->next;
SNMP_FREE( this ); /* XXX - release any other internal resources */
}
qosTable_head = NULL;
}
/* Example iterator hook routines - using 'get_next' to do most of the work */
netsnmp_variable_list *
qosTable_get_first_data_point(void **my_loop_context,
void **my_data_context,
netsnmp_variable_list *put_index_data,
netsnmp_iterator_info *mydata)
{
*my_loop_context = qosTable_head;
return qosTable_get_next_data_point(my_loop_context, my_data_context,
put_index_data, mydata );
}
netsnmp_variable_list *
qosTable_get_next_data_point(void **my_loop_context,
void **my_data_context,
netsnmp_variable_list *put_index_data,
netsnmp_iterator_info *mydata)
{
struct qosTable_entry *entry = (struct qosTable_entry *)*my_loop_context;
netsnmp_variable_list *idx = put_index_data;
if ( entry ) {
snmp_set_var_typed_integer( idx, ASN_INTEGER, entry->qosIndex );
idx = idx->next_variable;
*my_data_context = (void *)entry;
*my_loop_context = (void *)entry->next;
return put_index_data;
} else {
return NULL;
}
}
//table_row和ret没有定义，自己定义一下吧
/** handles requests for the qosTable table */
int
qosTable_handler(
netsnmp_mib_handler *handler,
netsnmp_handler_registration *reginfo,
netsnmp_agent_request_info *reqinfo,
netsnmp_request_info *requests) {
netsnmp_request_info *request;
netsnmp_table_request_info *table_info;
struct qosTable_entry *table_entry;
DEBUGMSGTL(("qosTableRoot:handler", "Processing request (%d)\n", reqinfo->mode));
switch (reqinfo->mode) {
/*
* Read-support (also covers GetNext requests)
*/
case MODE_GET:
for (request=requests; request; request=request->next) {
table_entry = (struct qosTable_entry *)
netsnmp_extract_iterator_context(request);
table_info = netsnmp_extract_table_info( request);
switch (table_info->colnum) {
case COLUMN_QOSINDEX:
if ( !table_entry ) {
netsnmp_set_request_error(reqinfo, request,
SNMP_NOSUCHINSTANCE);
continue;
}
snmp_set_var_typed_integer( request->requestvb, ASN_INTEGER,
table_entry->qosIndex);
break;
case COLUMN_WANDEVICE:
if ( !table_entry ) {
netsnmp_set_request_error(reqinfo, request,
SNMP_NOSUCHINSTANCE);
continue;
}
snmp_set_var_typed_integer( request->requestvb, ASN_INTEGER,
table_entry->WANDevice);
break;
case COLUMN_DLMAXRATE:
if ( !table_entry ) {
netsnmp_set_request_error(reqinfo, request,
SNMP_NOSUCHINSTANCE);
continue;
}
snmp_set_var_typed_integer( request->requestvb, ASN_UNSIGNED,
table_entry->DLMaxRate);
break;
case COLUMN_QOSROWSTATUS:
if ( !table_entry ) {
netsnmp_set_request_error(reqinfo, request,
SNMP_NOSUCHINSTANCE);
continue;
}
snmp_set_var_typed_integer( request->requestvb, ASN_INTEGER,
table_entry->qosRowStatus);
break;
default:
netsnmp_set_request_error(reqinfo, request,
SNMP_NOSUCHOBJECT);
break;
}
}
break;
/*
* Write-support
*/
case MODE_SET_RESERVE1:
for (request=requests; request; request=request->next) {
table_entry = (struct qosTable_entry *)
netsnmp_extract_iterator_context(request);
table_info = netsnmp_extract_table_info( request);
switch (table_info->colnum) {
case COLUMN_QOSINDEX:
/* or possibly 'netsnmp_check_vb_int_range' */
ret = netsnmp_check_vb_int( request->requestvb );
if ( ret != SNMP_ERR_NOERROR ) {
netsnmp_set_request_error( reqinfo, request, ret );
return SNMP_ERR_NOERROR;
}
break;
case COLUMN_WANDEVICE:
/* or possibly 'netsnmp_check_vb_int_range' */
ret = netsnmp_check_vb_int( request->requestvb );
if ( ret != SNMP_ERR_NOERROR ) {
netsnmp_set_request_error( reqinfo, request, ret );
return SNMP_ERR_NOERROR;
}
break;
case COLUMN_DLMAXRATE:
/* or possibly 'netsnmp_check_vb_int_range' */
ret = netsnmp_check_vb_int( request->requestvb );
if ( ret != SNMP_ERR_NOERROR ) {
netsnmp_set_request_error( reqinfo, request, ret );
return SNMP_ERR_NOERROR;
}
break;
case COLUMN_QOSROWSTATUS:
ret = netsnmp_check_vb_rowstatus(request->requestvb,
(table_entry ? RS_ACTIVE : RS_NONEXISTENT ));
if ( ret != SNMP_ERR_NOERROR ) {
netsnmp_set_request_error( reqinfo, request, ret );
return SNMP_ERR_NOERROR;
}
break;
default:
netsnmp_set_request_error( reqinfo, request,
SNMP_ERR_NOTWRITABLE );
return SNMP_ERR_NOERROR;
}
}
break;
case MODE_SET_RESERVE2:
for (request=requests; request; request=request->next) {
table_entry = (struct qosTable_entry *)
netsnmp_extract_iterator_context(request);
table_info = netsnmp_extract_table_info( request);
switch (table_info->colnum) {
case COLUMN_QOSROWSTATUS:
switch (*request->requestvb->val.integer) {
//按规范，一般是在RESERVE2这里做内存申请等操作，因此在这里创建了新的table_row
case RS_CREATEANDGO:
case RS_CREATEANDWAIT:
table_row = qosTable_createEntry(
, *table_info->indexes->val.integer
);
if (table_row) {
netsnmp_insert_iterator_context( request, table_row );
} else {
netsnmp_set_request_error( reqinfo, request,
SNMP_ERR_RESOURCEUNAVAILABLE );
return SNMP_ERR_NOERROR;
}
}
}
}
break;
case MODE_SET_FREE:
for (request=requests; request; request=request->next) {
table_entry = (struct qosTable_entry *)
netsnmp_extract_iterator_context(request);
table_info = netsnmp_extract_table_info( request);
switch (table_info->colnum) {
case COLUMN_QOSROWSTATUS:
switch (*request->requestvb->val.integer) {
//valid属性是0，表示移除该行，这里怪怪的？可能因为是和SET_FREE有关吧
case RS_CREATEANDGO:
case RS_CREATEANDWAIT:
if (table_entry && !table_entry->valid) {
qosTable_removeEntry(table_data, table_row );
}
}
}
}
break;
case MODE_SET_ACTION:
for (request=requests; request; request=request->next) {
table_entry = (struct qosTable_entry *)
netsnmp_extract_iterator_context(request);
table_info = netsnmp_extract_table_info( request);
switch (table_info->colnum) {
case COLUMN_QOSINDEX:
table_entry->old_qosIndex = table_entry->qosIndex;
table_entry->qosIndex = *request->requestvb->val.integer;
break;
case COLUMN_WANDEVICE:
table_entry->old_WANDevice = table_entry->WANDevice;
table_entry->WANDevice = *request->requestvb->val.integer;
break;
case COLUMN_DLMAXRATE:
table_entry->old_DLMaxRate = table_entry->DLMaxRate;
table_entry->DLMaxRate = *request->requestvb->val.integer;
break;
}
}
/* Check the internal consistency of an active row */
for (request=requests; request; request=request->next) {
table_entry = (struct qosTable_entry *)
netsnmp_extract_iterator_context(request);
table_info = netsnmp_extract_table_info( request);
switch (table_info->colnum) {
case COLUMN_QOSROWSTATUS:
switch (*request->requestvb->val.integer) {
case RS_ACTIVE:
case RS_CREATEANDGO:
/* XXX 这两种状态对应使 指定的Row生效*/
if (/* XXX 异常判断*/) {
netsnmp_set_request_error( reqinfo, request,
SNMP_ERR_INCONSISTENTVALUE );
return SNMP_ERR_NOERROR;
}
}
}
}
break;
case MODE_SET_UNDO:
for (request=requests; request; request=request->next) {
table_entry = (struct qosTable_entry *)
netsnmp_extract_iterator_context(request);
table_info = netsnmp_extract_table_info( request);
switch (table_info->colnum) {
case COLUMN_QOSINDEX:
table_entry->qosIndex = table_entry->old_qosIndex;
table_entry->old_qosIndex = 0;
break;
case COLUMN_WANDEVICE:
table_entry->WANDevice = table_entry->old_WANDevice;
table_entry->old_WANDevice = 0;
break;
case COLUMN_DLMAXRATE:
table_entry->DLMaxRate = table_entry->old_DLMaxRate;
table_entry->old_DLMaxRate = 0;
break;
case COLUMN_QOSROWSTATUS:
switch (*request->requestvb->val.integer) {
case RS_CREATEANDGO:
case RS_CREATEANDWAIT:
if (table_entry && !table_entry->valid) {
qosTable_removeEntry(table_data, table_row );
}
}
break;
}
}
break;
case MODE_SET_COMMIT:
for (request=requests; request; request=request->next) {
table_entry = (struct qosTable_entry *)
netsnmp_extract_iterator_context(request);
table_info = netsnmp_extract_table_info( request);
switch (table_info->colnum) {
case COLUMN_QOSROWSTATUS:
switch (*request->requestvb->val.integer) {
//这里mib2c生成的已帮我们处理好，CREATEANDGO，valid直接是1，同时还把qosRowStatus设置为ACTIVE
case RS_CREATEANDGO:
table_entry->valid = 1;
/* Fall-through */
case RS_ACTIVE:
table_entry->qosRowStatus = RS_ACTIVE;
break;
//创建但是不ACTIVE
case RS_CREATEANDWAIT:
table_entry->valid = 1;
/* Fall-through */
case RS_NOTINSERVICE:
table_entry->qosRowStatus = RS_NOTINSERVICE;
break;
case RS_DESTROY:
qosTable_removeEntry(table_data, table_row );
}
}
}
break;
}
return SNMP_ERR_NOERROR;
}对于RowStatus的几种状态的解释：
-active（1）:表明状态行是可用的
-notInService（2）:表明行存在但不可用
-notReady （3）:表明存在，但因为缺少必要的信息而不能用
-createAndGo （4）:由管理者设置，表明希望创建一个行并设置该行的状态列对象为active
-createAndWait（5）:由管理者设置，表明希望创建一个行，但不可用，从上面的代码看到，是被设置为了notInService
-destroy（6）:删除行
step3.编译、加载动态库
略
step4.调试
先snmpwalk看看情况：
zzj@sed:~/net-snmp/net-snmp-5.7.3/local$ snmpwalk -v2c -c sedwt localhost .1.3.6.1.4.1
SNMPv2-SMI::enterprises.73691.1.1.1.1.1 = INTEGER: 1
SNMPv2-SMI::enterprises.73691.1.1.1.1.2 = INTEGER: 2
SNMPv2-SMI::enterprises.73691.1.1.1.2.1 = INTEGER: 4
SNMPv2-SMI::enterprises.73691.1.1.1.2.2 = INTEGER: 4
SNMPv2-SMI::enterprises.73691.1.1.1.3.1 = Gauge32: 276432
SNMPv2-SMI::enterprises.73691.1.1.1.3.2 = Gauge32: 276433
SNMPv2-SMI::enterprises.73691.1.1.1.4.1 = INTEGER: 0
SNMPv2-SMI::enterprises.73691.1.1.1.4.2 = INTEGER: 0看来比较正常（本文在初始化中添加了2行数据），下面我们来添加一行数据：添加一行index为5的数据：
zzj@sed:~/net-snmp/net-snmp-5.7.3/local$ snmpset -v2c -c sedwt localhost .1.3.6.1.4.1.73691.1.1.1.4.5 i 5
SNMPv2-SMI::enterprises.73691.1.1.1.4.5 = INTEGER: 5
zzj@sed:~/net-snmp/net-snmp-5.7.3/local$ snmpwalk -v2c -c sedwt localhost .1.3.6.1.4.1
SNMPv2-SMI::enterprises.73691.1.1.1.1.1 = INTEGER: 1
SNMPv2-SMI::enterprises.73691.1.1.1.1.2 = INTEGER: 2
SNMPv2-SMI::enterprises.73691.1.1.1.1.5 = INTEGER: 5
SNMPv2-SMI::enterprises.73691.1.1.1.2.1 = INTEGER: 4
SNMPv2-SMI::enterprises.73691.1.1.1.2.2 = INTEGER: 4
SNMPv2-SMI::enterprises.73691.1.1.1.2.5 = INTEGER: 0
SNMPv2-SMI::enterprises.73691.1.1.1.3.1 = Gauge32: 276432
SNMPv2-SMI::enterprises.73691.1.1.1.3.2 = Gauge32: 276433
SNMPv2-SMI::enterprises.73691.1.1.1.3.5 = Gauge32: 0
SNMPv2-SMI::enterprises.73691.1.1.1.4.1 = INTEGER: 0
SNMPv2-SMI::enterprises.73691.1.1.1.4.2 = INTEGER: 0
SNMPv2-SMI::enterprises.73691.1.1.1.4.5 = INTEGER: 2看到已经添加了一行数据，剩下分别set各属性值，最后设置RowStatus为active(1)就好了。
删除和修改都比较简单，就不贴过程了。