我需要从不在我的网络上的远程路由器获取 IP 路由表，从http://www.sharontools.com/online-lab/device/?q=cisco-r2我已启用 snmp 并在路由器上创建 snmp 用户获取此路由表，现在我需要使用 OID 向此路由器发送 snmpget 请求IP 路由表，但是当我从该路由器上的接口列表中向地址（IP）发送请求时，我收到超时错误？我哪里错了，正确的方法是什么？

编辑 1：现在我可以向路由器发出 snmp 请求，但是当我对 ipRouteTable 对象执行 snmpwalk 时，出现以下错误

IP-MIB::ip.21 = No Such Object available on this agent at this OID

用户属于具有对 iso 具有写访问权限的视图的组。

编辑2：从命令输出中添加snmp相关配置show running-config，用户属于组GROUP2：：

snmp-server group GROUP1 v3 priv read ALL-ACCESS 
snmp-server group GROUP2 v3 priv write ROUTE-TABLE 
snmp-server group NetOps v3 priv 
snmp-server view ALL-ACCESS iso included
snmp-server view ALL-ACCESS internet included
snmp-server view ALL-ACCESS ip.21 included
snmp-server view ROUTE-TABLE ip.21 included
snmp-server community public RO
snmp-server community private RW
snmp-server enable traps snmp authentication linkdown linkup coldstart warmstart
snmp-server enable traps flowmon
snmp-server enable traps transceiver all
snmp-server enable traps call-home message-send-fail server-fail
snmp-server enable traps tty
snmp-server enable traps rf
snmp-server enable traps memory
snmp-server enable traps cpu_threshold
snmp-server enable traps eigrp
snmp-server enable traps ospf state-change
snmp-server enable traps ospf errors
snmp-server enable traps ospf retransmit
snmp-server enable traps ospf lsa
snmp-server enable traps ospf cisco-specific state-change nssa-trans-change
snmp-server enable traps ospf cisco-specific state-change shamlink interface
snmp-server enable traps ospf cisco-specific state-change shamlink neighbor
snmp-server enable traps ospf cisco-specific errors
snmp-server enable traps ospf cisco-specific retransmit    
snmp-server enable traps ospf cisco-specific lsa
snmp-server enable traps flex-links status
snmp-server enable traps fru-ctrl
snmp-server enable traps entity
snmp-server enable traps ethernet cfm cc mep-up mep-down cross-connect loop config
snmp-server enable traps ethernet cfm crosscheck mep-missing mep-unknown service-up
snmp-server enable traps ether-oam
snmp-server enable traps aaa_server
snmp-server enable traps flash insertion removal
snmp-server enable traps l2tc threshold sys-threshold
snmp-server enable traps power-ethernet police
snmp-server enable traps rep
snmp-server enable traps vswitch dual-active vsl
snmp-server enable traps udld link-fail-rpt status-change
snmp-server enable traps vtp
snmp-server enable traps vlancreate
snmp-server enable traps vlandelete
snmp-server enable traps auth-framework sec-violation
snmp-server enable traps dot1x auth-fail-vlan guest-vlan no-auth-fail-vlan no-guest-vlan
snmp-server enable traps envmon fan shutdown supply temperature status
snmp-server enable traps entity-diag boot-up-fail hm-test-recover hm-thresh-reached scheduled-test-fail
snmp-server enable traps port-security
snmp-server enable traps ethernet evc status create delete
snmp-server enable traps energywise        
snmp-server enable traps ipsla
snmp-server enable traps vstack
snmp-server enable traps bfd
snmp-server enable traps bgp
snmp-server enable traps bulkstat collection transfer
snmp-server enable traps cef resource-failure peer-state-change peer-fib-state-change inconsistency
snmp-server enable traps config-copy
snmp-server enable traps config
snmp-server enable traps config-ctid
snmp-server enable traps event-manager
snmp-server enable traps hsrp
snmp-server enable traps ipmulticast
snmp-server enable traps isis
snmp-server enable traps msdp
snmp-server enable traps pim neighbor-change rp-mapping-change invalid-pim-message
snmp-server enable traps bridge newroot topologychange
snmp-server enable traps stpx inconsistency root-inconsistency loop-inconsistency    
snmp-server enable traps syslog
snmp-server enable traps isakmp policy add
snmp-server enable traps isakmp policy delete
snmp-server enable traps isakmp tunnel start
snmp-server enable traps isakmp tunnel stop
snmp-server enable traps ipsec cryptomap add
snmp-server enable traps ipsec cryptomap delete
snmp-server enable traps ipsec cryptomap attach
snmp-server enable traps ipsec cryptomap detach
snmp-server enable traps ipsec tunnel start
snmp-server enable traps ipsec tunnel stop
snmp-server enable traps ipsec too-many-sas
snmp-server enable traps errdisable
snmp-server enable traps ethernet cfm alarm
snmp-server enable traps vlan-membership
snmp-server enable traps mac-notification change move threshold
snmp-server enable traps vrfmib vrf-up vrf-down vnet-trunk-up vnet-trunk-down