PySNMP hexValue 到 IP

Question

我正在使用 PySNMP 获取 CDP 邻居的 IP。这是我当前的函数，它可以工作，但输出的类型是 hexValue.

def get_neighbors():
    for (errorIndication,
         errorStatus,
         errorIndex,
         values) in nextCmd(SnmpEngine(),
                            CommunityData('public', mpModel=0),
                            UdpTransportTarget((SWITCH, 161)),
                            ContextData(),
                            ObjectType(ObjectIdentity('CISCO-CDP-MIB', 'cdpCacheAddress')).addAsn1MibSource('file://asn1/CISCO-CDP-MIB'),
                            lexicographicMode=False, lookupNames=True, lookupValues=True):
        print(values)
        for v in values:
            print(v)

输出如下：

[ObjectType(ObjectIdentity(ObjectName('1.3.6.1.4.1.9.9.23.1.2.1.1.4.10106.14')), CiscoNetworkAddress(hexValue='ac14103a'))]
CISCO-CDP-MIB::cdpCacheAddress.10106.14 = 0xac14103a
[ObjectType(ObjectIdentity(ObjectName('1.3.6.1.4.1.9.9.23.1.2.1.1.4.10125.9')), CiscoNetworkAddress(hexValue='ac1413fc'))]
CISCO-CDP-MIB::cdpCacheAddress.10125.9 = 0xac1413fc

如何将 0xac14103a 转换为 IP 地址？或者是否有可能以某种方式获取 CiscoNetworkAddress 的值？

Answer 1

根据 CISCO-TC MIB，您必须根据 cacheAddressType 列指定的地址类型手动解释地址值：

CiscoNetworkAddress ::= TEXTUAL-CONVENTION
    DESCRIPTION
        "Represents a network layer address.  The length and format of
        the address is protocol dependent as follows:
        ip        4 octets
        ...
        ipv6      16 octets
        ...
        http     up to 70 octets
SYNTAX          OCTET STRING

如果它是 IPv4 值，您可以手动将该八位字节字符串转换为 IPv4 地址：

# unpacking your `v` loop variable which is a tuple of SNMP var-bindings
# both `oid` and `value` are pysnmp objects representing SNMP types...
>>> oid, value = v
>>> '.'.join([str(x) for x in value.asNumbers()])
'172.20.16.58'

或使用 ipaddress stdlib 模块：

>>> ipaddress.IPv4Address(value.asOctets())
IPv4Address('172.20.16.58')

PySNMP hexValue 到 IP

PySNMP hexValue to IP

python-3.x

pysnmp