SNMP Management:Management Information Base

by

Behzad Akbari

Fall 2008

In the Name of the Most High

MIBUsed to group related objects together

Facilitates logical assignment of object identifiers

That will be the way the objects are stored and accessed

Not to be mistaken with aggregate object type

MIB-II (RFC 1213) is superset of MIB-I

Objects that are related grouped into object groups

MIB module comprises module name, imports from other modules, and definitions of current module

RFC 1213 defines eleven groups

MIB II (RFC 1213) System Group

Provide general information about the managed system. Interfaces Group

Contains generic information about the physical interfaces. Address-Translation Group

Contains information about the mapping between network addresses and physical addresses for each physical interface.

IP Group Contains information about the implementation and operation

of IP at the managed system. ICMP Group

Contains information about the implementation and operation of ICMP at the managed system.

MIB-II (cont.) TCP Group

Contains information about the implementation and operation of TCP at the managed system.

UDP Group Contains information about the implementation and operation of UDP

at the managed system. EGP Group

Contains information about the implementation and operation of EGP at the managed system.

CMOT Group Placeholder for OSI (CMIP Over TCP/IP)

Transmission Group Provides details about the underlying transmission media for each

interface. SNMP Group

Provides the statistics of SNMP operations at the managed system.

MIB-2 OBJECT IDENTIFIER{mgmt 1}

System Group

System Group

sysServices OBJECT-TYPE SYNTAX INTEGER (0..127) ACCESS read-only STATUS mandatory DESCRIPTION "A value which indicates the set of services that this entity primarily offers. The value is a sum. This sum initially takes the value zero, Then, for each layer, L, in the range 1 through 7, that this node performs transactions for, 2 raised to (L - 1) is added to the sum. For example, a node which performs primarily routing functions would have a value of 4 (2^(3-1)). In contrast, a node which is a host offering application services would have a value of 72 (2^(4-1) + 2^(7-1)). Note that in the context of the Internet suite of protocols, values should be calculated accordingly: layer functionality 1 physical (e.g., repeaters) 2 datalink/subnetwork (e.g., bridges) 3 internet (e.g., IP gateways) 4 end-to-end (e.g., IP hosts) 7 applications (e.g., mail relays) For systems including OSI protocols, layers 5 and 6 may also be counted." ::= { system 7 }

72= 8 + 64

01000100

Interfaces GroupInterfaces Group

iFEntry

ifEntry OBJECT-TYPE SYNTAX IfEntry ACCESS not-accessible STATUS mandatory DESCRIPTION

"An interface entry containing objects at the subnetwork layer and below for a particular interface."

INDEX {ifIndex}

::= {ifTable 1}

ifType

http://www.iana.org/assignments/smi-numbers

ifType OBJECT-TYPE SYNTAX INTEGER { other(1), -- none of the following regular1822(2), hdh1822(3), ddn-x25(4), rfc877-x25(5), ethernet-csmacd(6), iso88023-csmacd(7), iso88024-tokenBus(8), iso88025-tokenRing(9), iso88026-man(10), starLan(11), proteon-10Mbit(12), proteon-80Mbit(13), hyperchannel(14), fddi(15), lapb(16), sdlc(17), ds1(18), -- T-1 e1(19), -- european equiv. of T-1 basicISDN(20), primaryISDN(21), -- proprietary serial propPointToPointSerial(22), ppp(23),

……….

ifAdminStatus OBJECT-TYPE SYNTAX INTEGER { up(1), -- ready to pass packets down(2), testing(3) -- in some test mode } ACCESS read-write STATUS mandatory DESCRIPTION "The desired state of the interface. The testing(3) state indicates that no operational packets can be passed." ::= { ifEntry 7 }

ifOperStatus OBJECT-TYPE SYNTAX INTEGER { up(1), -- ready to pass packets down(2), testing(3) -- in some test mode } ACCESS read-only STATUS mandatory DESCRIPTION "The current operational state of the interface. The testing(3) state indicates that no operational packets can be passed." ::= { ifEntry 8 }

ifTable

ifTable (cont.)

IP GroupIP Group

IP Group

• ipForwarding: • forwarding(1)• not-forwarding(2)

• IP Address Table contains table of IP addresses• IP Route Table contains an entry for each route• IP Network-to-Media Table is address translation

table mapping IP addresses to physical addresses

IP Address Table

ipAddrTable

IP Routing Table

IP Routing TableEntity OID Description (brief)

ipRouteTable ip 21 IP routing tableipRouteEntry ipRouteTable 1 Route to a particular destinationipRouteDest ipRouteEntry 1 Destination IP address of this routeipRouteIfIndex ipRouteEntry 2 Index of interface, same as ifIndexipRouteMetric1 ipRouteEntry 3 Primary routing metric for this routeipRouteMetric2 ipRouteEntry 4 An alternative routing metric for this routeipRouteMetric3 ipRouteEntry 5 An alternative routing metric for this routeipRouteMetric4 ipRouteEntry 6 An alternative routing metric for this routeipRouteNextHop ipRouteEntry 7 IP address of the next hopipRouteType ipRouteEntry 8 Type of routeipRouteProto ipRouteEntry 9 Routing mechanism by which this route was

learnedipRouteAge ipRouteEntry 10 Number of seconds since routing was last updatedipRouteMask ipRouteEntry 11 Mask to be logically ANDed with the destination

address before comparing with the ipRouteDestfield

ipRouteMetric5 ipRouteEntry 12 An alternative metric for this routeipRouteInfo ipRouteEntry 13 Reference to MIB definition specific to the routing

protocol

ipRouteTable Example

other(1), invalid(2), direct(3), indirect(4)

other(1), local(2), netmgmt(3),icmp(4), egp(5),ggp(6),hello(7),rip(8),is-is(9),s-is(10),ciscoIgrp(11),bbnSpfIgp(12),ospf(13),bgp(14)

Sec.

IP Address Translation Table

IP Address Translation Table

Entity OID Description (brief)ipNetToMediaTable ip 22 Table mapping IP addresses to

physical addressesipNetToMediaEntry IpNetToMediaTable 1 IP address to physical address

for the particular interfaceipNetToMediaIfIndex IpNetToMediaEntry 1 Interfaces on which this entry's

equivalence is effective; sameas ifIndex

ipNetToMediaPhysAddress IpNetToMediaEntry 2 Media dependent physicaladdress

ipNetToMediaNetAddress IpNetToMediaEntry 3 IP addressipNetToMediaType IpNetToMediaEntry 4 Type of mapping

IPNetToMediaTable

= ARP Table

other(1),invalid(2)invalid(2), dynamic(3),static(4)

read-write

ICMP Group

ICMP

• Objects associated with ping• icmpOutEchos

- # ICMP echo messages sent• icmpInEchoReps

- # ICMP echo reply messages received

• Objects associated with traceroute/tracert• icmpInTimeExcs

• # ICMP time exceeded messages received

TCP Group

TCP Connection Table

TCP Connection Table

Entity OID Description (brief)

tcpConnTable tcp 13 TCO connection tabletcpconnEntry TcpConnTable 1 Information about a particular TCP

connectiontcpConnState TcpConnEntry 1 State of the TCP connectiontcpConnLocalAddressTcpConnEntry 2 Local IP addresstcpConnLocalPort TcpConnEntry 3 Local port numbertcpConnRemAddress TcpConnEntry 4 Remote IP addresstcpConnRemPort TcpConnEntry 5 Remote port number

tcpConnState OBJECT-TYPE SYNTAX INTEGER { closed(1), listen(2), synSent(3), synReceived(4), established(5), finWait1(6), finWait2(7), closeWait(8), lastAck(9), closing(10), timeWait(11), deleteTCB(12)deleteTCB(12) } ACCESS read-write STATUS mandatory …::= { tcpConnEntry 1 }

TCP Connection StateTCP Connection State

tcpConnTable

UDP Group

UDP Group

Entity OID Description (brief)udpInDatagrams udp 1 Total number of datagrams delivered to the

usersudpNoPorts udp 2 Total number of received datagrams for

which there is no applicationudpInErrors udp 3 Number of received datagrams with errorsudpOutDatagrams udp 4 Total number of datagrams sentudpTable udp 5 UDP Listener tableudpEntry udpTable 1 Information about a particular connection or

UDP listenerudpLocalAddress udpEntry 1 Local IP addressudpLocalPort udpEntry 2 Local UDP port

udpTable