CISCO-DHCP-RELAY-MIB

All MIBs › CISCO-DHCP-RELAY-MIB

Organization: Cisco Systems, Inc.

Last Updated: 2016-09-16

Category: Cisco Devices, IP and Core Protocols

Description: Manages DHCP relay agent configuration and statistics on Cisco devices, tracking relayed discover/offer/request/ack message counts.

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What Is CISCO-DHCP-RELAY-MIB?

CISCO-DHCP-RELAY-MIB is a Cisco proprietary MIB for the DHCP relay agent feature, tracking statistics on DHCP messages (discover, offer, request, ack) relayed between clients and a centralized DHCP server. It exposes performance and fault counters: packets received, forwarded and dropped per interface and per message type, plus a breakdown of drop reasons. It is a software-service monitoring MIB rather than a hardware one, useful for detecting a misconfigured relay (via the relay-not-enabled drop counter) or unusual traffic patterns such as a DHCP flood revealed by rising invalid-message-type drops. It complements standard interface instrumentation, since its statistics tables are indexed by ifIndex from IF-MIB. It is deployed on Cisco routers and Layer 3 switches acting as DHCP relay agents between end-user segments and centralized DHCP infrastructure. Engineers can download the CISCO-DHCP-RELAY-MIB file directly to load it into their MIB browser.

IPNetwork Monitor allows you to monitor SNMP objects defined in CISCO-DHCP-RELAY-MIB. Use the built-in SNMP Monitoring Browser to explore available variables, view their current values and descriptions, and select the objects you want to monitor. You can then create SNMP monitors, configure thresholds, and receive alerts when monitored values change.

Supported Devices

Cisco routers and Layer 3 switches acting as DHCP relay agents

Monitoring Examples

cdrStatsTable/cdrStatsEntry, indexed by cdrStatsIfIndex and cdrStatsPktType, tracks cdrStatsPktsReceived versus cdrStatsPktsForwarded and cdrStatsPktsDropped per interface, letting an admin spot an interface silently dropping DHCP requests. cdrDropStatsTable's cdrDropStatsRelayNotEnabled and cdrDropStatsInvalidMsgType break down why packets were dropped, distinguishing a misconfigured relay from malformed or attack traffic.

What Can Be Monitored

DHCP packets received/forwarded/dropped per interface
packet type breakdown (discover/offer/request/ack)
drop reason (relay disabled, invalid message type)
per-interface relay statistics

Imported Objects

From CISCO-SMI

ciscoMgmt

OBJECT-IDENTITY

From CISCO-TC

InterfaceIndexOrZero

From SNMPv2-CONF

MODULE-COMPLIANCE
OBJECT-GROUP

From SNMPv2-SMI

Counter32
MODULE-IDENTITY
OBJECT-TYPE

How to Use in IPNetwork Monitor

Example using cdrStatsPktsReceived OID:

Select a Cisco router or Layer 3 switch (DHCP relay agent) as the target host to create a monitor — the SNMP service should be up and running on it. Click New Monitor, then check SNMP Custom on the Favorites tab, click Next, and confirm the host. On the next page, click Select... to open the built-in SNMP MIB Browser and type cdrStatsPktsReceived into the Find box to locate it in the OID tree, selecting the specific row/instance you want to monitor since this is a table column, then select it and click OK. The number of packets received by the DHCP RELAY agent. On the monitor's Main parameters page you can set the target's SNMP port (default 161), credentials, polling interval, and other settings — see the SNMP Monitor help for details. On the State conditions and Alerting tabs, configure when the monitor should change state and trigger an alert; since this is a Counter32-type OID, Value bounds is the most useful condition here — trigger an alert if the counter increases sharply between polls relative to its normal baseline, since an unexpected spike often reflects a real change in traffic or activity. Click Finish to create the monitor; you can adjust any parameter later.

OIDs

OID symbolic	OID numeric	Type	Access	Description
ciscoDhcpRelayMIB	1.3.6.1.4.1.9.9.833			description
ciscoDhcpRelayMIBNotifs	1.3.6.1.4.1.9.9.833.0
ciscoDhcpRelayMIBObjects	1.3.6.1.4.1.9.9.833.1
ciscoDhcpRelayStats	1.3.6.1.4.1.9.9.833.1.1
cdrStatsTable	1.3.6.1.4.1.9.9.833.1.1.1		not-accessible	This table holds the statistics of the DHCP RELAY operations performed by the RELAY agent running on the device.
cdrStatsEntry	1.3.6.1.4.1.9.9.833.1.1.1.1		not-accessible	An entry holds the statistics of the DHCP RELAY operations performed by the RELAY agent, based on the interface index and the type of the DHCP packet. A zero value of the interface index fetches the total statistics from all the interfaces.
NUM cdrStatsIfIndex	1.3.6.1.4.1.9.9.833.1.1.1.1.1	InterfaceIndexOrZero	not-accessible	The inteface index of the interface on which the RELAY configurations exist. A zero index value refers to the global RELAY statistics.
INT cdrStatsPktType	1.3.6.1.4.1.9.9.833.1.1.1.1.2	INTEGER	not-accessible	The type of the DHCP protocol packet based on which the statistics are fetched upon.
C32 cdrStatsPktsReceivedEx	1.3.6.1.4.1.9.9.833.1.1.1.1.3	Counter32	read-only	The number of packets received by the DHCP RELAY agent.
C32 cdrStatsPktsForwarded	1.3.6.1.4.1.9.9.833.1.1.1.1.4	Counter32	read-only	The number of packets forwarded by the DHCP RELAY agent.
C32 cdrStatsPktsDropped	1.3.6.1.4.1.9.9.833.1.1.1.1.5	Counter32	read-only	The number of packets dropped by the DHCP RELAY agent.
cdrDropStatsTable	1.3.6.1.4.1.9.9.833.1.1.2		not-accessible	This table holds the statistics of the DHCP RELAY packets dropped at an interface/globally in the device.
cdrDropStatsEntry	1.3.6.1.4.1.9.9.833.1.1.2.1		not-accessible	An entry (conceptual row) in the cdrDropStatsTable.
NUM cdrDropStatsIfIndex	1.3.6.1.4.1.9.9.833.1.1.2.1.1	InterfaceIndexOrZero	not-accessible	The statistcs are fetched based upon this index. A zero index value refers to the global RELAY statistics.
C32 cdrDropStatsRelayNotEnabled	1.3.6.1.4.1.9.9.833.1.1.2.1.2	Counter32	read-only	The number of DHCP packets dropped by the RELAY agent as the relay feature was not enabled
C32 cdrDropStatsInvalidMsgType	1.3.6.1.4.1.9.9.833.1.1.2.1.3	Counter32	read-only	The number of DHCP packets dropped by the RELAY agent as the DHCP message type was invalid
C32 cdrDropStatsInterfaceError	1.3.6.1.4.1.9.9.833.1.1.2.1.4	Counter32	read-only	The number of DHCP packets dropped by the RELAY agent, as there was an interface related error.
C32 cdrDropStatsTxFailureServer	1.3.6.1.4.1.9.9.833.1.1.2.1.5	Counter32	read-only	The number of DHCP packets dropped by the RELAY agent as there was a transmission failure towards the Server.
C32 cdrDropStatsTxFailureClient	1.3.6.1.4.1.9.9.833.1.1.2.1.6	Counter32	read-only	The number of DHCP packets dropped by the RELAY agent as there was a transmission failure towards the Client.
C32 cdrDropStatsUnknownOpInterface	1.3.6.1.4.1.9.9.833.1.1.2.1.7	Counter32	read-only	The number of DHCP packets dropped by the RELAY agent as the output Interface was unknown.
C32 cdrDropStatsUnknownVrfOrInterface	1.3.6.1.4.1.9.9.833.1.1.2.1.8	Counter32	read-only	The number of DHCP packets dropped by the RELAY agent as the VRF or Interface towards the Server was unknown.
C32 cdrDropStatsMaxHopsExceeded	1.3.6.1.4.1.9.9.833.1.1.2.1.9	Counter32	read-only	The number of DHCP packets dropped by the RELAY agent, as the maximum number of hops were exceeded.
C32 cdrDropStatsOpt82ValidationFailure	1.3.6.1.4.1.9.9.833.1.1.2.1.10	Counter32	read-only	The number of DHCP packets dropped by the RELAY agent, as the Option 82 validation was failed.
C32 cdrDropStatsMalformedPkts	1.3.6.1.4.1.9.9.833.1.1.2.1.11	Counter32	read-only	The number of DHCP packets dropped by the RELAY agent, as the packets were malformed.
C32 cdrDropStatsUntrustablePort	1.3.6.1.4.1.9.9.833.1.1.2.1.12	Counter32	read-only	The number of DHCP packets dropped by the RELAY agent, as the trusted port is not configured.
C32 cdrDropStatsReqDroppedOnMCT	1.3.6.1.4.1.9.9.833.1.1.2.1.13	Counter32	read-only	The number of DHCP packets dropped by the RELAY agent as the DHCP Request was dropped on MCT.
cdrIPv6StatsTable	1.3.6.1.4.1.9.9.833.1.1.3		not-accessible	This table holds the statistics of the IPv6 DHCP RELAY operations performed by the RELAY agent running on the device.
cdrIPv6StatsEntry	1.3.6.1.4.1.9.9.833.1.1.3.1		not-accessible	An entry holds the statistics of the IPv6 DHCP RELAY operations performed by the RELAY agent, based on the interface index and the type of the DHCP packet. A zero value of the interface index fetches the total statistics from all the interfaces.
NUM cdrIPv6StatsIfIndex	1.3.6.1.4.1.9.9.833.1.1.3.1.1	InterfaceIndexOrZero	not-accessible	The inteface index of the interface on which the RELAY configurations exist. A zero index value refers to the global RELAY statistics.
INT cdrIPv6StatsPktType	1.3.6.1.4.1.9.9.833.1.1.3.1.2	INTEGER	not-accessible	The type of the IPv6 DHCP protocol packet based on which the statistics are fetched upon.
C32 cdrIPv6StatsPktsReceived	1.3.6.1.4.1.9.9.833.1.1.3.1.3	Counter32	read-only	The number of packets received by the IPv6 DHCP RELAY agent.
C32 cdrIPv6StatsPktsForwarded	1.3.6.1.4.1.9.9.833.1.1.3.1.4	Counter32	read-only	The number of packets forwarded by the IPv6 DHCP RELAY agent.
C32 cdrIPv6StatsPktsDropped	1.3.6.1.4.1.9.9.833.1.1.3.1.5	Counter32	read-only	The number of packets dropped by the IPv6 DHCP RELAY agent.
cdrIPv6DropStatsTable	1.3.6.1.4.1.9.9.833.1.1.4		not-accessible	This table holds the statistics of the IPv6 DHCP RELAY packets dropped at an interface/globally in the device.
cdrIPv6DropStatsEntry	1.3.6.1.4.1.9.9.833.1.1.4.1		not-accessible	An entry (conceptual row) in the cdrIPv6DropStatsTable.
NUM cdrIPv6DropStatsIfIndex	1.3.6.1.4.1.9.9.833.1.1.4.1.1	InterfaceIndexOrZero	not-accessible	The statistcs are fetched based upon this index. A zero index value refers to the global RELAY statistics.
C32 cdrIPv6DropStatsRelayDisabled	1.3.6.1.4.1.9.9.833.1.1.4.1.2	Counter32	read-only	The number of DHCP packets dropped by the IPv6 RELAY agent as the relay feature was not enabled
C32 cdrIPv6DropStatsMaxHopsExceeded	1.3.6.1.4.1.9.9.833.1.1.4.1.3	Counter32	read-only	The number of DHCP packets dropped by the IPv6 RELAY agent, as the maximum number of hops were exceeded.
C32 cdrIPv6DropStatsInvalidPkts	1.3.6.1.4.1.9.9.833.1.1.4.1.4	Counter32	read-only	The number of DHCP packets dropped by the IPv6 RELAY agent as the DHCP packet was invalid
C32 cdrIPv6DropStatsUnknownOpInterface	1.3.6.1.4.1.9.9.833.1.1.4.1.5	Counter32	read-only	The number of DHCP packets dropped by the IPv6 RELAY agent as the output Interface was unknown.
C32 cdrIPv6DropStatsInvalidVRF	1.3.6.1.4.1.9.9.833.1.1.4.1.6	Counter32	read-only	The number of DHCP packets dropped by the IPv6 RELAY agent as the VRF was invalid.
C32 cdrIPv6DropStatsOptionInsertionFailed	1.3.6.1.4.1.9.9.833.1.1.4.1.7	Counter32	read-only	The number of DHCP packets dropped by the IPv6 RELAY agent, as the option-insertion was failed.
C32 cdrIPv6DropStatsDirectReplyFromServer	1.3.6.1.4.1.9.9.833.1.1.4.1.8	Counter32	read-only	The number of DHCP packets dropped by the IPv6 RELAY agent due to the direct reply from server (Reconfig/Advertise/Reply).
C32 cdrIPv6DropStatsIPv6AddrNotConfigured	1.3.6.1.4.1.9.9.833.1.1.4.1.9	Counter32	read-only	The number of DHCP packets dropped by the IPv6 RELAY agent as the ipv6 address was not configured.
C32 cdrIPv6DropStatsInterfaceError	1.3.6.1.4.1.9.9.833.1.1.4.1.10	Counter32	read-only	The number of DHCP packets dropped by the IPv6 RELAY agent, as there was an interface related error.
C32 cdrIPv6DropStatsVpnOptionDisabled	1.3.6.1.4.1.9.9.833.1.1.4.1.11	Counter32	read-only	The number of DHCP packets dropped by the IPv6 RELAY agent, as the VPN option was disabled.
C32 cdrIPv6DropStatsIpv6ExtnHeaderPresent	1.3.6.1.4.1.9.9.833.1.1.4.1.12	Counter32	read-only	The number of DHCP packets dropped by the IPv6 RELAY agent, as the Ipv6 extension header was present.
C32 cdrIPv6DropStatsReqDroppedOnMCT	1.3.6.1.4.1.9.9.833.1.1.4.1.13	Counter32	read-only	The number of DHCP packets dropped by the IPv6 RELAY agent as the DHCP Request was dropped on MCT.
ciscoDhcpRelayMIBConform	1.3.6.1.4.1.9.9.833.2
ciscoDhcpRelayMIBCompliances	1.3.6.1.4.1.9.9.833.2.1
ciscoDhcpRelayMIBCompliance	1.3.6.1.4.1.9.9.833.2.1.1			This is a default module-compliance containing default object groups.
ciscoDhcpRelayMIBGroups	1.3.6.1.4.1.9.9.833.2.2
cdrStatsGroup	1.3.6.1.4.1.9.9.833.2.2.1			A collection of objects providing the DHCP RELAY related packets statistics.
cdrDropStatsGroup	1.3.6.1.4.1.9.9.833.2.2.2			A collection of objects providing the statistics of the DHCP RELAY packets dropped by the DHCP relay agent.
cdrIPv6StatsGroup	1.3.6.1.4.1.9.9.833.2.2.3			A collection of objects providing the DHCP IPv6 RELAY related packets statistics.
cdrIPv6DropStatsGroup	1.3.6.1.4.1.9.9.833.2.2.4			A collection of objects providing the statistics of the DHCP RELAY packets dropped by the IPv6 DHCP relay agent.

RFC description

Cisco DHCP relay agent management MIB for monitoring DHCP packet forwarding and statistics in IPv4 and IPv6 networks.

Start monitoring Cisco routers and Layer 3 switches (DHCP relay agent) with a free 30-day trial of IPNetwork Monitor. Import MIBs, browse SNMP OIDs, create custom SNMP monitors, configure alerts, and monitor any SNMP-enabled network device from a single console.

Download CISCO-DHCP-RELAY-MIB