System Management Guide: Communications and Networks

SNMP Daemon Support for the EGP Family of MIB Variables

If the agent host is running the gated daemon with the Exterior Gateway Protocol (EGP) enabled, there are several Management Information Base (MIB) variables in the EGP group supported by the gated daemon which the snmpd agent can access.

The following EGP MIB variables have a single, unique instance:

The following EGP MIB variables have an instance for each EGP peer or neighbor acquired by the agent host gated daemon:

If the gated daemon is not running, or if the gated daemon is running but is not configured to communicate with the snmpd agent, or if the gated daemon is not configured for EGP, get and set requests for the values of these variables will return the noSuchName error response code.

The gated daemon configuration file, /etc/gated.conf, should contain the following statement:

snmp      yes;

The gated daemon is internally configured to be an Simple Network Management Protocol (SNMP) single multiplexer (SMUX) protocol peer, or proxy agent, of the snmpd daemon. When the gated daemon starts up, it registers the ipRouteTable MIB variable tree with the snmpd agent. If the gated daemon is configured for EGP, then the gated daemon also registers the EGP MIB variable tree. After this registration is complete, an SNMP manager can successfully make requests to the snmpd agent for the ipRouteTable an EGP MIB variables supported by this agent host gated daemon. When the gated daemon is running, all MIB routing information is obtained using the gated daemon. In this case, set requests to the ipRouteTable are not allowed.

The SMUX communication between the gated daemon and the snmpd daemon takes place over the well-known Transmission Control Protocol (TCP) port 199. If the gated daemon terminates, snmpd immediately unregisters the trees the gated daemon previously registered. If the gated daemon is started before the snmpd daemon, the gated daemon periodically checks for the snmpd daemon until the SMUX association can be established.

To configure the snmpd agent to recognize and allow the SMUX association with the gated daemon client, the user must add a SMUX entry to the /etc/snmpd.conf file. The client object identifier and password specified in this SMUX entry for the gated daemon must match those specified in the /etc/snmpd.peers file.

The snmpd agent supports set requests for the following read-write MIB I and MIB II variables:

sysContact

The textual identification of the contact person for this agent host. This information includes the name of this person and how to contact this person: for example, "Bob Smith, 555-5555, ext 5." The value is limited to 256 characters. If, for a set request, the string for this MIB variable is greater than 256 characters, the snmpd agent will return the error badValue, and the set operation is not performed. The initial value of sysContact is defined in /etc.snmp.conf. If nothing is defined, the value is null string.

Instance	Value	Action
0	"string"	The MIB variable is set to "string".

sysName

The host name for this agent host. Typically this is the fully qualified domain name of the node. The value is limited to 256 characters. If, for a set request, the string for this MIB variable is greater than 256 characters, the snmpd agent returns the error badValue, and the set operation is not performed.

Instance	Value	Action
0	"string"	The MIB variable is set to "string".

sysLocation

A textual string stating the physical location of the machine on which this snmpd agent resides: for example, "Austin site, building 802, lab 3C-23." The value is limited to 256 characters. If, for a set request, the string for this MIB variable is greater than 256 characters, the snmpd agent returns the error badValue, and the set operation is not performed. The initial value of sysLocation is defined in /etc/snmp.conf. If nothing is defined, the value is null string.

Instance	Value	Action
0	"string"	The MIB variable is set to "string".

ifAdminStatus

The desired state of an interface adapter on the agent's host. Supported states are up and down. The state can be set to testing but such an action has no effect on the operational state of the interface.

Instance	Value	Action
f	1	The interface adapter with ifIndex f is enabled.

Note: It is possible that the ifAdminStatus value can be set to up or down, yet the actual operational change of the interface failed. In such a case, a get request of the ifAdminStatus might reflect up while an ifOperStatus for that interface might reflect down. If such a situation occurs, the network administrator would issue another set request to set ifAdminStatus to up to attempt the operational change again.

atPhysAddress

The hardware address portion of an address table binding on the agent host (an entry in the Address Resolution Protocol table). This is the same MIB variable as ipNetToMediaPhysAddress.

Instance	Value	Action
f.1.n.n.n.n	hh:hh:hh:hh:hh:hh	For the interface with ifIndex f, any existing ARP table binding for IP address n.n.n.n is replaced with the binding (n.n.n.n, hh:hh:hh:hh:hh:hh). If a binding did not exist, the new binding is added. hh:hh:hh:hh:hh:hh is a twelve-hexadecimal-digit hardware address.

atN0etAddress

The IP address corresponding to the hardware or physical address specified in atPhysAddress. This is the same MIB variable as ipNetToMediaNetAddress.

Instance	Value	Action
f.1.n.n.n.n	m.m.m.m	For the interface with ifIndex f, an existing ARP table entry for IP address n.n.n.n is replaced with IP address m.m.m.m.

ipForwarding

Indicates whether this agent host is forwarding datagrams. See SNMP Daemon Implementation Restrictions for more information on this MIB variable.

Instance	Value	Action
0	1	If the agent host has more than one active interface, then the TCP/IP kernel is configured to forward packets. If the agent host has only one active interface, the set request fails.
	2	The TCP/IP kernel on the agent host is configured to not forward packets.

ipDefaultTTL

The default time-to-live (TTL) value inserted into IP headers of datagrams originated by the agent host.

Instance	Value	Action
0	n	The default time-to-live value used by IP protocol support is set to the integer n.

ipRouteDest

The destination IP address of a route in the route table.

Instance	Value	Action
n.n.n.n	m.m.m.m	The destination route for route n.n.n.n is set to the IP address m.m.m.m.

ipRouteNextHop

The gateway by which a destination IP address can be reached from the agent host (an entry in the route table).

Instance	Value	Action
n.n.n.n	m.m.m.m	A route table entry to reach network n.n.n.n using gateway m.m.m.m is added to the route table. The host portion of the IP address n.n.n.n must be 0 to indicate a network address.

ipRouteType

The state of a route table entry on the agent host (used to delete entries).

Instance	Value	Action
h.h.h.h	1	Any route to host IP address h.h.h.h is deleted.
n.n.n.n	2	Any route to host IP address n.n.n.n is deleted.

ipNetToMediaPhysAddress

The hardware address portion of an address table binding on the agent host (an entry in the ARP table). This is the same MIB variable as atPhysAddress.

Instance	Value	Action
f.1.n.n.n.n	hh:hh:hh:hh:hh:hh	For the interface with ifIndex f, any existing ARP table binding for IP address n.n.n.n is replaced with the binding (n.n.n.n, hh:hh:hh:hh:hh:hh). If a binding did not exist, the new binding is added. hh:hh:hh:hh:hh:hh is a 12-hexadecimal-digit hardware address.

ipNetToMediaNetAddress

The IP address corresponding to the hardware or physical address specified in ipNetToMediaPhysAddress. This is the same MIB variable as atNetAddress.

Instance	Value	Action
f.1.n.n.n.n	m.m.m.m	For the interface with ifIndex f, an existing ARP table entry for IP address n.n.n.n is replaced with IP address m.m.m.m.

ipNetToMediaType

The type of mapping from the IP address to the physical address.

Instance	Value	Action
f.1.n.n.n.n	1	For the interface with ifIndex f, for an existing ARP binding from IP address to physical address, the mapping type is set to 1, or other.
	2	For the interface with ifIndex f, for an existing ARP binding from IP address to physical address, the mapping type is set to 2, or invalid. As a side effect, the corresponding entry in the ipNetMediaTable is invalidated; that is, the interface is disassociated from this ipNetToMediaTable entry.
	3	For the interface with ifIndex f, for an existing ARP binding from IP address to physical address, the mapping type is set to 3, or dynamic.
	4	For the interface with ifIndex f, for an existing ARP binding from IP address to physical address, the mapping type is set to 4, or static.

snmpEnableAuthenTraps

Indicates whether the snmpd agent is configured to generate authenticationFailure traps.

Instance	Value	Action
0	1	The snmpd agent will generate authentication failure traps.
	2	The snmpd agent will not generate authentication failure traps.

smuxPstatus

The status of an SMUX protocol peer (used to delete SMUX peers).

Instance	Value	Action
n	1	snmpd agent does nothing.
	2	snmpd agent stops communicating with SMUX peer n.

smuxTstatus

The status of a SMUX MIB tree (used to delete MIB tree mounts).

Instance	Value	Action
l.m.m.m._ _ _ .p	1	snmpd agent does nothing.
	2	Unmounts SMUX mounting of MIB tree m.m.m... where l is the length of MIB tree instance and p is the smuxTpriority.

The following variables are the settable variables as defined in RFC 1229. The snmpd daemon allows the user to set these variables. The underlying device might not allow the setting of such variables. Check with each device to see what is and is not supported.

ifExtnsPromiscuous

The status of the promiscuous mode on a given device. This is used to enable and disable promiscuous mode on a given device. The snmpd action is final and complete. When snmpd is told to turn off, promiscuous mode is turned completely off regardless of the other applications on the machine.

Instance	Value	Action
n	1	Turns on the promiscuous mode for device n.
	2	Turns off the promiscuous mode for device n.

ifExtnsTestType

The test initiation variable. When this variable is set, the appropriate test is run for that device. An Object Identifier is the value of the variable. The specific value is dependent on the device type and the test that is to be run. Currently, the only defined test that snmpd knows to run is the testFullDuplexLoopBack test.

Instance	Value	Action
n	oid	Start the test specified by oid.

ifExtnsRcvAddrStatus

The address status variable. When this variable is set, the specified address comes into existence with the appropriate level of duration. snmpd only allows the setting of temporary addresses because it is not able to set device Object Data Manager (ODM) records and it is only allowed to set multicast or broadcast addresses.

Instance	Value	Action
n.m.m.m.m.m.m	1	Add the address as something other than a temporary or permanent address.
	2	Remove the address from usage.
	3	Add the address as a temporary address.
	4	Add the address as a permanent address.

The variables listed below are the settable variables as defined in RFC 1231. The snmpd daemon allows the user to set these variables. The underlying device might not allow the setting of such variables. You should check with each device to see what is supported.

dot5Commands

The command the token-ring device is toperform.

Instance	Value	Action
n	1	Does nothing. Returned.
	2	Tells the token-ring device to open.
	3	Tells the token-ring to reset.
	4	Tells the token-ring device to close.

dot5RingSpeed

The current ring speed or bandwidth.

Instance	Value	Action
n	1	An unknown speed.
	2	1 megabit ring speed.
	3	4 megabit ring speed.
	4	16 megabit ring speed.

dot5ActMonParticipate

The object specifies whether the device participates in the active monitor selection process.

Instance	Value	Action
n	1	Participates.
	2	Not participate.

dot5Functional

The functional mask that allows the token-ring device to specify what addresses it receives frames from.

Instance	Value	Action
n	m.m.m.m.m.m	Functional mask to be set.

The following complex timer manipulations variables are defined in the RFC as read-only but you are encouraged to make them read-write. Review the RFC to gain a full understanding of their interactions. snmpd allows the requestor to set them, but the device might not. Check the device driver documentation for more information. The variables are:

• dot5TimerReturnRepeat
• dot5TimerHolding
• dot5TimerQueuePDU
• dot5TimerValidTransmit
• dot5TimerNoToken
• dot5TimerActiveMon
• dot5TimerStandbyMon
• dot5TimerErrorReport
• dot5TimerBeaconTransmit
• dot5TimerBeaconReceive.

The SNMP daemon allows the user to set the following variables. The daemon uses the FDDI Station Management (SMT) 7.2 protocol standard to get the information and is determined at the microcode level. Check the microcode on the FDDI documentation to ensure that the SMT 7.2 microcode is being used.

fddimibSMTUserData

A variable holding 32 bytes of user information.

Instance	Value	Action
n	string	Stores 32 bytes of user information.

fddimibSMTConfigPolicy

The status of the configuration policies, specifically the hold policy usage.

Instance	Value	Action
n	0	Do not use the hold policy.
	1	Use the hold policy.

fddimibSMTConnectionPolicy

The status of the connection policies in the FDDI node. See RFC 1512 for more information about the specific settable values.

Instance	Value	Action
n	k	Defines the connection policies.

fddimibSMTTNotify

The timer, expressed in seconds, used in the Neighbor Notification protocol. It has a range of 2 seconds to 30 seconds, and its default value is 30 seconds.

Instance	Value	Action
n	k	Defines the timer value.

fddimibSMTStatRptPolicy

The status of the status reporting frame generation.

Instance	Value	Action
n	1	Indicates that the node generates status reporting frames for implemented events.
	2	Indicates that the node does not create status reporting frames.

fddimibSMTTraceMaxExpiration

This variable defines the maximum timer expiration value for trace.

Instance	Value	Action
n	k	Defines the maximum timer expiration in milliseconds.

fddimibSMTStationAction

This variable causes the SMT entity to take a specific action. See the RFC to get specific information about this variable.

Instance	Value	Action
n	k	Defines an action on the SMT entity. Values range from 1 to 8.

fddimibMACRequestedPaths

Defines the paths the medium access control (MAC) should be inserted.

Instance	Value	Action
n.n	k	Defines the requested path for the MAC.

fddimibMACFrameErrorThreshold

Threshold for when a MAC status report is generated. Defines the number of error that must occur before a report is generated.

Instance	Value	Action
n.n	k	Defines the number of errors that must be observed before a MAC status report is generated.

fddimibMACMAUnitdataEnable

This variable determines the value of the MA_UNITDATA_Enable flag in RMT. The default and initial value of this flag is true (1).

Instance	Value	Action
n.n	1	Marks the MA_UNITDATA_Enable flag true.
	2	Marks the MA_UNITDATA_Enable flag false.

fddimibMACNotCopiedThreshold

A threshold for determining when a MAC condition report is generated.

Instance	Value	Action
n.n	k	Defines the number of errors that must be observed before a MAC condition report is generated.

The following three variables are timer variables that are interactive among themselves. Before changing any of these variables, you should have a good understanding of their meaning as defined in RFC 1512.

• fddimibPATHTVXLowerBound
• fddimibPATHTMaxLowerBound
• fddimibPATHMaxTReq.

fddimibPORTConnectionPolicies

Specifies the connection policies for the specified port.

Instance	Value	Action
n.n	k	Defines the connection policies for the specified port.

fddimibPORTRequestedPaths

This variable is a list of permitted paths where each list element defines the port permitted paths. The first octet corresponds to `none', the second octet to `tree', and the third octet to `peer'.

Instance	Value	Action
n.n	ccc	Defines the port paths.

fddimibPORTLerCutoff

The link error rate estimate at which a link connection is broken. It ranges from 10**-4 to 10**-15 and is reported as the absolute value of the base 10 logarithm (default of 7).

Instance	Value	Action
n.n	k	Defines the port LerCutoff.

fddimibPORTLerAlarm

The link error rate estimate at which a link connection generates an alarm. It ranges from 10**-4 to 10**-15 and is reported as the absolute value of the base 10 logarithm of the estimate (default is 8).

Instance	Value	Action
n.n	k	Defines the port LerAlarm.

fddimibPORTAction

This variable causes the port to take a specific action. See the RFC to get specific information about this variable.

Instance	Value	Action
n	k	Defines an action on the defined port. The values range from 1 to 6.

Note: RFC 1213 describes all variables in the atEntry and ipNetToMediaEntry tables as read-write. Set support is implemented only for the atEntry variables atPhysAddress and atNetAddress, and the ipNetToMediaEntry variables ipNetToMediaPhysAddress, ipNetToMediaNetAddress, and ipNetToMediaType. To accept set requests that might specify the remaining unsupported attributes in these two tables, set requests for the remaining variables are accepted in atIfIndex and ipNetToMediaIfIndex. No error response is returned to the set request originator, but a subsequent get request will show that the original values are retained.

In the ipRouteEntry table, RFC 1213 describes all variables except ipRouteProtoas read-write. As mentioned above, set support is implemented only for the variables ipRouteDest, ipRouteNextHop, and ipRouteType. To accept set requests that might specify several unsupported route attributes, set requests for the remaining variables in the ipRouteEntry table are accepted: ipRouteIfIndex, ipRouteMetric1, ipRouteMetric2, ipRouteMetric3, ipRouteMetric4, ipRouteMetric5, ipRouteAge, and ipRouteMask. No error response is returned to the set request originator, but a subsequent get request will show that the original values are retained. The snmpd daemon does not coordinate routing with the routed daemon. If the gated daemon is running and has registered the ipRouteTable with the snmpd daemon, set requests to the ipRouteTable are not allowed.

RFC 1229 describes settable variables that snmpd allows. See the previous entries for actual deviations.

Examples

The following examples use the snmpinfo command. It is assumed that the snmpinfo default community name, public, has read-write access for the respective MIB subtree.

snmpinfo -m set sysContact.0="Primary contact: Bob Smith, office phone: 555-5555, 
beeper: 9-123-4567. Secondary contact: John Harris, phone: 555-1234." 

This command sets the value of sysContact.0 to the specified string. If an entry for sysContact.0 already exists, it is replaced.

snmpinfo -m set sysName.0="bears.austin.ibm.com" 

This command sets the value of sysName.0 to the specified string. If an entry for sysName.0 already exists, it is replaced.

snmpinfo -m set sysLocation.0="Austin site, building 802, lab 3C-23, southeast 
corner of the room." 

This command sets the value of sysLocation.0 to the specified string. If an entry for sysLocation.0 already exists, it is replaced.

snmpinfo -m set ifAdminStatus.2=2 

This command disables the network interface adapter which has the ifIndex of 2. If the assigned value is 1, the interface adapter is enabled.

snmpinfo -m set atPhysAddress.2.1.192.100.154.2=02:60:8c:2e:c2:00
snmpinfo -m set ipNetToMediaPhysAddress.2.1.192.100.154.2=02:60:8c:2e:c2:00 

These two commands change the hardware address in the ARP table entry for 192.100.154.2 to 02:60:8c:2e:c2:00. These two commands affect the same ARP table entry. The MIB variable atPhysAddress is a deprecated variable and is being replaced with the MIB variable ipNetToMediaPhysAddress. Thus, atPhysAddress and ipNetToMediaPhysAddress access the same structure in the TCP/IP kernel ARP table.

snmpinfo -m set atNetAddress.2.1.192.100.154.2=192.100.154.3 
snmpinfo -m set ipNetToMediaNetAddress.2.1.192.100.154.2=192.100.154.3 

These commands change the IP address in the ARP table entry for 192.100.154.2 to 192.100.154.3. These two commands affect the same ARP table entry. The MIB variable atNetAddress is a deprecated variable and is being replaced with the MIB variable ipNetToMediaNetAddress. Thus, atNetAddress and ipNetToMediaNetAddress access the same structure in the TCP/IP kernel ARP table.

snmpinfo -m set ipForwarding.0=1 

This command sets the TCP/IP kernel so that it can forward packets if the agent host has more than one interface that is up. If the host has only one active interface, then the set request fails and the snmpd agent returns the error, badValue.

snmpinfo -m set ipDefaultTTL=50 

This command allows an IP datagram using default time-to-live (TTL) to pass through up to 50 gateways before being discarded. When each gateway processes a datagram, the gateway subtracts 1 from the time-to-live field. In addition, each gateway decrements the time-to-live field by the number of seconds the datagram waited for service at that gateway before passing the datagram on to the next destination.

snmpinfo -m set ipRouteDest.192.100.154.0=192.100.154.5 

This command sets the destination IP address of the route associated with 192.100.154.0 to the IP address 192.100.154.5, assuming route 192.100.154 already existed.

snmpinfo -m set ipRouteNextHop.192.100.154.1=129.35.38.47 

This command sets a route to host 192.100.154.1 using the gateway host 129.35.38.47, assuming route 192.100.154.1 already existed.

snmpinfo -m set ipRouteNextHop.192.100.154.0=192.100.154.7 

This command sets a route to the class C network 192.100.154 using the gateway host 192.100.154.7, assuming route 192.100.154.0 already existed. Note that the host part of the address must be 0 to indicate a network address.

snmpinfo -m set ipRouteType.192.100.154.5=2 

This command deletes any route to host 192.100.154.5.

snmpinfo -m set ipRouteDest.129.35.128.1=129.35.128.1
                ipRouteType.129.35.128.1=3
             ipRouteNextHop.129.35.128.1=129.35.128.90

This command creates a new route from host 129.35.128.90 to 129.35.128.1 as a gateway.

snmpinfo -m set ipNetToMediaType.2.1.192.100.154.11=4

This command sets the ARP table entry for 192.100.154.11 to static.

snmpinfo -m set snmpEnableAuthenTraps=2

This command causes the snmpd agent on the specified host to not generate authenticationFailure traps.

snmpinfo -m set smuxPstatus.1=2

This command invalidates the SMUX peer 1. The result is that the connection between the snmpd agent and this SMUX peer is terminated.

snmpinfo -m set smuxTstatus.8.1.3.6.1.2.1.4.21.0=2 

This command invalidates or removes the mounting of the SMUX tree 1.3.6.1.2.1.4.21, the ipRoute Table. The first number in the instance indicates the number of levels in the SMUX tree identifier. The final number in the instance indicates the smuxTpriority. In this example, there are 8 levels in the SMUX tree identifier: 1.3.6.1.2.1.4.21. The priority, 0, is the highest priority.

snmpinfo -m set ifExtnsPromiscuous.1=1 ifExtnsPromiscuous.2=2 

This command turns on promiscuous mode for the first device in the interfaces table and turns off promiscuous mode for the second device in the interfaces table.

snmpinfo -m set ifExtnsTestType.1=testFullDuplexLoopBack  

This command starts the testFullDuplexLoopBack test on interface 1.

snmpinfo -m set ifExtnsRcvAddrStatus.1.129.35.128.1.3.2=2   

This command tells interface 1 to remove physical address 129.35.128.1.3.2 from its list of acceptable addresses.

snmpinfo -m set dot5Commands.1=2

This command tells the first interface to do an open.

snmpinfo -m set dot5RingSpeed.1=2 

This command tells the first interface to set it ring speed to 1 megabit.

snmpinfo -m set dot5ActMonParticipate.1=1 

This command tells the first interface to participate in the active monitor selection process.

snmpinfo -m set dot5Functional.1=255.255.255.255.255.255

This command sets the functional address mask to allow everything.

snmpinfo -m set fddimibSMTUserData.1="Greg's Data"  

This command sets the user data on the first SMT entity to "Greg's Data".

snmpinfo -m set fddimibMACFrameErrorThreshold.1.1=345

This command sets the threshold for frame errors to 345 on the first MAC of the first SMT entity.

Note: All of the variables described previously fall into one of the listed methods used to set the variable.

See Address Resolution Protocol and Internet Addresses for more information on protocols and Internet addresses.