See that a link switch is functioning properly?

[fluque]

Hi,

I'm trying to monitor several of the main links to backbone switch, to see if there are any problems with any links.
The variables that I am monitoring are IfAdminStatus and IfOperStatus, but I'm not sure that is correct, and that triguers should use to see if a link has been dropped?

Thanks very much,

Regards,

Francisca

[troffasky]

ifAdminStatus is not the one you want, it'll change when the port is disabled or enabled by the switch administrator. ifOperStatus is going to be more useful to you, basically it tells you if the link is up or down.

[fluque]

Redundant links.

Thanks.

In the case of redundant links Spaning tree, this variable is correct, or is there another more appropriate MIB variable?

[troffasky]

It Depends. Some switches offer a lot more information than others via SNMP, eg HP Procurve 2626 has ~19000 items available via SNMP, vs ~6000 items on a Linksys SFE2000P, and both of these are 24 port switches. I suggest you snmpwalk your intended target and see if it supports what data you're after.

[troffasky]

The following OIDs may be of interest:

BRIDGE-MIB::dot1dStpPortState

BRIDGE-MIB::dot1dStpPortEnable

Eg from a Procurve 2650 with STP enabled [note that you won't be able to see these OIDs until STP is enabled]:

BRIDGE-MIB::dot1dStpPortState.32 = INTEGER: disabled(1)
BRIDGE-MIB::dot1dStpPortState.33 = INTEGER: forwarding(5)

From BRIDGE-MIB:

dot1dStpPortState OBJECT-TYPE
    SYNTAX      INTEGER {
                    disabled(1),
                    blocking(2),
                    listening(3),
                    learning(4),
                    forwarding(5),
                    broken(6)
                }
    MAX-ACCESS  read-only
    STATUS      current
    DESCRIPTION
        "The port's current state, as defined by application of
        the Spanning Tree Protocol.  This state controls what
        action a port takes on reception of a frame.  If the
        bridge has detected a port that is malfunctioning, it
        will place that port into the broken(6) state.  For
        ports that are disabled (see dot1dStpPortEnable), this
        object will have a value of disabled(1)."
    REFERENCE
        "IEEE 802.1D-1998: clause 8.5.5.2"
    ::= { dot1dStpPortEntry 3 }