Manual port descriptions overwritten but SNMPwalk data is useless

[richard.orton]

I have a number of Dlink 1100 series switches which are setup in my Libre instance, the port descriptions as set in the switch are not being pulled into Libre (a fault of the switch, if I SNMP Walk the switch, the ports just come back with ‘port1, port2’ etc - no names are present in SNMP even though I can see them in the switch gui config.

Not a problem, as I can manually add the names into Libre, which works fine, but then they are getting overwritten when SNMP grabs data from the switch, it pulls in the non descript SNMP names, overwriting my manual entries.

I understand that the preference would be to pull in the descriptions from the switch using SNMP, but in this example, its not working, so was hoping there is a way I can stop SNMP pulling in the ‘empty’ port data from the switch and stop overwriting my manual entries?

[DBMandrake]

I presume you can’t configure port descriptions in the 1100 series ?

Most of our switches are D-Link - all the newer ones let you name ports in the switch’s own Web UI and those names then get updated on LibreNMS automatically on the next 5 minute poll interval.

Some of our older switches don’t have this ability though.

[DBMandrake]

I just realised that we do actually have a DGS-1100-08PV2 at a remote site that is in LibreNMS.

It does have the option to name the interface:

However like you, when I set a custom name then manually do a discovery and poller run it doesn’t pick up the name in LibreNMS.

This means either (a) the switch doesn’t provide port names via SNMP or (b) the D-Link poller in LibreNMS doesn’t know how to get port names for this model of switch and would need to be updated to do so.

All the other models of D-Link we use which have the ability to name ports do show the correct custom port names in LibreNMS.

If you go to the hamburger button then “capture”, then SNMP then run, you’ll get a capture that looks similar to this:

.1.3.6.1.2.1.1.1.0 = STRING: "DGS-1100-08PV2 Gigabit Ethernet Switch"
.1.3.6.1.2.1.1.2.0 = OID: .1.3.6.1.4.1.171.10.173.4.1
.1.3.6.1.2.1.1.3.0 = Timeticks: (292628500) 33 days, 20:51:25.00
.1.3.6.1.2.1.1.4.0 = ""
.1.3.6.1.2.1.1.5.0 = STRING: "Switch Name"
.1.3.6.1.2.1.1.6.0 = STRING: "Switch Location"
.1.3.6.1.2.1.1.7.0 = INTEGER: 2
.1.3.6.1.2.1.1.8.0 = Timeticks: (292628500) 33 days, 20:51:25.00
.1.3.6.1.2.1.2.1.0 = INTEGER: 8
.1.3.6.1.2.1.2.2.1.1.1 = INTEGER: 1
.1.3.6.1.2.1.2.2.1.1.2 = INTEGER: 2
.1.3.6.1.2.1.2.2.1.1.3 = INTEGER: 3
.1.3.6.1.2.1.2.2.1.1.4 = INTEGER: 4
.1.3.6.1.2.1.2.2.1.1.5 = INTEGER: 5
.1.3.6.1.2.1.2.2.1.1.6 = INTEGER: 6
.1.3.6.1.2.1.2.2.1.1.7 = INTEGER: 7
.1.3.6.1.2.1.2.2.1.1.8 = INTEGER: 8
.1.3.6.1.2.1.2.2.1.2.1 = STRING: "port1"
.1.3.6.1.2.1.2.2.1.2.2 = STRING: "port2"
.1.3.6.1.2.1.2.2.1.2.3 = STRING: "port3"
.1.3.6.1.2.1.2.2.1.2.4 = STRING: "port4"
.1.3.6.1.2.1.2.2.1.2.5 = STRING: "port5"
.1.3.6.1.2.1.2.2.1.2.6 = STRING: "port6"
.1.3.6.1.2.1.2.2.1.2.7 = STRING: "port7"
.1.3.6.1.2.1.2.2.1.2.8 = STRING: "port8"
.1.3.6.1.2.1.2.2.1.3.1 = INTEGER: 6
.1.3.6.1.2.1.2.2.1.3.2 = INTEGER: 6
.1.3.6.1.2.1.2.2.1.3.3 = INTEGER: 6
.1.3.6.1.2.1.2.2.1.3.4 = INTEGER: 6
.1.3.6.1.2.1.2.2.1.3.5 = INTEGER: 6
.1.3.6.1.2.1.2.2.1.3.6 = INTEGER: 6
.1.3.6.1.2.1.2.2.1.3.7 = INTEGER: 6
.1.3.6.1.2.1.2.2.1.3.8 = INTEGER: 6

(This is only a partial capture for illustration)

You’ll note it still says Port8 above and none of the rest of the capture that I haven’t posted has the custom port name either.

Unfortunately to me it looks like this model of switch does not make custom port names available over SNMP just naming them Port1 to Port8.

You’re right that an option to prevent port names being overwritten on a port due to useless SNMP data would be useful as we do have quite a few switches where there is no option to customise the port name in the switch itself. It does seem odd to have a text entry box to customise the port name but no way to prevent the next poll from overwriting it.

[richard.orton]

Hi, thanks for confirming, yep, I did the snmp walk and saw the same - my switches are first gen too, I notice you have the v2 of the switch, shame to see that is still a problem with the newer gen switch.

Hopefully someone may reply and let me know if there is a way to stop the overwriting of the port names, not sure if there is a place to make such suggestions?

[DBMandrake]

@richard.orton

Hi, thanks for confirming, yep, I did the snmp walk and saw the same - my switches are first gen too, I notice you have the v2 of the switch, shame to see that is still a problem with the newer gen switch.

We only have one of those switches in a small remote site with one PC and two access points.

All our other D-Link switches are 24 port or bigger rack units, and of the ones that let you name an interface they all report it correctly via SNMP so it’s disappointing and puzzling that the 1100 supports SNMP but returns useless default port names. There are no firmware updates available either so I guess we’re stuck with its limited SNMP implementation.