SNMP

Hi There,

Hope everything is going well for everyone. 

I was wondering whether it's possible to grab all the mac entries  on an SM units bridge table ?

Thanks in advance,

Hit .1.3.6.1.4.1.17713.21.1.2.50.1 with snmpwalk.  Returns a table with four values for each neighbor.  ....50.1.1 is interface, 'br-lan' in bridging mode.  50.1.2 is the MAC addresses, 50.1.3 is what port (e.g. LAN) and 50.1.4 is aging time.

# snmpwalk -v2c -cpublic 10.12.12.31 .1.3.6.1.4.1.17713.21.1.2.50.1


CAMBIUM-PMP80211-MIB::camSTABrTabBridgeName.1 br-lan
CAMBIUM-PMP80211-MIB::camSTABrTabBridgeName.2 br-lan
CAMBIUM-PMP80211-MIB::camSTABrTabDevMACAddress.1 00:04:56:C3:50:62
CAMBIUM-PMP80211-MIB::camSTABrTabDevMACAddress.2 94:10:3E:93:50:D5
CAMBIUM-PMP80211-MIB::camSTABrTabDevPort.1 Own
CAMBIUM-PMP80211-MIB::camSTABrTabDevPort.2 LAN
CAMBIUM-PMP80211-MIB::camSTABrTabAgingTime.1 0
CAMBIUM-PMP80211-MIB::camSTABrTabAgingTime.2 18

Takes a bit of parsing to get exactly what you want sometimes, but the data is there.

j

Hey , thanks for the info . This is exactly what I was looking for but I'm having a small issue which I think is MIB related.  

I've dumped all the enterprise MIBs into the only folder I could find containing other mibs. "/usr/share/snmp/mibs". 

Below is the error I'm getting back from snmpwalk.

[root@localhost mibs]# snmpwalk -v2c -cg_wireless 10.4.23.218 .1.3.6.1.4.1.17713.21.1.2.50.1

SNMPv2-SMI::enterprises.17713.21.1.2.50.1 = No Such Instance currently exists at this OID

If you use the numeric representation (as you did) then the MIB file isn't consulted.  (if you use the text version, like 'camSTABrTabDevMACAddress.1', it is - then /usr/share/snmp/mibs is almost always the right place for the MIB files, just make sure they're readable by all users)

The error message is because the client device doesn't recognize the OID.

What firmware is on the radio?  Bridge table MACs weren't exposed on many earlier releases.

j

It's a PMP450 running version 13.3. 

Well that's the problem, I mistakenly gave you the OID for ePMP...

For PMP450 you should walk .1.3.6.1.4.1.161.19.3.3.4.1.1 - the list of MACs, including the SM itself.  (back up a level to .1.3.6.1.4.1.161.19.3.3.4.1 and you get the MACs, the LUIDs associated with each, etc)

j

Wow , awesome man .. much apreciated.  Working like swiss time piece now :D

-steph

I presume the AP will contain a list of all the MAC addresses which each SM contains connecting to it ? So in short , instead of running snmpget on each and every SM , I can just run it against the AP as well ?

-steph

Correct.  Try snmpwalk of .1.3.6.1.4.1.161.19.3.3.4.1 and you'll get MACs, LUID through which each is seen, etc.

Both approaches will work, depending on what your goal is it may be easier or more sensible to do one over the other.  (I poll both on our network)

j

1 Like

Oh, just to clarify:  This presumes you're bridging.  If the SM is NATting then you won't see client devices at the AP.  Also, the AP and the SM may not always contain exactly the same MACs, depending on the timeouts on each device and probably other factors.

For our purposes, I scan bridge table on both devices partly because we poll APs every 10 minutes on the 0s and SMs every 10 minutes on the 5s, (so in a sense I get twice the polling rate on neighbor MACs) and I stuff every MAC seen everywhere (including routers) into a database for later reference.

j

Awesome , much appreciated.

Is there perhaps a way to retrieve the equipment type via SNMP ? Like for instance which model number the unit belongs to (PMP100 , 430 or 450 ) ?

.1.3.6.1.4.1.161.19.3.3.1.6 is the boxDeviceType field, an example content might be "3.6GHz MIMO OFDM - Multipoint - Subscriber Module", while the next field .1.3.6.1.4.1.161.19.3.3.1.7 is the BoxDeviceTypeID field, with simply "AP" or "SM".

.1.3.6.1.4.1.161.19.3.3.1.10 is boxFrequency (frequency band the gear runs in, NOT the specific frequency it's currently using) and .1.3.6.1.4.1.161.19.3.3.1.11 is platformVer, telling you if it's a P10, P11, etc hardware board version.

http://support.cambiumnetworks.com/framed/onlinetools/ is very handy.  Lets you select almost any of the Cambium-related MIBs and browse through them, including descriptions of the format of the values that may be read or written for each.  (There are three separate MIBs applicable here - PMP Common, PMP Access Point, and PMP Subscriber Module)

And if you have the MIBs correctly installed, you should be able to use something like "snmpwalk -v 2c -c public 10.20.30.40 whisproot | less" and scroll through the complete dump of cambium-specific SNMP fields with names. ('public' is the community string, obviously that and the IP are up to you to get correct)

All these fields are available on older FSK Canopy equipment as well - except for fields only applicable to one or the other (dual polarity, etc) they are very similar.

j

1 Like

Thanks for all the info man , really appreciate it.