SNMP on Each SM


I am trying to set up MRTG and its working fine for each AP but I cannot get any information from an SM. I have been using the following command on the linux box (debian 3.0 tesing). I can get a full set of system information from the AP but I only get Timeout: No response from the SM. If I change the RF public on the SM to I am able to get information from the device. I do not have enought 192.168.14. ip addresses for all of my SM’s. Is this a bug?

snmpwalk -v 2c -c testing1 <ipaddress>

(All are on the same switch and I can ping between all the devices and pass traffic on http, ftp, telnet.)

Linux server with snmp client software and mrtg
IP Address:

RF Public Network Interface Configuration IP Address:
SNMP Community: testing1
SNMP Accessing Subnet:

RF Public Network Interface Configuration IP Address:
SNMP Community: testing1
SNMP Accessing Subnet:

Matthew Jenkins
Nor Cal Broadband, Inc
Newcastle, CA 95658

Do you have more than one ethernet interface on the linux box? That can cause problems. You can verify the packets are going out the right place with tcpdump.

Also you may not want to do a full snmp of all the SMs too quickly. You’ll end up eating all the bandwidth to find out things the AP already has. 5 min bandwidht stats on the AP is good but you might want to do bandwidth stats and rssi and jitter on SM’s once an hour or so or rotate it so ever 15 minutes you do 1/4 of the units on an AP.

You do need a way to tell if they bandwidth between two SM’s is much higher than the SM->AP->Inet since thats a sign that a client has a virus.

thogard wrote:
You'll end up eating all the bandwidth to find out things the AP already has.

Thograd has a very good point. Notice all the info on the "sessions" page on the AP? All of that information is available via SNMP from the AP on a per LUID basis. I'm currently monitoring session/registration count, RSSI, and jitter on each SM by SNMP quering the AP only. The only thing I'd have to query the SM for is ethernet throughput per SM.

Yes I am sure the traffic is going out the correct eth card. The problem was the subnet mask on the linux box. It needs to be set to

ahull wrote:

The only thing I’d have to query the SM for is ethernet throughput per SM.

The throughput per SM is the only traffic we want to monitor to start. We may later want to monitor rssi and jitter but then it would be best to do it per SM since the LUID# can change for an SM but the ip doesnt.


Can soemone post a sample config they are using to get RSSI, Jitter, Session, etc for SM’s from the AP?

I have been struggling with this for too long… Any help would be great.



Target[ap-rssi]: .

Target[ap-jitter]: .

Target[sm-count]: .

Here is an excerpt from my mrtg.conf for an SM.

Note that if you are using Linux you need to put the absolute path on the LoadMibs line or the rssi and jitter will not work. It took me forever to figure that out.

############### < Device = customer_name > #######################################

### customer_name :Ethernet Interface Traffic
Title[customer_ip-eth_int]:Traffic Analysis for customer_name - Ethernet Interface
PageTop[customer_ip-eth_int]:<H1><A Href=“http://customer_ip"target=”_blank">customer_name - Ethernet Interface</A></H1>
<TR><TD>Device:</TD> <TD>Canopy Subscriber Module</TD></TR>
<TR><TD>Max Speed:</TD> <TD>7.5 MBytes/s</TD></TR>
<TR><TD>Description:</TD> <TD>customer_name </TD></TR>

### customer_name :RF Interface Traffic
Title[customer_ip-rf_int]:Traffic Analysis for customer_name - RF Interface
PageTop[customer_ip-rf_int]:<H1><A Href=“http://customer_ip"target=”_blank">customer_name - RF Interface</A></H1>
<TR><TD>Device:</TD> <TD>Canopy Subscriber Module</TD></TR>
<TR><TD>Max Speed:</TD> <TD>7.5 MBytes/s</TD></TR>
<TR><TD>Description:</TD> <TD>customer_name </TD></TR>

### customer_name :Rssi
Title[customer_ip-rssi]:RSSI Analysis for customer_name
Options[customer_ip-rssi]:gauge, nopercent, absolute
LegendI[customer_ip-rssi]: RSSI:
LegendO[customer_ip-rssi]: RSSI:
PageTop[customer_ip-rssi]:<H1><A Href=“http://customer_ip"target=”_blank">customer_name - RSSI</A></H1>
<TR><TD>Device:</TD> <TD>Canopy Subscriber Module</TD></TR>
<TR><TD>Max Speed:</TD> <TD>7.5 MBytes/s</TD></TR>
<TR><TD>Description:</TD> <TD>customer_name </TD></TR>

### customer_name :Jitter
Title[customer_ip-jitter]:Jitter Analysis for customer_name
Options[customer_ip-jitter]:gauge, nopercent, absolute
YLegend[customer_ip-jitter]: Jitter
LegendI[customer_ip-jitter]: Jitter:
LegendO[customer_ip-jitter]: Jitter:
PageTop[customer_ip-jitter]:<H1><A Href=“http://customer_ip"target=”_blank">customer_name - Jitter</A></H1>
<TR><TD>Device:</TD> <TD>Canopy Subscriber Module</TD></TR>
<TR><TD>Max Speed:</TD> <TD>7.5 MBytes/s</TD></TR>
<TR><TD>Description:</TD> <TD>customer_name </TD></TR>

I've just updated to 2.10-r22 and I cannot get cnMaestro to correctly name the onboarded device, using the name that has been set in the router.

Can anyone confirm that when they onboard an R200 device with an edited hostname, that the device's name gets used instead of the generic name "cnPilot R200-{last 6 of MAC}"?