ifDescr is now displayed Hex-STRING

[renaatski]

Cacti was running great until a couple of days,

When looking in the traffic data query for a host now, I notice that since a couple of days, the ifDescr field is no longer "Fast ethernet bla bla" , but a Hex-STRING "00 11 AB ...." . That obviously is not what I want as a graph title (for one it's far too long, and two it's unreadable)

When I do an snmpwalk on commandline, I gives me back the same stuff. Unfortunately, cacti doesn't seem to be trying to decode the Hex part .

I noticed in /var/log/yum.log that my sys-admin has updated net-snmp from 5.1.2 to 5.2.1.

Anyone else having this problem and know how to solve this ? It would be greatly appreciated!

Kind regards,

Renaat

[TheWitness]

This is typically caused by competing MIB files causing issues with data display. You likely either added a MIB file or changed versions of Net-SNMP causing this problem. You should start to backout some of the mib files. I had the EXACT same problem. I think the MIB file that was causing the problem was an RFCxxxx one.

TheWitness

[renaatski]

Rolled back the MIBS from 5.1.2-1 but still no joy..

But I found another thing, apparently php_snmp is no longer used by cacti since the upgrade of net-snmp.

My problem is the exact same thing as in http://forums.cacti.net/viewtopic.php?t ... ht=phpsnmp !

Will roll back to previous version since that apparently is the solution for the moment.

However, there is something to be said when one would not want to use php_snmp. Apparently the command-line snmp tools break some responses up in different lines:

Verbose query for interfaces from within cacti without php_snmp:


+ Located input field 'ifDescr' [walk]
+ Executing SNMP walk for data @ '.1.3.6.1.2.1.2.2.1.2'
+ Found item [ifDescr='HEX-00:4D:53:20:54:43:50:20:4C:6F:6F:70:62:61:63:6B:20'] index: 1 [from value]
+ Found item [ifDescr='69:6E:74:65:72:66:61:63:65:00'] index: 69 6E 74 65 72 66 61 63 65 00 [from value]
+ Found item [ifDescr='HP NC6770 Gigabit Server Adapter'] index: 16777219 [from value]
+ Found item [ifDescr='HEX-00:48:50:20:4E:43:33:31:36:33:20:46:61:73:74:20:45'] index: 16777220 [from value]
+ Found item [ifDescr='74:68:65:72:6E:65:74:20:4E:49:43:00'] index: 74 68 65 72 6E 65 74 20 4E 49 43 00 [from value]
+ Found item [ifDescr='HEX-00:48:50:20:4E:43:33:31:36:33:20:46:61:73:74:20:45'] index: 16777221 [from value]
+ Found item [ifDescr='74:68:65:72:6E:65:74:20:4E:49:43:00'] index: 74 68 65 72 6E 65 74 20 4E 49 43 00 [from value]

Notice how it seems to think that for each line with Hex-STRING there are two items found ? (this is besides the fact that cacti doesn't seem to try to hex-decode)

Kind regards,

Renaat

[TheWitness]

I'm a bit confused. The way Cacti works is that if you have php_snmp made with your php package, Cacti will ALWAY's use it first. And now that it contains functions for v1, v2c, and v3 (Cacti 0.9) it will always use it.

So to say that Cacti doesn't use it means that you have an rpm or have made it without php_snmp.

The issue with Hex responses is due to, what I believe to be either an net-snmp bug or a conflicting mib files overlay. If you delete all your mib files (back them up first), and then rerun the walk from the command line, what do you get?

Also, please make sure you only have 1 mib library and not 2. This can also cause some confusion. I had lots of problems early on myself.

TheWitness

[renaatski]

Cacti was using php_snmp, or is trying to, but when doing

[root@myhost ]# php -v
PHP Warning: Unknown(): Unable to load dynamic library '/usr/lib/php4/snmp.so' - /usr/lib/php4/snmp.so: undefined symbol: usmAES192PrivProtocol in Unknown on line

I did not have that error when I installed this system! I seems to have something to do with net-snmp 5.2.1


For as far as the Hex-STRING command-line issue, I renamed the 5.2.1 /usr/share/snmp/mibs to /usr/share/snmp/mibs.old en put back the mibs directory from 5.1.2

That doesn't change the issue:

[root@myhost snmp]# snmpwalk -c community -v 1 anotherhost ifDescr
RFC1213-MIB::ifDescr.1 = Hex-STRING: 4D 53 20 54 43 50 20 4C 6F 6F 70 62 61 63 6B 20
69 6E 74 65 72 66 61 63 65 00
RFC1213-MIB::ifDescr.16777219 = STRING: "HP NC6770 Gigabit Server Adapter"
RFC1213-MIB::ifDescr.16777220 = Hex-STRING: 48 50 20 4E 43 33 31 36 33 20 46 61 73 74 20 45
74 68 65 72 6E 65 74 20 4E 49 43 00
RFC1213-MIB::ifDescr.16777221 = Hex-STRING: 48 50 20 4E 43 33 31 36 33 20 46 61 73 74 20 45
74 68 65 72 6E 65 74 20 4E 49 43 00


I even tried using the snmpwalk binary from 5.1.2

Regards,

Renaat

[TheWitness]

Please read carefully, DELETE the MIBS! The issue with net-snmp 5.2.1 is likely due to a bad rpm, or did you make yourself?

TheWitness

[renaatski]

I'm sorry if I fail to understand :s

[root@srv mibs]# pwd
/usr/share/snmp/mibs
[root@srv mibs]# ls -al
total 12
drwxr-xr-x 2 renaat users 4096 May 2 11:50 .
drwxr-xr-x 6 root root 4096 May 2 10:40 ..
-rw-r--r-- 1 root root 0 May 2 11:50 .index
[root@srv mibs]#

[root@srv mibs]# snmpwalk -c community -v 1 srv .1.3.6.1.2.1.2.2.1.2
iso.3.6.1.2.1.2.2.1.2.1 = Hex-STRING: 4D 53 20 54 43 50 20 4C 6F 6F 70 62 61 63 6B 20
69 6E 74 65 72 66 61 63 65 00
iso.3.6.1.2.1.2.2.1.2.16777219 = STRING: "HP NC6770 Gigabit Server Adapter"
iso.3.6.1.2.1.2.2.1.2.16777220 = Hex-STRING: 48 50 20 4E 43 33 31 36 33 20 46 61 73 74 20 45
74 68 65 72 6E 65 74 20 4E 49 43 00
iso.3.6.1.2.1.2.2.1.2.16777221 = Hex-STRING: 48 50 20 4E 43 33 31 36 33 20 46 61 73 74 20 45
74 68 65 72 6E 65 74 20 4E 49 43 00


I used the RPMs from Fedora, automatic via yum

Thanks for the quick replies! (must be nighttime for you now ...)

[TheWitness]

Can you run the following as root to see if there are other libraries out there:

Code: Select all

find / -name *.mib -print

Also, when you restore the MIBS and run from the command line, are they still Hex?

TheWitness

p.s. I have to go to work now. It's 6:16am our time.

[renaatski]

Hi ahain,

I did a search earlier, the only mibs directory on my system is /usr/share/snmp/mibs.

I just did a roll-back of:

net-snmp-libs
net-snmp
net-snmp-utils

and put back the versions I previously had installed. The mibs are also back the way they were (verified against backup)

[root@srv /]# snmpwalk -c community -v 1 srv .1.3.6.1.2.1.2.2.1.2
RFC1213-MIB::ifDescr.1 = Hex-STRING: 4D 53 20 54 43 50 20 4C 6F 6F 70 62 61 63 6B 20
69 6E 74 65 72 66 61 63 65 00
RFC1213-MIB::ifDescr.16777219 = STRING: "HP NC6770 Gigabit Server Adapter"
RFC1213-MIB::ifDescr.16777220 = Hex-STRING: 48 50 20 4E 43 33 31 36 33 20 46 61 73 74 20 45
74 68 65 72 6E 65 74 20 4E 49 43 00
RFC1213-MIB::ifDescr.16777221 = Hex-STRING: 48 50 20 4E 43 33 31 36 33 20 46 61 73 74 20 45
74 68 65 72 6E 65 74 20 4E 49 43 00

Weird weird weird

On the other hand now, php -v now comes back without snmp.so warnings. Also cacti reports PHP SNMP as functional again. PHP SNMP not being functional is definately due to net-snmp 5.2.1.

The verbose query also behaves somewhat different, but still shows hex entries:

+ Located input field 'ifDescr' [walk]
+ Executing SNMP walk for data @ '.1.3.6.1.2.1.2.2.1.2'
+ Found item [ifDescr='HEX-00:4D:53:20:54:43:50:20:4C:6F:6F:70:62:61:63:6B:20:69:6E:74:65:72:66:61:63:65:00'] index: 1 [from value]
+ Found item [ifDescr='HEX-00:42:72:6F:61:64:63:6F:6D:20:4E:65:74:58:74:72:65:6D:65:20:47:69:67:61:62:69:74:20:45:74:68:65:72:6E:65:74:00'] index: 65539 [from value]
+ Found item [ifDescr='HEX-00:42:72:6F:61:64:63:6F:6D:20:4E:65:74:58:74:72:65:6D:65:20:47:69:67:61:62:69:74:20:45:74:68:65:72:6E:65:74:20:23:32:00'] index: 65540 [from value]
+ Found item [ifDescr='WAN (PPP/SLIP) Interface'] index: 262149 [from value]

Notice how it didn't breaks up the lines now (by using php snmp support)

This really IS getting confusing :s

Thanks,
Renaat

PS: a good monday at work then

[TheWitness]

If you have the environment variable MIBS=ALL either in the snmpd.conf or on the system, please remove it.

TheWitness

[renaatski]

I thought this was a long shot, but indeed my /etc/bashrc contained an export for MIBS=ALL

logged out and backin, and an snmpwalk now returns:

[root@srv ~]# snmpwalk -c community -v 1 srv .1.3.6.1.2.1.2.2.1.2
IF-MIB::ifDescr.1 = STRING: MS TCP Loopback interface
IF-MIB::ifDescr.16777219 = STRING: HP NC6770 Gigabit Server Adapter
IF-MIB::ifDescr.16777220 = STRING: HP NC3163 Fast Ethernet NIC
IF-MIB::ifDescr.16777221 = STRING: HP NC3163 Fast Ethernet NIC

Then restarted apache, and whoops, from within cacti (with PHP SNMP by using net-snmp 5.1.2-11):

+ Executing SNMP walk for data @ '.1.3.6.1.2.1.2.2.1.2'
+ Found item [ifDescr='MS TCP Loopback interface'] index: 1 [from value]
+ Found item [ifDescr='HP NC6770 Gigabit Server Adapter'] index: 16777219 [from value]
+ Found item [ifDescr='HP NC3163 Fast Ethernet NIC'] index: 16777220 [from value]
+ Found item [ifDescr='HP NC3163 Fast Ethernet NIC'] index: 16777221 [from value]


Great great great, but now what does mean ? Because in the docs it is stated that MIBS=ALL is required... so what gives ?

Already a big thank you for narrowing this down, oh and btw, I truly think cacti has a great potential! It just really does!

Kind regards,

Renaat

[TheWitness]

The documentation is correct on the Web site. It had been in error for some time. The MIBS environment variable causes problems. Forgot that rebooting is sometimes required or at least a restart of Apache.

TheWitness