snmpwalk IfAlias not working for a few routers

[Pingreply]

I'm using Cacti with a bunch of Juniper MX-routers and on a few routers I've got no IfAlias.
Doing snmpwalk on the shell works and I'm getting the IfAlias information.
If I let Cacti do the snmp-walk, I'm getting:

Located input field 'ifAlias' [walk]
+ Executing SNMP walk for data @ '.1.3.6.1.2.1.31.1.1.1.18'
+ Located input field 'ifType' [walk]

It's just skipping the IfAlias. When I try this on another router with the same bunch of interfaces and specs, it's working.
On another router, a Juniper M320, I'm also getting no IfAlias.

Anyone has an idea for this?
Thanks in advance!

[gandalf]

And was does a native snmpwalk provide for that very system?
R.

[Pingreply]

When I do this on the shell, it works:

$ snmpwalk -v2c -c <community> <router> .1.3.6.1.2.1.31.1.1.1.18
IF-MIB::ifAlias.1 = STRING:
IF-MIB::ifAlias.4 = STRING:
IF-MIB::ifAlias.5 = STRING:
IF-MIB::ifAlias.6 = STRING:
IF-MIB::ifAlias.7 = STRING:
IF-MIB::ifAlias.8 = STRING:
IF-MIB::ifAlias.9 = STRING:
IF-MIB::ifAlias.10 = STRING:
<etc>

On Cacti, when I select the router in Console -> Devices -> <router> -> Verbose Query on the interface statistics, it skips IfAlias. It only says:

<snip>
+ Located input field 'ifAlias' [walk]
+ Executing SNMP walk for data @ '.1.3.6.1.2.1.31.1.1.1.18'
+ Located input field 'ifType' [walk]
+ Executing SNMP walk for data @ '.1.3.6.1.2.1.2.2.1.3'
<snip>

The box has plenty of interfaces, so maybe it's getting a problem with memory limits in PHP.
But for another Juniper, with the same amount of interfaces, it works.

[Pingreply]

Some more info:

- Problem isn't with php memory limit
- When I use SNMP v1, I'm getting the IfAlias-info. With V2 I'm not getting the info

[gandalf]

When I do this on the shell, it works:

$ snmpwalk -v2c -c <community> <router> .1.3.6.1.2.1.31.1.1.1.18
IF-MIB::ifAlias.1 = STRING:
IF-MIB::ifAlias.4 = STRING:
IF-MIB::ifAlias.5 = STRING:
IF-MIB::ifAlias.6 = STRING:
IF-MIB::ifAlias.7 = STRING:
IF-MIB::ifAlias.8 = STRING:
IF-MIB::ifAlias.9 = STRING:
IF-MIB::ifAlias.10 = STRING:
<etc>

So the alias in fact is empty, isn't it? In this case, it will be skipped by Cacti. That's desired, not a bug. Or am I misunderstanding?
R.

[Pingreply]

When I do this on the shell, it works:

$ snmpwalk -v2c -c <community> <router> .1.3.6.1.2.1.31.1.1.1.18
IF-MIB::ifAlias.1 = STRING:
IF-MIB::ifAlias.4 = STRING:
IF-MIB::ifAlias.5 = STRING:
IF-MIB::ifAlias.6 = STRING:
IF-MIB::ifAlias.7 = STRING:
IF-MIB::ifAlias.8 = STRING:
IF-MIB::ifAlias.9 = STRING:
IF-MIB::ifAlias.10 = STRING:
<etc>

So the alias in fact is empty, isn't it? In this case, it will be skipped by Cacti. That's desired, not a bug. Or am I misunderstanding?
R.

No, only the first few are empty. Further in the list, the strings are filled with the descriptions.

[gandalf]

Some more info:

- Problem isn't with php memory limit
- When I use SNMP v1, I'm getting the IfAlias-info. With V2 I'm not getting the info

you're getting the ifAlias for other indices even with V2, now?
Cacti should simply provide the results that you're getting via snmpwalk. So in case a single ifAlias is empty, Cacti won't show it. In case the next ifAlias.index is available, it should show up. For some devices, it may help to reduce the max OID to 1
R.

[ceuso]

Hi,
I'm having this exact same problem:

- When I use SNMP v1, I'm getting the IfAlias-info. With V2 I'm not getting the info

-snmpwalk: both give the exact same output
snmpwalk -v2c -c <community> <router> .1.3.6.1.2.1.31.1.1.1.18
snmpwalk -v1 -c <community> <router> .1.3.6.1.2.1.31.1.1.1.18

- only the first few [ifAlias] are empty. Further in the list, the strings are filled with the descriptions.
- cacti verbose query (when in v2):
...
+ Located input field 'ifAlias' [walk]
+ Executing SNMP walk for data @ '.1.3.6.1.2.1.31.1.1.1.18'
+ Located input field 'ifType' [walk]
+ Executing SNMP walk for data @ '.1.3.6.1.2.1.2.2.1.3'
...

Using:
Cacti Version 0.8.8a
Cacti OS unix
SNMP Version NET-SNMP version: 5.3.2.2
RRDTool Version RRDTool 1.4.x

Let me know if you need any more information.

thanks,

[gandalf]

What does the verbose query show when using V1?
R.

[ceuso]

Hi,

regarding the 'ifAlias', this:
//v2
...<snip>...
+ Found item [ifName='so-3/2/0.0'] index: 602 [from value]
+ Found item [ifName='so-3/2/1.0'] index: 603 [from value]
+ Located input field 'ifAlias' [walk]
+ Executing SNMP walk for data @ '.1.3.6.1.2.1.31.1.1.1.18'
+ Located input field 'ifType' [walk]
+ Executing SNMP walk for data @ '.1.3.6.1.2.1.2.2.1.3'
+ Found item [ifType='ethernetCsmacd(6)'] index: 1 [from value]
+ Found item [ifType='mplsTunnel(150)'] index: 4 [from value]

//v1
...<snip>...
+ Found item [ifName='so-3/2/0.0'] index: 602 [from value]
+ Found item [ifName='so-3/2/1.0'] index: 603 [from value]
+ Located input field 'ifAlias' [walk]
+ Executing SNMP walk for data @ '.1.3.6.1.2.1.31.1.1.1.18'
+ Found item [ifAlias=''] index: 1 [from value]
+ Found item [ifAlias=''] index: 4 [from value]
+ Found item [ifAlias=''] index: 5 [from value]

(*) as said before "only the first few [ifAlias] are empty. Further in the list, the strings are filled with the descriptions", for v1.

You should also know that snmpv2 works **sometimes**. I mean, if you keep trying 'reload data query' over and over again, it will eventually bring the correct IF aliases.
Thanks,

[ijimmeh]

Also seeing the same issue with regards to missing ifAlias entries, with the same symptoms as described already.

Only thing I can add to this is that I'm seeing 'SNMP Walk Timeout' in the logs, and have been increasing the timeout value with no luck -

04/19/2013 10:00:27 AM - CMDPHP: Poller[0] WARNING: SNMP Walk Timeout for Host:'<ipaddress>', and OID:'.1.3.6.1.2.1.31.1.1.1.18' (Timeout 3000)
04/19/2013 10:24:43 AM - CMDPHP: Poller[0] WARNING: SNMP Walk Timeout for Host:'<ipaddress>', and OID:'.1.3.6.1.2.1.31.1.1.1.18' (Timeout 4000)
04/19/2013 10:29:23 AM - CMDPHP: Poller[0] WARNING: SNMP Walk Timeout for Host:'<ipaddress>', and OID:'.1.3.6.1.2.1.31.1.1.1.18' (Timeout 6000)

Cacti Version 0.8.8a

Cheers.

[gandalf]

Hi,

regarding the 'ifAlias', this:
//v2
...<snip>...
+ Found item [ifName='so-3/2/0.0'] index: 602 [from value]
+ Found item [ifName='so-3/2/1.0'] index: 603 [from value]
+ Located input field 'ifAlias' [walk]
+ Executing SNMP walk for data @ '.1.3.6.1.2.1.31.1.1.1.18'
+ Located input field 'ifType' [walk]
+ Executing SNMP walk for data @ '.1.3.6.1.2.1.2.2.1.3'
+ Found item [ifType='ethernetCsmacd(6)'] index: 1 [from value]
+ Found item [ifType='mplsTunnel(150)'] index: 4 [from value]

//v1
...<snip>...
+ Found item [ifName='so-3/2/0.0'] index: 602 [from value]
+ Found item [ifName='so-3/2/1.0'] index: 603 [from value]
+ Located input field 'ifAlias' [walk]
+ Executing SNMP walk for data @ '.1.3.6.1.2.1.31.1.1.1.18'
+ Found item [ifAlias=''] index: 1 [from value]
+ Found item [ifAlias=''] index: 4 [from value]
+ Found item [ifAlias=''] index: 5 [from value]

(*) as said before "only the first few [ifAlias] are empty. Further in the list, the strings are filled with the descriptions", for v1.

You should also know that snmpv2 works **sometimes**. I mean, if you keep trying 'reload data query' over and over again, it will eventually bring the correct IF aliases.
Thanks,

In case this is "stable" and providing "correct results" when using SNMP V1, it is very likely that this is an issue with the device's ability to handle snmpbulkwalks.
R.

[ijimmeh]

In case this is "stable" and providing "correct results" when using SNMP V1, it is very likely that this is an issue with the device's ability to handle snmpbulkwalks.
R.

I'm not sure about any one else but from my perspective I don't see it being an issue with the device I'm polling. The tests I'm doing are on a newly built system that is replacing an existing instance, which currently works fine.

Old System:

CentOS 4 (32-bit)
NET-SNMP Version 5.1.2
Cacti Version 0.8.7h

Verbose Query works as expected every time -

+ Located input field 'ifAlias' [walk]
+ Executing SNMP walk for data @ '.1.3.6.1.2.1.31.1.1.1.18'
+ Found item [ifAlias=''] index: 1 [from value]
+ Found item [ifAlias=''] index: 4 [from value]
+ Found item [ifAlias=''] index: 5 [from value]
+ Found item [ifAlias=''] index: 6 [from value]
+ Found item [ifAlias=''] index: 7 [from value]
+ Found item [ifAlias=''] index: 8 [from value]
+ Found item [ifAlias=''] index: 9 [from value]
+ Found item [ifAlias=''] index: 10 [from value]
...etc...


New System:

Centos 6 (64-bit)
NET-SNMP Version 5.5
Cacti Version 0.8.8a

Verbose Query never works -

+ Located input field 'ifAlias' [walk]
+ Executing SNMP walk for data @ '.1.3.6.1.2.1.31.1.1.1.18'
+ Located input field 'ifType' [walk]


Oddly, if I test from command line on the new system using - snmpbulkwalk -v2c -t 0.5 -c <community> <ipaddress> .1.3.6.1.2.1.31.1.1.1.18 - then this works every time.

[ceuso]

...it is very likely that this is an issue with the device's ability to handle snmpbulkwalks

Don't think so. I see this problem in some routers and not in others (routers from the same vendor and the same SW).

[]'s

[speedr6]

I am having the same issue with Juniper SRX. Anyone have a solution to this?