[SNMP Plugin] Use Part of OID as Field Name

[TelcoJordan]

I've run into a situation that I'm not sure can be solved using the snmp plugin. I believe I need to use a substring of a numerical OID as the name for the value obtained by querying that OID.

The component I'm querying is a Cisco 7900 series router for BGP peers prefixes.
Below is the truncated output of an snmp walk command.

$ snmpwalk -v2c -On -c myCommunity <7609 IP addr>:161 .1.3.6.1.4.1.9.9.187.1.2.4.1.1
.1.3.6.1.4.1.9.9.187.1.2.4.1.1.10.232.8.5.1.128 = Counter32: 0
.1.3.6.1.4.1.9.9.187.1.2.4.1.1.10.232.8.10.1.128 = Counter32: 769
.1.3.6.1.4.1.9.9.187.1.2.4.1.1.10.232.8.15.1.128 = Counter32: 175
.1.3.6.1.4.1.9.9.187.1.2.4.1.1.10.233.8.1.1.128 = Counter32: 284
.1.3.6.1.4.1.9.9.187.1.2.4.1.1.10.233.8.5.1.128 = Counter32: 0
.1.3.6.1.4.1.9.9.187.1.2.4.1.1.10.233.8.10.1.128 = Counter32: 256
.1.3.6.1.4.1.9.9.187.1.2.4.1.1.10.233.8.15.1.128 = Counter32: 191

OID .1.3.6.1.4.1.9.9.187.1.2.4.1.1 is called cbgpPeerAcceptedPrefixes in the following MIB: CISCO-BGP4-MIB and has dependencies BGP4-MIB and CISCO-SMI all located at ftp://ftp.cisco.com/pub/mibs/v2

As you can see, the IP address of each BGP peer is contained in the numerical OID. Above, Peer 10.232.8.10 has 769 accepted prefixes. Unfortunately, I can't see a way to have telegraf output this correctly.

Relevant telegraf.conf:

[[inputs.snmp]]
  agents = [ "<7609 IP addr>:161" ]
  version = 2
  timeout = "5s"
  community = "myCommunity"
  tagexclude = ["host","agent_host"]
  max_repetitions = 10
  interval = "60s"
  name = "7609_pe_summary_stats"

[[inputs.snmp.table]]
   name = "bgp_peer_prefix_counts"
   inherit_tags = [ "hostname" ]

   [[inputs.snmp.table.field]]
      oid = "1.3.6.1.4.1.9.9.187.1.2.4.1.1"

Telegraf outputs, depending on whether MIBs are loaded or not:

* Plugin: inputs.snmp, Collection 1
* Internal: 1m0s
> bgp_peer_prefix_counts,hostname=7609_hostname 1.3.6.1.4.1.9.9.187.1.2.4.1.1=175i 1484769545000000000
> bgp_peer_prefix_counts,hostname=7609_hostname 1.3.6.1.4.1.9.9.187.1.2.4.1.1=256i 1484769545000000000
> bgp_peer_prefix_counts,hostname=7609_hostname 1.3.6.1.4.1.9.9.187.1.2.4.1.1=769i 1484769545000000000
> bgp_peer_prefix_counts,hostname=7609_hostname 1.3.6.1.4.1.9.9.187.1.2.4.1.1=284i 1484769545000000000
> bgp_peer_prefix_counts,hostname=7609_hostname 1.3.6.1.4.1.9.9.187.1.2.4.1.1=0i 1484769545000000000
> bgp_peer_prefix_counts,hostname=7609_hostname 1.3.6.1.4.1.9.9.187.1.2.4.1.1=0i 1484769545000000000
> bgp_peer_prefix_counts,hostname=7609_hostname 1.3.6.1.4.1.9.9.187.1.2.4.1.1=191i 1484769545000000000

* Plugin: inputs.snmp, Collection 1
* Internal: 1m0s
> bgp_peer_prefix_counts,hostname=7609_hostname cbgpPeerAcceptedPrefixes=175i 1484769468000000000
> bgp_peer_prefix_counts,hostname=7609_hostname cbgpPeerAcceptedPrefixes=284i 1484769468000000000
> bgp_peer_prefix_counts,hostname=7609_hostname cbgpPeerAcceptedPrefixes=256i 1484769468000000000
> bgp_peer_prefix_counts,hostname=7609_hostname cbgpPeerAcceptedPrefixes=0i 1484769468000000000
> bgp_peer_prefix_counts,hostname=7609_hostname cbgpPeerAcceptedPrefixes=191i 1484769468000000000
> bgp_peer_prefix_counts,hostname=7609_hostname cbgpPeerAcceptedPrefixes=769i 1484769468000000000
> bgp_peer_prefix_counts,hostname=7609_hostname cbgpPeerAcceptedPrefixes=0i 1484769468000000000

The telegraf snmp plugin outputs only the OID prefix without the IP address information. I'm willing to accept the entire OID string if need be but I do need the prefix values to be reported uniquely.

I have looked for ways around this but cannot find the IP addresses as OID values anywhere else within the BGP route table MIBs.

System info:

Telegraf v1.1.1 (git: release-1.1.0 94de9dca1fc6efb3a4bf3ec6869c356278c6755a)
on Fedora 24

Thanks for any assistance you can provide.

[sparrc]

cc @phemmer

[toni-moreno]

I think you will be able to get the entire ip as a tag in snmpcollector. ( we are already getting complete domain names from some dns boxes )

Feel free to test it

https://github.com/toni-moreno/snmpcollector

https://github.com/toni-moreno/snmpcollector/wiki

[phemmer]

Still pondering on this. It's extremely odd that this agent wouldn't provide an OID for the IP.
I think it might not be that hard to add a config flag to provide the table index as a tag.

[phemmer]

Oh, see #1948. I think this might be a duplicate of that.

[krisvoegele]

@phemmer I'm running into this issue as well (polling bgp peering prefixes) but am unable to get the table index as a tag portion working. When I try the suggestions from the related issues I get "Error in plugin: initializing table bgp_peer_prefix_counts: getting table columns: Was that a table?", which I assume is due to using the wrong OID for the "inputs.snmp.table" portion. My current base config that partially works:

[[inputs.snmp.table]]
   name = "bgp_peer_accepted_prefixes"
   inherit_tags = [ "hostname" ]

   [[inputs.snmp.table.field]]
      oid = "1.3.6.1.4.1.9.9.187.1.2.4.1.1"

results in:

> bgp_peer_prefix_counts,agent_host=host1,host=host2 enterprises.9.9.187.1.2.4.1.1=10i 1633630981000000000
> bgp_peer_prefix_counts,agent_host=host1,host=host2 enterprises.9.9.187.1.2.4.1.1=7i 1633630981000000000
> bgp_peer_prefix_counts,agent_host=host1,host=host2 enterprises.9.9.187.1.2.4.1.1=22i 1633630981000000000

when I test the config via CLI, however the localhost/metrics page shows only the first peering. I'm not exactly sure which OID to use to catch the table index. Any help would be greatly appreciated.
Telegraf 1.18.0