Spine didn't support IPv6 only host (hostname with only AAAA record)

[ndeffayet]

With the last version (1.1.38) of Cacti and Spine:

1) cmd.php works fine with IPv6 only host (hostname with only AAAA record) 2) Spine didn't works with IPv6 only host (hostname with only AAAA record)

It's not possible to add anymore udp6: in front of hostname/address as workaround in Cacti because it result of: "Session SNMP error - SNMP::__construct(): php_network_getaddresses: getaddrinfo failed: Name or service not known"

It's critical to have Spine able to poll IPv6 only host.

[netniV]

I think this was already addressed recently. I"ll see if I can find the previous issue that was opened aobut IPv6 as i'm sure this is identical.

[netniV]

This may be related to the library problems we experienced here https://github.com/Cacti/cacti/issues/1634

[ndeffayet]

It can't be related to https://github.com/Cacti/cacti/issues/1634 because:

• Spine is not using PHP (bug 1634 is a bug related to PHP)
• Spine require to have hostname with prefix "udp6:" for IPv6 only hostname
• It's not possible to use anymore the udp6 workaround by setting udp6: in front of hostname value in Cacti because Cacti didn't handle it correctly anymore (remove udp6: for PHP queries but leave udp6: for Spine. There is no code in Cacti to do this.

[netniV]

Actually the udp6: thing was for net-snmp which is used by both cacti and spine. However, as Cacti also uses the same hostname for other calls outside of net-snmp, you are correct it wouldn't work globally.

I'm not saying it's exactly the same bug as 1634, but it is likely to introduced due to changes in the libraries, not that it's the same bug. What OS and library versions are you running? It's probably easier to post the output from the technical support page (feel free to block out any confidential parts).

[netniV]

Also, whilst you say spine doesn't work, you've not actually said why / how it doesn't work? eg, provide logs of the actual issues

[ndeffayet]

Spine didn't work:

• Host have status Down in Management>Devices (host have status Up when using cmd.php)
• Spine report Invalid SNMP session in log: SPINE: Poller[1] Device[109] Hostname[host] ERROR: HOST EVENT: Device is DOWN Message: Invalid SNMP Session

For recall host is IPv6 only.

[netniV]

OK so to try and narrow this down, I have decided to break down the spine code for you under spine 1.1.38 (and I still believe the error comes outside of spine):

The first message you listed in your first post does not even appear. The "Invalid SNMP Session" message appears only once in ping.c under ping_snmp() function. That is called by ping_host() which is again in ping.c and is called from poller.c.

They all rely on the snmp_session pointer on the host object which is built as such:

if (((host->snmp_version >= 1) && (host->snmp_version <= 2) &&
        (strlen(host->snmp_community) > 0)) ||
        (host->snmp_version == 3)) {
        host->snmp_session = snmp_host_init(host->id,
                host->hostname,
                host->snmp_version,
                host->snmp_community,
                host->snmp_username,
                host->snmp_password,
                host->snmp_auth_protocol,
                host->snmp_priv_passphrase,
                host->snmp_priv_protocol,
                host->snmp_context,
                host->snmp_engine_id,
                host->snmp_port,
                host->snmp_timeout);
} else {
        host->snmp_session = NULL;
}

So, either you have not got an SNMP version set (which I doubt) or the snmp_host_init() is failing. snmp_host_init() is in snmp.c and does a lot of work building the various parameters specific for the host into the session object that will be used to open the SNMP connection to the device. The first thing that it does is to call snmp_sess_init() which is an external function and then runs through a load of parameter settings under it gets to the host name:

snprintf(hostnameport, BUFSIZE, "%s:%i", hostname, snmp_port);
session.peername    = hostnameport;

Peername is never set or read from again within the spine code. It's only used by the netsnmp library as part of the session.

$grep "peername" * -R
snmp.c: session.peername    = hostnameport;

I'll check with one of my colleagues, see if he believes one of our recent fixes in the cmd.php code is applicable here (I suspect it is). Then hopefully we can mark the issue as resolved.

[netniV]

In the meantime, could you make sure you are using the same spine / cacti versions.

[ndeffayet]

Many thanks for your feedback. I confim I use the same version of Spine and Cacti (1.1.38).

[netniV]

Looked at the fix for the PHP side of things and that was to use quick_print = true. However, when I just looked to see if I could work out the C code version of this, I couldn't find that as a parameter on the session structure so that has me slightly confused.

[cigamit]

How is the host addressed in the host description in Cacti. Also, what version of Net-SNMP were you compiling against? Does the host have an IPv4 address as well? Can you use the IPv6 address instead of the dns hostname till we have this fixed. I know the issue and just have not had the time to address it.

[TheWitness]

Okay, ping has been updated to issue a warning of a ping_[tcp|udp|icmp] are attempted on an IPv6 host. If that option is selected, the ping will be ignored. If the ping type does not include snmp, an error will be issued.