| Subject: | SNMPv3 Synchronization hangs with some agents and has one unnecessary packet exchange with net-snmp agent |
Hi David,
I want to use Net-SNMP in SNMPv3 AuthPriv mode with the sysedge Client
from CA / Concord and I get the messages:
error: [2514] Net::SNMP::__ANON__(): No response from remote host
'lenny' during synchronization
debug: [2567] Net::SNMP::_discovery_synchronization_cb():
synchronization failed
I get successful answers, if I use snmpget or snmpwalk from net-snmp
with SNMPv3.
Using the net-snmp agent I found the following differences in the
communication between snmpget and Net::SNMP to the agent.
Discovery Phase
1. snmpget and Net::SNMP send an empty SNMPv3 Request
2. net-snmp daemon and sysedge answer with a SNMPv3 Report PDU with the
OID usmStatsUnknownEngineIDs, where in the PDU
msgAuthoritativeEngineID, msgAuthoritativeEngineBoots and
msgAuthoritativeEngineTime are setted
3a. snmpget sends an encrypted SNMPv3 request with the now known values
of the agents
msgAuthoritativeEngineID, msgAuthoritativeEngineBoots and
msgAuthoritativeEngineTime
3b. Net::SNMP sends an encrypted SNMPv3 request with the now known value
of msgAuthoritativeEngineID,
but msgAuthoritativeEngineBoots and msgAuthoritativeEngineTime are 0
4a. net-snmp daemon and sysedge answer to snmpget with the encrypted
SNMPv3 response - communication is successfully
4b-1. net-snmp daemon answers with a new Report PDU
usmStatsNotInTimeWindows and in the next request
Net::SNMP takes over msgAuthoritativeEngineBoots and
msgAuthoritativeEngineTime from the agent
- communication is successfully, but has one unnecessary packet exchange
4b-2. sysedge daemon ignores the message with the unsetted
msgAuthoritativeEngineBoots and msgAuthoritativeEngineTime
- communication times out and fails.
I suggest to implement the same SNMPv3 behaviour like net-snmp snmpget, ...
With the following Patches this behaviour could be reached:
------------------------------------------
Net-SNMP-6.0.0
Show quoted text
> cat USM.pm-6.0.0.patch
--- USM.pm.orig 2009-09-09 17:13:02.000000000 +0200
+++ USM.pm 2010-03-01 09:05:54.000000000 +0100
@@ -454,7 +454,7 @@
} else {
# Handle authoritativeEngineID discovery
- if (!defined $this->_engine_id_discovery($msg_engine_id)) {
+ if (!defined $this->_engine_id_discovery($msg_engine_id,
$msg_engine_boots, $msg_engine_time)) {
return $this->_error();
}
@@ -982,7 +982,10 @@
sub _engine_id_discovery
{
- my ($this, $engine_id) = @_;
+ my $this = shift;
+ my $engine_id = shift;
+ my $msg_engine_boots = shift || 0;
+ my $msg_engine_time = shift || 0;
return TRUE if ($this->{_authoritative});
@@ -1003,6 +1006,10 @@
return $this->_error();
}
+ if (!$this->_synchronize($msg_engine_boots, $msg_engine_time)) {
+ return $this->_error;
+ }
+
return TRUE;
}
------------------------------------------
Net-SNMP-5.2.0
Show quoted text> cat USM.pm-5.2.0.patch
--- USM.pm.orig 2010-03-01 08:24:07.000000000 +0100
+++ USM.pm 2010-03-01 08:45:28.000000000 +0100
@@ -447,7 +447,7 @@
} else {
# Handle authoritativeEngineID discovery
- if (!defined($this->_engine_id_discovery($msg_engine_id))) {
+ if (!defined($this->_engine_id_discovery($msg_engine_id,
$msg_engine_boots, $msg_engine_time))) {
return $this->_error;
}
@@ -985,7 +985,10 @@
sub _engine_id_discovery
{
- my ($this, $engine_id) = @_;
+ my $this = shift;
+ my $engine_id = shift;
+ my $msg_engine_boots = shift || 0;
+ my $msg_engine_time = shift || 0;
return TRUE if ($this->{_authoritative});
@@ -997,6 +1000,9 @@
$this->{_discovered} = FALSE;
return $this->_error;
}
+ if (!$this->_synchronize($msg_engine_boots, $msg_engine_time)) {
+ return $this->_error;
+ }
} else {
return $this->_error(
'Invalid incoming msgAuthoritativeEngineID length [%d octet%s]',
Best Regards
Lars Gloeckner
| Subject: | USM.pm-5.2.0.patch |
--- USM.pm.orig 2010-03-01 08:24:07.000000000 +0100
+++ USM.pm 2010-03-01 08:45:28.000000000 +0100
@@ -447,7 +447,7 @@
} else {
# Handle authoritativeEngineID discovery
- if (!defined($this->_engine_id_discovery($msg_engine_id))) {
+ if (!defined($this->_engine_id_discovery($msg_engine_id, $msg_engine_boots, $msg_engine_time))) {
return $this->_error;
}
@@ -985,7 +985,10 @@
sub _engine_id_discovery
{
- my ($this, $engine_id) = @_;
+ my $this = shift;
+ my $engine_id = shift;
+ my $msg_engine_boots = shift || 0;
+ my $msg_engine_time = shift || 0;
return TRUE if ($this->{_authoritative});
@@ -997,6 +1000,9 @@
$this->{_discovered} = FALSE;
return $this->_error;
}
+ if (!$this->_synchronize($msg_engine_boots, $msg_engine_time)) {
+ return $this->_error;
+ }
} else {
return $this->_error(
'Invalid incoming msgAuthoritativeEngineID length [%d octet%s]',
| Subject: | USM.pm-6.0.0.patch |
--- USM.pm.orig 2009-09-09 17:13:02.000000000 +0200
+++ USM.pm 2010-03-01 09:05:54.000000000 +0100
@@ -454,7 +454,7 @@
} else {
# Handle authoritativeEngineID discovery
- if (!defined $this->_engine_id_discovery($msg_engine_id)) {
+ if (!defined $this->_engine_id_discovery($msg_engine_id, $msg_engine_boots, $msg_engine_time)) {
return $this->_error();
}
@@ -982,7 +982,10 @@
sub _engine_id_discovery
{
- my ($this, $engine_id) = @_;
+ my $this = shift;
+ my $engine_id = shift;
+ my $msg_engine_boots = shift || 0;
+ my $msg_engine_time = shift || 0;
return TRUE if ($this->{_authoritative});
@@ -1003,6 +1006,10 @@
return $this->_error();
}
+ if (!$this->_synchronize($msg_engine_boots, $msg_engine_time)) {
+ return $this->_error;
+ }
+
return TRUE;
}