NAME
Smokeping::probes::CiscoRTTMonEchoICMP - Probe for SmokePing
SYNOPSIS
*** Probes ***
+CiscoRTTMonEchoICMP
forks = 5
offset = 50%
step = 300
timeout = 15
# The following variables can be overridden in each target section
ioshost = RTTcommunity@Myrouter.foobar.com.au # mandatory
iosint = 10.33.22.11
packetsize = 56
pings = 5
tos = 160
vrf = INTERNET
# [...]
*** Targets ***
probe = CiscoRTTMonEchoICMP # if this should be the default probe
# [...]
+ mytarget
# probe = CiscoRTTMonEchoICMP # if the default probe is something else
host = my.host
ioshost = RTTcommunity@Myrouter.foobar.com.au # mandatory
iosint = 10.33.22.11
packetsize = 56
pings = 5
tos = 160
vrf = INTERNET
DESCRIPTION
A probe for smokeping, which uses the ciscoRttMon MIB functionality
("Service Assurance Agent", "SAA") of Cisco IOS to measure ICMP echo
("ping") roundtrip times between a Cisco router and any IP address.
VARIABLES
Supported probe-specific variables:
forks
Run this many concurrent processes at maximum
Example value: 5
Default value: 5
offset
If you run many probes concurrently you may want to prevent them
from hitting your network all at the same time. Using the probe-
specific offset parameter you can change the point in time when
each probe will be run. Offset is specified in % of total interval,
or alternatively as ’random’, and the offset from the ’General’
section is used if nothing is specified here. Note that this does
NOT influence the rrds itself, it is just a matter of when data
acqusition is initiated. (This variable is only applicable if the
variable ’concurrentprobes’ is set in the ’General’ section.)
Example value: 50%
step
Duration of the base interval that this probe should use, if
different from the one specified in the ’Database’ section. Note
that the step in the RRD files is fixed when they are originally
generated, and if you change the step parameter afterwards, you’ll
have to delete the old RRD files or somehow convert them. (This
variable is only applicable if the variable ’concurrentprobes’ is
set in the ’General’ section.)
Example value: 300
timeout
How long a single ’ping’ takes at maximum
Example value: 15
Default value: 5
Supported target-specific variables:
ioshost
The (mandatory) ioshost parameter specifies the Cisco router, which
will execute the pings, as well as the SNMP community string on the
router.
Example value: RTTcommunity@Myrouter.foobar.com.au
This setting is mandatory.
iosint
The (optional) iosint parameter is the source address for the pings
sent. This should be one of the active (!) IP addresses of the
router to get results. IOS looks up the target host address in the
forwarding table and then uses the interface(s) listed there to
send the ping packets. By default IOS uses the (primary) IP address
on the sending interface as source address for a ping. The RTTMon
MIB versions before IOS 12.0(3)T didn’t support this parameter.
Example value: 10.33.22.11
packetsize
The packetsize parameter lets you configure the packetsize for the
pings sent. The minimum is 8, the maximum 16392. Use the same
number as with fping, if you want the same packet sizes being used
on the network.
Default value: 56
pings
How many pings should be sent to each target, if different from the
global value specified in the Database section. Note that the
number of pings in the RRD files is fixed when they are originally
generated, and if you change this parameter afterwards, you’ll have
to delete the old RRD files or somehow convert them.
Example value: 5
tos The (optional) tos parameter specifies the value of the ToS byte in
the IP header of the pings. Multiply DSCP values times 4 and
Precedence values times 32 to calculate the ToS values to
configure, e.g. ToS 160 corresponds to a DSCP value 40 and a
Precedence value of 5. The RTTMon MIB versions before IOS 12.0(3)T
didn’t support this parameter.
Example value: 160
Default value: 0
vrf The the VPN name in which the RTT operation will be used. For
regular RTT operation this field should not be configured. The
agent will use this field to identify the VPN routing Table for
this operation.
Example value: INTERNET
AUTHORS
Joerg.Kummer at Roche.com
NOTES
IOS VERSIONS
It is highly recommended to use this probe with routers running IOS
12.0(3)T or higher and to test it on less critical routers first. I
managed to crash a router with 12.0(9) quite consistently ( in IOS
lingo 12.0(9) is older code than 12.0(3)T ). I did not observe crashes
on higher IOS releases, but messages on the router like the one below,
when multiple processes concurrently accessed the same router (this
case was IOS 12.1(12b) ):
Aug 20 07:30:14: %RTT-3-SemaphoreBadUnlock: %RTR: Attempt to unlock
semaphore by wrong RTR process 70, locked by 78
Aug 20 07:35:15: %RTT-3-SemaphoreInUse: %RTR: Could not obtain a lock
for RTR. Process 80
INSTALLATION
To install this probe copy ciscoRttMonMIB.pm files to
($SMOKEPINGINSTALLDIR)/lib/Smokeping and CiscoRTTMonEchoICMP.pm to
($SMOKEPINGINSTALLDIR)/lib/Smokeping/probes. V0.97 or higher of Simon
Leinen’s SNMP_Session.pm is required.
The router(s) must be configured to allow read/write SNMP access.
Sufficient is:
snmp-server community RTTCommunity RW
If you want to be a bit more restrictive with SNMP write access to the
router, then consider configuring something like this
access-list 2 permit 10.37.3.5
snmp-server view RttMon ciscoRttMonMIB included
snmp-server community RTTCommunity view RttMon RW 2
The above configuration grants SNMP read-write only to 10.37.3.5 (the
smokeping host) and only to the ciscoRttMon MIB tree. The probe does
not need access to SNMP variables outside the RttMon tree.
BUGS
The probe sends unnecessary pings, i.e. more than configured in the
"pings" variable, because the RTTMon MIB only allows to set a total
time for all pings in one measurement run (one "life"). Currently the
probe sets the life duration to "pings"*2+3 seconds (2 secs is the ping
timeout value hardcoded into this probe).
SEE ALSO
<http://oss.oetiker.ch/smokeping/>
<http://www.switch.ch/misc/leinen/snmp/perl/>
The best source for background info on SAA is Cisco’s documentation on
<http://www.cisco.com> and the CISCO-RTTMON-MIB documentation, which is
available at: <ftp://ftp.cisco.com/pub/mibs/v2/CISCO-RTTMON-MIB.my>
2.3.6 doc::Smokeping::probes::CiscoRTTMonEchoICMP(3)