- [Instructor] IP SLA, or IP service level agreements,
are a feature built into Cisco's IOS
that provides a way to monitor network performance.
This is an active method for monitoring and reporting
as it has the ability to report on our traffic
in real time.
Metrics that IP SLA has the ability to report on
include basic connectivity, delay, jitter,
packet loss and sequencing, response time, and much more.
This is a very common tool for service providers
that they use to monitor customer sites,
whether that's internet service providers
or data center providers,
but it can also be helpful to us
as we're troubleshooting our own topologies.
The main benefit of IP SLA is that
it does not require a physical probe
in order to monitor network performance.
It simply uses generated traffic
to measure the performance of a network between devices.
Configuring IP SLA requires an IP SLA source,
and optionally, a IP SLA responder.
The IP SLA source will generate packets
and send those to a destination device
somewhere else on the network.
This can be as simple as an ICMP echo
used to continuously test reachability of a remote device.
The response from the remote device
would have time-stamp information
that would allow the IP SLA source to make calculations
around certain network metrics
that would be of interest to us.
Optionally, a remote Cisco router could be configured
as a IP SLA responder.
This would allow the device to respond to more advanced
IP SLA request packets.
Some IP SLA operations will work without a responder
on the other side.
Some of those operations would include ICMP or HTTP.
In order for IP SLA to be effective,
they leverage SNMP traps triggered by events,
such as connection loss, jitter, latency,
and packet loss just to name a few things.
For any IP SLA metric, certain thresholds can be set.
So for example, we might set a threshold
for a specific round time trip metric.
Any time our IP SLA detected a threshold violation,
that is, if the round trip time went above
our configured upper limit in this example,
an SNMP trap would be sent out to trigger an alert
to an administrator.
Also, threshold violations can be used to trigger
other IP SLA operations for subsequent testing
in the event of a violation.
So for example, the frequency of the probe
may be increased to ensure that the information
is accurate and that it's not just an anomaly.
An additional and optional piece of an IP SLA configuration
is some type of SNMP agent.
That's going to give you the ability to more easily read
and interpret ICLA reporting.
Some of those popular options include
SolarWinds, PRTG, and Nagios Core,
but there are many many SNMP monitoring tools on the market.
These are going to provide a very intuitive reporting method
from a central location,
similar to things we've looked at
in other network management videos.
In our next video, we're going to take a look at
how to configure basic IP SLA to monitor
network connectivity using ICMP echo messages.