| Rfc | 7747 |
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| Title | Basic BGP Convergence Benchmarking Methodology for Data-Plane
Convergence |
|---|
| Author | R. Papneja, B. Parise, S. Hares, D. Lee, I. Varlashkin |
|---|
| Date | April 2016 |
|---|
| Format: | TXT, HTML |
|---|
| Status: | INFORMATIONAL |
|---|
|
Internet Engineering Task Force (IETF) R. Papneja
Request for Comments: 7747 Huawei Technologies
Category: Informational B. Parise
ISSN: 2070-1721 Skyport Systems
S. Hares
Huawei Technologies
D. Lee
IXIA
I. Varlashkin
Google
April 2016
Basic BGP Convergence Benchmarking Methodology
for Data-Plane Convergence
Abstract
BGP is widely deployed and used by several service providers as the
default inter-AS (Autonomous System) routing protocol. It is of
utmost importance to ensure that when a BGP peer or a downstream link
of a BGP peer fails, the alternate paths are rapidly used and routes
via these alternate paths are installed. This document provides the
basic BGP benchmarking methodology using existing BGP convergence
terminology as defined in RFC 4098.
Status of This Memo
This document is not an Internet Standards Track specification; it is
published for informational purposes.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Not all documents
approved by the IESG are a candidate for any level of Internet
Standard; see Section 2 of RFC 5741.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
http://www.rfc-editor.org/info/rfc7747.
Copyright Notice
Copyright (c) 2016 IETF Trust and the persons identified as the
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1. Benchmarking Definitions . . . . . . . . . . . . . . . . 4
1.2. Purpose of BGP FIB (Data-Plane) Convergence . . . . . . . 4
1.3. Control-Plane Convergence . . . . . . . . . . . . . . . . 5
1.4. Benchmarking Testing . . . . . . . . . . . . . . . . . . 5
2. Existing Definitions and Requirements . . . . . . . . . . . . 5
3. Test Topologies . . . . . . . . . . . . . . . . . . . . . . . 6
3.1. General Reference Topologies . . . . . . . . . . . . . . 7
4. Test Considerations . . . . . . . . . . . . . . . . . . . . . 8
4.1. Number of Peers . . . . . . . . . . . . . . . . . . . . . 9
4.2. Number of Routes per Peer . . . . . . . . . . . . . . . . 9
4.3. Policy Processing/Reconfiguration . . . . . . . . . . . . 9
4.4. Configured Parameters (Timers, etc.) . . . . . . . . . . 9
4.5. Interface Types . . . . . . . . . . . . . . . . . . . . . 11
4.6. Measurement Accuracy . . . . . . . . . . . . . . . . . . 11
4.7. Measurement Statistics . . . . . . . . . . . . . . . . . 11
4.8. Authentication . . . . . . . . . . . . . . . . . . . . . 11
4.9. Convergence Events . . . . . . . . . . . . . . . . . . . 12
4.10. High Availability . . . . . . . . . . . . . . . . . . . . 12
5. Test Cases . . . . . . . . . . . . . . . . . . . . . . . . . 12
5.1. Basic Convergence Tests . . . . . . . . . . . . . . . . . 13
5.1.1. RIB-IN Convergence . . . . . . . . . . . . . . . . . 13
5.1.2. RIB-OUT Convergence . . . . . . . . . . . . . . . . . 15
5.1.3. eBGP Convergence . . . . . . . . . . . . . . . . . . 16
5.1.4. iBGP Convergence . . . . . . . . . . . . . . . . . . 16
5.1.5. eBGP Multihop Convergence . . . . . . . . . . . . . . 17
5.2. BGP Failure/Convergence Events . . . . . . . . . . . . . 18
5.2.1. Physical Link Failure on DUT End . . . . . . . . . . 18
5.2.2. Physical Link Failure on Remote/Emulator End . . . . 19
5.2.3. ECMP Link Failure on DUT End . . . . . . . . . . . . 20
5.3. BGP Adjacency Failure (Non-Physical Link Failure) on
Emulator . . . . . . . . . . . . . . . . . . . . . . . . 20
5.4. BGP Hard Reset Test Cases . . . . . . . . . . . . . . . . 21
5.4.1. BGP Non-Recovering Hard Reset Event on DUT . . . . . 21
5.5. BGP Soft Reset . . . . . . . . . . . . . . . . . . . . . 22
5.6. BGP Route Withdrawal Convergence Time . . . . . . . . . . 24
5.7. BGP Path Attribute Change Convergence Time . . . . . . . 26
5.8. BGP Graceful Restart Convergence Time . . . . . . . . . . 27
6. Reporting Format . . . . . . . . . . . . . . . . . . . . . . 29
7. Security Considerations . . . . . . . . . . . . . . . . . . . 32
8. References . . . . . . . . . . . . . . . . . . . . . . . . . 32
8.1. Normative References . . . . . . . . . . . . . . . . . . 32
8.2. Informative References . . . . . . . . . . . . . . . . . 33
Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 34
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 35
1. Introduction
This document defines the methodology for benchmarking data-plane
Forwarding Information Base (FIB) convergence performance of BGP in
routers and switches using topologies of three or four nodes. The
methodology proposed in this document applies to both IPv4 and IPv6,
and if a particular test is unique to one version, it is marked
accordingly. For IPv6 benchmarking, the Device Under Test (DUT) will
require the support of Multiprotocol BGP (MP-BGP) [RFC4760]
[RFC2545]. Similarly, both Internal BGP (iBGP) and External BGP
(eBGP) are covered in the tests as applicable.
The scope of this document is to provide methodology for BGP FIB
convergence measurements with BGP functionality limited to IPv4 and
IPv6 as defined in [RFC4271] and MP-BGP [RFC4760] [RFC2545]. Other
BGP extensions to support Layer 2 and Layer 3 Virtual Private
Networks (VPNs) are outside the scope of this document. Interaction
with IGPs (IGP interworking) is outside the scope of this document.
1.1. Benchmarking Definitions
The terminology used in this document is defined in [RFC4098]. One
additional term is defined in this document as follows.
FIB (data-plane) convergence is defined as the completion of all FIB
changes so that all forwarded traffic then takes the newly proposed
route. RFC 4098 defines the terms 'BGP device', 'FIB', and
'forwarded traffic'. Data-plane convergence is different than
control-plane convergence within a node.
This document defines methodology to test
o data-plane convergence on a single BGP device that supports the
BGP functionality with a scope as outlined above; and
o using test topology of three or four nodes that are sufficient to
recreate the convergence events used in the various tests of this
document.
1.2. Purpose of BGP FIB (Data-Plane) Convergence
In the current Internet architecture, the inter-AS transit is
primarily available through BGP. To maintain reliable connectivity
within intra-domains or across inter-domains, fast recovery from
failures remains most critical. To ensure minimal traffic losses,
many service providers are requiring BGP implementations to converge
the entire Internet routing table within sub-seconds at FIB level.
Furthermore, to compare these numbers amongst various devices,
service providers are also looking at ways to standardize the
convergence measurement methods. This document offers test methods
for simple topologies. These simple tests will provide a quick high-
level check of BGP data-plane convergence across multiple
implementations from different vendors.
1.3. Control-Plane Convergence
The convergence of BGP occurs at two levels: Routing Information Base
(RIB) and FIB convergence. RFC 4098 defines terms for BGP control-
plane convergence. Methodologies that test control-plane convergence
are out of scope for this document.
1.4. Benchmarking Testing
In order to ensure that the results obtained in tests are repeatable,
careful setup of initial conditions and exact steps are required.
This document proposes these initial conditions, test steps, and
result checking. To ensure uniformity of the results, all optional
parameters SHOULD be disabled and all settings SHOULD be changed to
default; these may include BGP timers as well.
2. Existing Definitions and Requirements
"Benchmarking Terminology for Network Interconnect Devices" [RFC1242]
and "Benchmarking Terminology for LAN Switching Devices" [RFC2285]
SHOULD be reviewed in conjunction with this document. WLAN-specific
terms and definitions are also provided in Clauses 3 and 4 of the
IEEE 802.11 standard [IEEE.802.11]. Commonly used terms may also be
found in RFC 1983 [RFC1983].
For the sake of clarity and continuity, this document adopts the
general template for benchmarking terminology set out in Section 2 of
[RFC1242]. Definitions are organized in alphabetical order and
grouped into sections for ease of reference. The following terms are
assumed to be taken as defined in RFC 1242 [RFC1242]: Throughput,
Latency, Constant Load, Frame Loss Rate, and Overhead Behavior. In
addition, the following terms are taken as defined in [RFC2285]:
Forwarding Rates, Maximum Forwarding Rate, Loads, Device Under Test
(DUT), and System Under Test (SUT).
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119].
3. Test Topologies
This section describes the test setups for use in BGP benchmarking
tests measuring convergence of the FIB (data-plane) after BGP updates
have been received.
These test setups have three or four nodes with the following
configuration:
1. Basic test setup
2. Three-node setup for iBGP or eBGP convergence
3. Setup for eBGP multihop test Scenario
4. Four-node setup for iBGP or eBGP convergence
Individual tests refer to these topologies.
Figures 1 through 4 use the following conventions:
o AS-X: Autonomous System X
o Loopback Int: Loopback interface on a BGP-enabled device
o HLP, HLP1, HLP2: Helper routers running the same version of BGP as
the DUT
o All devices MUST be synchronized using NTP or some other clock
synchronization mechanism
3.1. General Reference Topologies
Emulator acts as one or more BGP peers for different test cases.
+----------+ +------------+
| | Traffic Interfaces | |
| |-----------------------1---- | tx |
| |-----------------------2---- | tr1 |
| |-----------------------3-----| tr2 |
| DUT | | Emulator |
| | Routing Interfaces | |
| Dp1 |--------------------------- |Emp1 |
| | BGP Peering | |
| Dp2 |---------------------------- |Emp2 |
| | BGP Peering | |
+----------+ +------------+
Figure 1: Basic Test Setup
+------------+ +-----------+ +-----------+
| | | | | |
| | | | | |
| HLP | | DUT | | Emulator |
| (AS-X) |--------| (AS-Y) |-----------| (AS-Z) |
| | | | | |
| | | | | |
| | | | | |
+------------+ +-----------+ +-----------+
| |
| |
+--------------------------------------------+
Figure 2: Three-Node Setup for eBGP and iBGP Convergence
+----------------------------------------------+
| |
| |
+------------+ +-----------+ +-----------+
| | | | | |
| | | | | |
| HLP | | DUT | | Emulator |
| (AS-X) |--------| (AS-Y) |-----------| (AS-Z) |
| | | | | |
| | | | | |
| | | | | |
+------------+ +-----------+ +-----------+
|Loopback-Int |Loopback-Int
| |
+ +
Figure 3: BGP Convergence for eBGP Multihop Scenario
+---------+ +--------+ +--------+ +---------+
| | | | | | | |
| | | | | | | |
| HLP1 | | DUT | | HLP2 | |Emulator |
| (AS-X) |-----| (AS-X) |-----| (AS-Y) |-----| (AS-Z) |
| | | | | | | |
| | | | | | | |
| | | | | | | |
+---------+ +--------+ +--------+ +---------+
| |
| |
+---------------------------------------------+
Figure 4: Four-Node Setup for eBGP and iBGP Convergence
4. Test Considerations
The test cases for measuring convergence for iBGP and eBGP are
different. Both iBGP and eBGP use different mechanisms to advertise,
install, and learn the routes. Typically, an iBGP route on the DUT
is installed and exported when the next hop is valid. For eBGP, the
route is installed on the DUT with the remote interface address as
the next hop, with the exception of the multihop test case (as
specified in the test).
4.1. Number of Peers
"Number of Peers" is defined as the number of BGP neighbors or
sessions the DUT has at the beginning of the test. The peers are
established before the tests begin. The relationship could be either
iBGP or eBGP peering depending upon the test case requirement.
The DUT establishes one or more BGP peer sessions with one or more
emulated routers or Helper Nodes. Additional peers can be added
based on the testing requirements. The number of peers enabled
during the testing should be well documented in the report matrix.
4.2. Number of Routes per Peer
"Number of Routes per Peer" is defined as the number of routes
advertised or learned by the DUT per session or through a neighbor
relationship with an emulator or Helper Node. The Tester, emulating
as a BGP neighbor, MUST advertise at least one route per BGP peer.
Each test run must identify the route stream in terms of route
packing, route mixture, and number of routes. This route stream must
be well documented in the reporting stream. RFC 4098 defines these
terms.
It is RECOMMENDED that the user consider advertising the entire
current Internet routing table per peering session using an Internet
route mixture with unique or non-unique routes. If multiple peers
are used, it is important to precisely document the timing sequence
between the peer sending routes (as defined in RFC 4098).
4.3. Policy Processing/Reconfiguration
The DUT MUST run one baseline test where policy is the Minimal policy
as defined in RFC 4098. Additional runs may be done with the policy
that was set up before the tests began. Exact policy settings MUST
be documented as part of the test.
4.4. Configured Parameters (Timers, etc.)
There are configured parameters and timers that may impact the
measured BGP convergence times.
The benchmark metrics MAY be measured at any fixed values for these
configured parameters.
It is RECOMMENDED these configure parameters have the following
settings: a) default values specified by the respective RFC, b)
platform-specific default parameters, and c) values as expected in
the operational network. All optional BGP settings MUST be kept
consistent across iterations of any specific tests
Examples of the configured parameters that may impact measured BGP
convergence time include, but are not limited to:
1. Interface failure detection timer
2. BGP keepalive timer
3. BGP holdtime
4. BGP update delay timer
5. ConnectRetry timer
6. TCP segment size
7. Minimum Route Advertisement Interval (MRAI)
8. MinASOriginationInterval (MAOI)
9. Route flap damping parameters
10. TCP Authentication Option (TCP AO or TCP MD5)
11. Maximum TCP window size
12. MTU
The basic-test settings for the parameters should be:
1. Interface failure detection timer (0 ms)
2. BGP keepalive timer (1 min)
3. BGP holdtime (3 min)
4. BGP update delay timer (0 s)
5. ConnectRetry timer (1 s)
6. TCP segment size (4096 bytes)
7. Minimum Route Advertisement Interval (MRAI) (0 s)
8. MinASOriginationInterval (MAOI) (0 s)
9. Route flap damping parameters (off)
10. TCP Authentication Option (off)
4.5. Interface Types
The type of media dictates which test cases may be executed; each
interface type has a unique mechanism for detecting link failures,
and the speed at which that mechanism operates will influence the
measurement results. All interfaces MUST be of the same media and
throughput for all iterations of each test case.
4.6. Measurement Accuracy
Since observed packet loss is used to measure the route convergence
time, the time between two successive packets offered to each
individual route is the highest possible accuracy of any packet-loss-
based measurement. When packet jitter is much less than the
convergence time, it is a negligible source of error, and hence, it
will be treated as within tolerance.
Other options to measure convergence are the Time-Based Loss Method
(TBLM) and Timestamp-Based Method (TBM) [RFC6414].
An exterior measurement on the input media (such as Ethernet) is
defined by this specification.
4.7. Measurement Statistics
The benchmark measurements may vary for each trial due to the
statistical nature of timer expirations, CPU scheduling, etc. It is
recommended to repeat the test multiple times. Evaluation of the
test data must be done with an understanding of generally accepted
testing practices regarding repeatability, variance, and statistical
significance of a small number of trials.
For any repeated tests that are averaged to remove variance, all
parameters MUST remain the same.
4.8. Authentication
Authentication in BGP is done using the TCP Authentication Option
[RFC5925]. (In some legacy situations, the authentication may still
be with TCP MD5). The processing of the authentication hash,
particularly in devices with a large number of BGP peers and a large
amount of update traffic, can have an impact on the control plane of
the device. If authentication is enabled, it MUST be documented
correctly in the reporting format.
Also, it is recommended that trials MUST be with the same Secure
Inter-Domain Routing (SIDR) features [RFC7115] [BGPsec]. The best
convergence tests would be with no SIDR features and then to repeat
the convergence tests with the same SIDR features.
4.9. Convergence Events
Convergence events or triggers are defined as abnormal occurrences in
the network, which initiate route flapping in the network and hence
forces the reconvergence of a steady state network. In a real
network, a series of convergence events may cause convergence latency
operators desire to test.
These convergence events must be defined in terms of the sequences
defined in RFC 4098. This basic document begins all tests with a
router initial setup. Additional documents will define BGP data-
plane convergence based on peer initialization.
The convergence events may or may not be tied to the actual failure.
A soft reset [RFC4098] does not clear the RIB or FIB tables. A hard
reset clears BGP peer sessions, RIB tables, and FIB tables.
4.10. High Availability
Due to the different Non-Stop-Routing (sometimes referred to High-
Availability) solutions available from different vendors, it is
RECOMMENDED that any redundancy available in the routing processors
should be disabled during the convergence measurements. For cases
where the redundancy cannot be disabled, the results are no longer
comparable and the level of impact on the measurements is out of
scope of this document.
5. Test Cases
All tests defined under this section assume the following:
a. BGP peers are in Established state.
b. BGP state should be cleared from Established state to Idle prior
to each test. This is recommended to ensure that all tests start
with BGP peers being forced back to Idle state and databases
flushed.
c. Furthermore, the traffic generation and routing should be
verified in the topology to ensure there is no packet loss
observed on any advertised routes.
d. The arrival timestamp of advertised routes can be measured by
installing an inline monitoring device between the emulator and
the DUT or by using the span port of the DUT connected with an
external analyzer. The time base of such an inline monitor or
external analyzer needs to be synchronized with the protocol and
traffic emulator. Some modern emulators may have the capability
to capture and timestamp every NLRI packet leaving and arriving
at the emulator ports. The timestamps of these NLRI packets will
be almost identical to the arrival time at the DUT if the cable
distance between the emulator and DUT is relatively short.
5.1. Basic Convergence Tests
These test cases measure characteristics of a BGP implementation in
non-failure scenarios like:
1. RIB-IN Convergence
2. RIB-OUT Convergence
3. eBGP Convergence
4. iBGP Convergence
5.1.1. RIB-IN Convergence
Objective:
This test measures the convergence time taken to receive and
install a route in RIB using BGP.
Reference Test Setup:
This test uses the setup as shown in Figure 1
Procedure:
A. All variables affecting convergence should be set to a basic test
state (as defined in Section 4.4).
B. Establish BGP adjacency between the DUT and one peer of the
emulator, Emp1.
C. To ensure adjacency establishment, wait for three keepalives to
be received from the DUT or a configurable delay before
proceeding with the rest of the test.
D. Start the traffic from the emulator tx towards the DUT targeted
at a route specified in the route mixture (e.g., routeA).
Initially, no traffic SHOULD be observed on the egress interface
as routeA is not installed in the forwarding database of the DUT.
E. Advertise routeA from the peer (Emp1) to the DUT and record the
time.
This is Tup(Emp1,Rt-A), also named XMT-Rt-time(Rt-A).
F. Record the time when routeA from Emp1 is received at the DUT.
This is Tup(DUT,Rt-A), also named RCV-Rt-time(Rt-A).
G. Record the time when the traffic targeted towards routeA is
received by the emulator on the appropriate traffic egress
interface.
This is TR(TDr,Rt-A), also named DUT-XMT-Data-Time(Rt-A).
H. The difference between the Tup(DUT,RT-A) and traffic received
time (TR (TDr, Rt-A) is the FIB convergence time for routeA in
the route mixture. A full convergence for the route update is
the measurement between the first route (Rt-A) and the last route
(Rt-last).
Route update convergence is
TR(TDr, Rt-last)- Tup(DUT, Rt-A), or
(DUT-XMT-Data-Time - RCV-Rt-Time)(Rt-A).
Note: It is recommended that a single test with the same route
mixture be repeated several times. A report should provide the
standard deviation and the average of all tests.
Running tests with a varying number of routes and route mixtures is
important to get a full characterization of a single peer.
5.1.2. RIB-OUT Convergence
Objective:
This test measures the convergence time taken by an implementation
to receive, install, and advertise a route using BGP.
Reference Test Setup:
This test uses the setup as shown in Figure 2.
Procedure:
A. The Helper Node (HLP) MUST run same version of BGP as the DUT.
B. All devices MUST be synchronized using NTP or some local
reference clock.
C. All configuration variables for the Helper Node, DUT, and
emulator SHOULD be set to the same values. These values MAY be
basic test or a unique set completely described in the test
setup.
D. Establish BGP adjacency between the DUT and the emulator.
E. Establish BGP adjacency between the DUT and the Helper Node.
F. To ensure adjacency establishment, wait for three keepalives to
be received from the DUT or a configurable delay before
proceeding with the rest of the test.
G. Start the traffic from the emulator towards the Helper Node
targeted at a specific route (e.g., routeA). Initially, no
traffic SHOULD be observed on the egress interface as routeA is
not installed in the forwarding database of the DUT.
H. Advertise routeA from the emulator to the DUT and note the time.
This is Tup(EMx, Rt-A), also named EM-XMT-Data-Time(Rt-A).
I. Record when routeA is received by the DUT.
This is Tup(DUTr, Rt-A), also named DUT-RCV-Rt-Time(Rt-A).
J. Record the time when routeA is forwarded by the DUT towards the
Helper Node.
This is Tup(DUTx, Rt-A), also named DUT-XMT-Rt-Time(Rt-A).
K. Record the time when the traffic targeted towards routeA is
received on the Route Egress Interface. This is TR(EMr, Rt-A),
also named DUT-XMT-Data Time(Rt-A).
FIB convergence = (DUT-XMT-Data-Time -DUT-RCV-Rt-Time)(Rt-A)
RIB convergence = (DUT-XMT-Rt-Time - DUT-RCV-Rt-Time)(Rt-A)
Convergence for a route stream is characterized by
a) individual route convergence for FIB and RIB, and
b) all route convergence of
FIB-convergence = DUT-XMT-Data-Time(last) - DUT-RCV-Rt-
Time(first), and
RIB-convergence = DUT-XMT-Rt-Time(last) - DUT-RCV-Rt-
Time(first).
5.1.3. eBGP Convergence
Objective:
This test measures the convergence time taken by an implementation
to receive, install, and advertise a route in an eBGP Scenario.
Reference Test Setup:
This test uses the setup as shown in Figure 2, and the scenarios
described in RIB-IN and RIB-OUT are applicable to this test case.
5.1.4. iBGP Convergence
Objective:
This test measures the convergence time taken by an implementation
to receive, install, and advertise a route in an iBGP Scenario.
Reference Test Setup:
This test uses the setup as shown in Figure 2, and the scenarios
described in RIB-IN and RIB-OUT are applicable to this test case.
5.1.5. eBGP Multihop Convergence
Objective:
This test measures the convergence time taken by an implementation
to receive, install, and advertise a route in an eBGP Multihop
Scenario.
Reference Test Setup:
This test uses the setup as shown in Figure 3. The DUT is used
along with a Helper Node.
Procedure:
A. The Helper Node MUST run the same version of BGP as the DUT.
B. All devices MUST be synchronized using NTP or some local
reference clock.
C. All variables affecting convergence, like authentication,
policies, and timers, SHOULD be set to basic settings.
D. All three devices, the DUT, emulator, and Helper Node, are
configured with different ASs.
E. Loopback interfaces are configured on the DUT and Helper Node,
and connectivity is established between them using any config
options available on the DUT.
F. Establish BGP adjacency between the DUT and the emulator.
G. Establish BGP adjacency between the DUT and the Helper Node.
H. To ensure adjacency establishment, wait for three keepalives to
be received from the DUT or a configurable delay before
proceeding with the rest of the test
I. Start the traffic from the emulator towards the DUT targeted at a
specific route (e.g., routeA).
J. Initially, no traffic SHOULD be observed on the egress interface
as routeA is not installed in the forwarding database of the DUT.
K. Advertise routeA from the emulator to the DUT and note the time
(Tup(EMx,RouteA), also named Route-Tx-time(Rt-A).
L. Record the time when the route is received by the DUT. This is
Tup(EMr,DUT), also named Route-Rcv-time(Rt-A).
M. Record the time when the traffic targeted towards routeA is
received from the egress interface of the DUT on the emulator.
This is Tup(EMd,DUT) named Data-Rcv-time(Rt-A)
N. Record the time when routeA is forwarded by the DUT towards the
Helper Node. This is Tup(EMf,DUT), also named Route-Fwd-time(Rt-
A).
FIB Convergence = (Data-Rcv-time - Route-Rcv-time)(Rt-A)
RIB Convergence = (Route-Fwd-time - Route-Rcv-time)(Rt-A)
Note: It is recommended that the test be repeated with a varying
number of routes and route mixtures. With each set route mixture,
the test should be repeated multiple times. The results should
record the average, mean, standard deviation.
5.2. BGP Failure/Convergence Events
5.2.1. Physical Link Failure on DUT End
Objective:
This test measures the route convergence time due to a local link
failure event at the DUT's Local Interface.
Reference Test Setup:
This test uses the setup as shown in Figure 1. The shutdown event
is defined as an administrative shutdown event on the DUT.
Procedure:
A. All variables affecting convergence, like authentication,
policies, and timers, should be set to basic-test policy.
B. Establish two BGP adjacencies from the DUT to the emulator, one
over the peer interface and the other using a second peer
interface.
C. Advertise the same route, routeA, over both adjacencies with
preferences so that the Best Egress Interface for the preferred
next hop is (Emp1) interface.
D. To ensure adjacency establishment, wait for three keepalives to
be received from the DUT or a configurable delay before
proceeding with the rest of the test.
E. Start the traffic from the emulator towards the DUT targeted at a
specific route (e.g., routeA). Initially, traffic would be
observed on the best egress route, Emp1, instead of Emp2.
F. Trigger the shutdown event of Best Egress Interface on the DUT
(Dp1). This time is called Shutdown time.
G. Measure the convergence time for the event to be detected and
traffic to be forwarded to Next-Best Egress Interface (Dp2).
Time = Data-detect(Emp2) - Shutdown time
H. Stop the offered load and wait for the queues to drain. Restart
the data flow.
I. Bring up the link on the DUT's Best Egress Interface.
J. Measure the convergence time taken for the traffic to be rerouted
from Dp2 to Best Egress Interface, Dp1.
Time = Data-detect(Emp1) - Bring Up time
K. It is recommended that the test be repeated with a varying number
of routes and route mixtures or with a number of routes and route
mixtures closer to what is deployed in operational networks.
5.2.2. Physical Link Failure on Remote/Emulator End
Objective:
This test measures the route convergence time due to a local link
failure event at the Tester's Local Interface.
Reference Test Setup:
This test uses the setup as shown in Figure 1. The shutdown event
is defined as a shutdown of the local interface of the Tester via
a logical shutdown event. The procedure used in Section 5.2.1 is
used for the termination.
5.2.3. ECMP Link Failure on DUT End
Objective:
This test measures the route convergence time due to a local link
failure event at the ECMP member. The FIB configuration and BGP
are set to allow two ECMP routes to be installed. However, policy
directs the routes to be sent only over one of the paths.
Reference Test Setup:
This test uses the setup as shown in Figure 1, and the procedure
used in Section 5.2.1.
5.3. BGP Adjacency Failure (Non-Physical Link Failure) on Emulator
Objective:
This test measures the route convergence time due to BGP Adjacency
Failure on the emulator.
Reference Test Setup:
This test uses the setup as shown in Figure 1.
Procedure:
A. All variables affecting convergence, like authentication,
policies, and timers, should be set to basic-policy.
B. Establish two BGP adjacencies from the DUT to the emulator: one
over the Best Egress Interface and the other using the Next-Best
Egress Interface.
C. Advertise the same route, routeA, over both adjacencies with
preferences so that the Best Egress Interface for the preferred
next hop is (Emp1) interface.
D. To ensure adjacency establishment, wait for three keepalives to
be received from the DUT or a configurable delay before
proceeding with the rest of the test.
E. Start the traffic from the emulator towards the DUT targeted at a
specific route (e.g., routeA). Initially, traffic would be
observed on the Best Egress Interface.
F. Remove BGP adjacency via a software adjacency down on the
emulator on the Best Egress Interface. This time is called
BGPadj-down-time, also termed BGPpeer-down.
G. Measure the convergence time for the event to be detected and
traffic to be forwarded to Next-Best Egress Interface. This time
is Tr-rr2, also called TR2-traffic-on.
Convergence = TR2-traffic-on - BGPpeer-down
H. Stop the offered load and wait for the queues to drain and
restart the data flow.
I. Bring up BGP adjacency on the emulator over the Best Egress
Interface. This time is BGP-adj-up, also called BGPpeer-up.
J. Measure the convergence time taken for the traffic to be rerouted
to the Best Egress Interface. This time is Tr-rr1, also called
TR1-traffic-on.
Convergence = TR1-traffic-on - BGPpeer-up
5.4. BGP Hard Reset Test Cases
5.4.1. BGP Non-Recovering Hard Reset Event on DUT
Objective:
This test measures the route convergence time due to a hard reset
on the DUT.
Reference Test Setup:
This test uses the setup as shown in Figure 1.
Procedure:
A. The requirement for this test case is that the hard reset event
should be non-recovering and should affect only the adjacency
between the DUT and the emulator on the Best Egress Interface.
B. All variables affecting the test SHOULD be set to basic-test
values.
C. Establish two BGP adjacencies from the DUT to the emulator: one
over the Best Egress Interface and the other using the Next-Best
Egress Interface.
D. Advertise the same route, routeA, over both adjacencies with
preferences so that the Best Egress Interface for the preferred
next hop is (Emp1) interface.
E. To ensure adjacency establishment, wait for three keepalives to
be received from the DUT or a configurable delay before
proceeding with the rest of the test.
F. Start the traffic from the emulator towards the DUT targeted at a
specific route (e.g., routeA). Initially, traffic would be
observed on the Best Egress Interface.
G. Trigger the hard reset event of the Best Egress Interface on the
DUT. This time is called time reset.
H. This event is detected and traffic is forwarded to the Next-Best
Egress Interface. This time is called time-traffic flow.
I. Measure the convergence time for the event to be detected and
traffic to be forwarded to Next-Best Egress Interface.
Time of convergence = time-traffic flow - time-reset
J. Stop the offered load and wait for the queues to drain and
restart.
K. It is recommended that the test be repeated with a varying number
of routes and route mixtures or with a number of routes and route
mixtures closer to what is deployed in operational networks.
L. When varying number of routes are used, convergence time is
measured using the Loss-Derived method [RFC6412].
M. Convergence time in this scenario is influenced by failure
detection time on the Tester, BGP keepalive time and routing, and
forwarding table update time.
5.5. BGP Soft Reset
Objective:
This test measures the route convergence time taken by an
implementation to service a BGP Route Refresh message and
advertise a route.
Reference Test Setup:
This test uses the setup as shown in Figure 2.
Procedure:
A. The BGP implementation on the DUT and Helper Node needs to
support BGP Route Refresh Capability [RFC2918].
B. All devices MUST be synchronized using NTP or some local
reference clock.
C. All variables affecting convergence, like authentication,
policies, and timers, should be set to basic-test defaults.
D. The DUT and the Helper Node are configured in the same AS,
whereas the emulator is configured under a different AS.
E. Establish BGP adjacency between the DUT and the emulator.
F. Establish BGP adjacency between the DUT and the Helper Node.
G. To ensure adjacency establishment, wait for three keepalives to
be received from the DUT or a configurable delay before
proceeding with the rest of the test.
H. Configure a policy under the BGP on the Helper Node to deny
routes received from the DUT.
I. Advertise routeA from the emulator to the DUT.
J. The DUT will try to advertise the route to the Helper Node; it
will be denied.
K. Wait for three keepalives.
L. Start the traffic from the emulator towards the Helper Node
targeted at a specific route, say routeA. Initially, no traffic
would be observed on the egress interface, as routeA is not
present.
M. Remove the policy on the Helper Node and issue a route refresh
request towards the DUT. Note the timestamp of this event. This
is the RefreshTime.
N. Record the time when the traffic targeted towards routeA is
received on the egress interface. This is RecTime.
O. The following equation represents the Route Refresh Convergence
Time per route.
Route Refresh Convergence Time = (RecTime - RefreshTime)
5.6. BGP Route Withdrawal Convergence Time
Objective:
This test measures the route convergence time taken by an
implementation to service a BGP withdraw message and advertise the
withdraw.
Reference Test Setup:
This test uses the setup as shown in Figure 2.
Procedure:
A. This test consists of two steps to determine the Total Withdraw
Processing Time.
B. Step 1:
(1) All devices MUST be synchronized using NTP or some local
reference clock.
(2) All variables should be set to basic-test parameters.
(3) The DUT and Helper Node are configured in the same AS,
whereas the emulator is configured under a different AS.
(4) Establish BGP adjacency between the DUT and the emulator.
(5) To ensure adjacency establishment, wait for three
keepalives to be received from the DUT or a configurable
delay before proceeding with the rest of the test.
(6) Start the traffic from the emulator towards the DUT
targeted at a specific route (e.g., routeA). Initially, no
traffic would be observed on the egress interface as routeA
is not present on the DUT.
(7) Advertise routeA from the emulator to the DUT.
(8) The traffic targeted towards routeA is received on the
egress interface.
(9) Now the Tester sends a request to withdraw routeA to the
DUT. TRx(Awith) is also called WdrawTime1(Rt-A).
(10) Record the time when no traffic is observed as determined
by the emulator. This is the RouteRemoveTime1(Rt-A).
(11) The difference between the RouteRemoveTime1 and WdrawTime1
is the WdrawConvTime1.
WdrawConvTime1(Rt-A) = RouteRemoveTime1(Rt-A) -
WdrawTime1(Rt-A)
C. Step 2:
(1) Continuing from Step 1, re-advertise routeA back to the DUT
from the Tester.
(2) The DUT will try to advertise routeA to the Helper Node
(this assumes there exists a session between the DUT and
Helper Node).
(3) Start the traffic from the emulator towards the Helper Node
targeted at a specific route (e.g., routeA). Traffic would
be observed on the egress interface after routeA is received
by the Helper Node.
WATime=time traffic first flows
(4) Now the Tester sends a request to withdraw routeA to DUT.
This is the WdrawTime2(Rt-A).
WAWtime-TRx(Rt-A) = WdrawTime2(Rt-A)
(5) DUT processes the withdraw and sends it to the Helper Node.
(6) Record the time when no traffic is observed as determined by
the emulator. This is:
TR-WAW(DUT,RouteA) = RouteRemoveTime2(Rt-A)
(7) Total Withdraw Processing Time is:
TotalWdrawTime(Rt-A) = ((RouteRemoveTime2(Rt-A) -
WdrawTime2(Rt-A)) - WdrawConvTime1(Rt-A))
5.7. BGP Path Attribute Change Convergence Time
Objective:
This test measures the convergence time taken by an implementation
to service a BGP Path Attribute Change.
Reference Test Setup:
This test uses the setup as shown in Figure 1.
Procedure:
A. This test only applies to Well-Known Mandatory Attributes like
origin, AS path, and next hop.
B. In each iteration of the test, only one of these mandatory
attributes need to be varied whereas the others remain the same.
C. All devices MUST be synchronized using NTP or some local
reference clock.
D. All variables should be set to basic-test parameters.
E. Advertise the same route, routeA, over both adjacencies with
preferences so that the Best Egress Interface for the preferred
next hop is (Emp1) interface.
F. To ensure adjacency establishment, wait for three keepalives to
be received from the DUT or a configurable delay before
proceeding with the rest of the test.
G. Start the traffic from the emulator towards the DUT targeted at
the specific route (e.g., routeA). Initially, traffic would be
observed on the Best Egress Interface.
H. Now advertise the same route, routeA, on the Next-Best Egress
Interface but by varying one of the well-known mandatory
attributes to have a preferred value over that interface. We
call this Tbetter. The other values need to be the same as what
was advertised on the Best-Egress adjacency.
TRx(Path-Change(Rt-A)) = Path Change Event Time(Rt-A)
I. Measure the convergence time for the event to be detected and
traffic to be forwarded to Next-Best Egress Interface.
DUT(Path-Change, Rt-A) = Path-switch time(Rt-A)
Convergence = Path-switch time(Rt-A) - Path Change Event
Time(Rt-A)
J. Stop the offered load and wait for the queues to drain and
restart.
K. Repeat the test for various attributes.
5.8. BGP Graceful Restart Convergence Time
Objective:
This test measures the route convergence time taken by an
implementation during a Graceful Restart Event as detailed in the
terminology document [RFC4098].
Reference Test Setup:
This test uses the setup as shown in Figure 4.
Procedure:
A. It measures the time taken by an implementation to service a BGP
Graceful Restart Event and advertise a route.
B. The Helper Nodes are the same model as the DUT and run the same
BGP implementation as the DUT.
C. The BGP implementation on the DUT and Helper Node needs to
support the BGP Graceful Restart Mechanism [RFC4724].
D. All devices MUST be synchronized using NTP or some local
reference clock.
E. All variables are set to basic-test values.
F. The DUT and Helper Node 1 (HLP1) are configured in the same AS,
whereas the emulator and Helper Node 2 (HLP2) are configured
under different ASs.
G. Establish BGP adjacency between the DUT and Helper Nodes.
H. Establish BGP adjacency between the Helper Node 2 and the
emulator.
I. To ensure adjacency establishment, wait for three keepalives to
be received from the DUT or a configurable delay before
proceeding with the rest of the test.
J. Configure a policy under the BGP on Helper Node 1 to deny routes
received from the DUT.
K. Advertise routeA from the emulator to Helper Node 2.
L. Helper Node 2 advertises the route to the DUT and the DUT will
try to advertise the route to Helper Node 1, which will be
denied.
M. Wait for three keepalives.
N. Start the traffic from the emulator towards the Helper Node 1
targeted at the specific route (e.g., routeA). Initially, no
traffic would be observed on the egress interface as routeA is
not present.
O. Perform a Graceful Restart Trigger Event on the DUT and note the
time. This is the GREventTime.
P. Remove the policy on Helper Node 1.
Q. Record the time when the traffic targeted towards routeA is
received on the egress interface.
This is TRr(DUT, routeA), also called RecTime(Rt-A).
R. The following equation represents the Graceful Restart
Convergence Time.
Graceful Restart Convergence Time(Rt-A) = ((RecTime(Rt-A) -
GREventTime) - RIB-IN)
S. It is assumed in this test case that after a switchover is
triggered on the DUT, it will not have any cycles to process the
BGP Refresh messages. The reason for this assumption is that
there is a narrow window of time where after switchover, when we
remove the policy from Helper Node 1, implementations might
generate Route Refresh automatically and this request might be
serviced before the DUT actually switches over and re-establishes
BGP adjacencies with the peers.
6. Reporting Format
For each test case, it is recommended that the reporting tables below
are completed, and all time values SHOULD be reported with resolution
as specified in [RFC4098].
Parameter Units or Description
=========================== ==========================
Test case Test case number
Test topology 1, 2, 3, or 4
Parallel links Number of parallel links
Interface type Gigabit Ethernet (GigE),
Packet over SONET (POS), ATM, other
Convergence Event Hard reset, soft reset, link
failure, or other defined
eBGP sessions Number of eBGP sessions
iBGP sessions Number of iBGP sessions
eBGP neighbor Number of eBGP neighbors
iBGP neighbor Number of iBGP neighbors
Routes per peer Number of routes
Total unique routes Number of routes
Total non-unique routes Number of routes
IGP configured IS-IS, OSPF, static, or other
Route mixture Description of route mixture
Route packing Number of routes included in an update
Policy configured Yes, No
SIDR origin authentication Yes, No
[RFC7115]
bgp-sec [BGPsec] Yes, No
Packet size offered Bytes
to the DUT
Offered load Packets per second
Packet sampling interval Seconds
on Tester
Forwarding delay threshold Seconds
Timer values configured on DUT
Interface failure Seconds
indication delay
Hold time Seconds
MinRouteAdvertisementInterval Seconds
(MRAI)
MinASOriginationInterval Seconds
(MAOI)
Keepalive time Seconds
ConnectRetry Seconds
TCP parameters for DUT and Tester
Maximum Segment Size (MSS) Bytes
Slow start threshold Bytes
Maximum window size Bytes
Test Details:
a. If the Offered Load matches a subset of routes, describe how this
subset is selected.
b. Describe how the convergence event is applied; does it cause
instantaneous traffic loss or not?
c. If there is any policy configured, describe the configured
policy.
Complete the table below for the initial convergence event and the
reversion convergence event.
Parameter Unit
=========================== ==========================
Convergence Event Initial or reversion
Traffic Forwarding Metrics
Total number of packets Number of packets
offered to the DUT
Total number of packets Number of packets
forwarded by the DUT
Connectivity packet loss Number of packets
Convergence packet loss Number of packets
Out-of-order packets Number of packets
Duplicate packets Number of packets
Convergence Benchmarks
Rate-Derived Method [RFC6412]:
First route convergence Seconds
time
Full convergence time Seconds
Loss-Derived Method [RFC6412]:
Loss-Derived convergence Seconds
time
Route-Specific (R-S) Loss-Derived
Method:
Minimum R-S convergence Seconds
time
Maximum R-S convergence Seconds
time
Median R-S convergence Seconds
time
Average R-S convergence Seconds
time
Loss of Connectivity (LoC) Benchmarks
Loss-Derived Method:
Loss-Derived loss of Seconds
connectivity period
Route-Specific Loss-Derived
Method:
Minimum LoC period [n] Array of seconds
Minimum Route LoC period Seconds
Maximum Route LoC period Seconds
Median Route LoC period Seconds
Average Route LoC period Seconds
7. Security Considerations
Benchmarking activities as described in this memo are limited to
technology characterization using controlled stimuli in a laboratory
environment, with dedicated address space and the constraints
specified in the sections above.
The benchmarking network topology is an independent test setup and
MUST NOT be connected to devices that may forward the test traffic
into a production network or misroute traffic to the test management
network.
Further, benchmarking is performed on a "black-box" basis, relying
solely on measurements observable and external to the DUT/SUT.
Special capabilities SHOULD NOT exist in the DUT/SUT specifically for
benchmarking purposes. Any implications for network security arising
from the DUT/SUT SHOULD be identical in the lab and in production
networks.
8. References
8.1. Normative References
[IEEE.802.11]
IEEE, "IEEE Standard for Information technology --
Telecommunications and information exchange between
systems Local and metropolitan area networks -- Specific
requirements Part 11: Wireless LAN Medium Access Control
(MAC) and Physical Layer (PHY) Specifications",
IEEE 802.11-2012, DOI 10.1109/ieeestd.2012.6178212, April
2012, <http://ieeexplore.ieee.org/servlet/
opac?punumber=6178209>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<http://www.rfc-editor.org/info/rfc2119>.
[RFC2918] Chen, E., "Route Refresh Capability for BGP-4", RFC 2918,
DOI 10.17487/RFC2918, September 2000,
<http://www.rfc-editor.org/info/rfc2918>.
[RFC4098] Berkowitz, H., Davies, E., Ed., Hares, S., Krishnaswamy,
P., and M. Lepp, "Terminology for Benchmarking BGP Device
Convergence in the Control Plane", RFC 4098,
DOI 10.17487/RFC4098, June 2005,
<http://www.rfc-editor.org/info/rfc4098>.
[RFC4271] Rekhter, Y., Ed., Li, T., Ed., and S. Hares, Ed., "A
Border Gateway Protocol 4 (BGP-4)", RFC 4271,
DOI 10.17487/RFC4271, January 2006,
<http://www.rfc-editor.org/info/rfc4271>.
[RFC6412] Poretsky, S., Imhoff, B., and K. Michielsen, "Terminology
for Benchmarking Link-State IGP Data-Plane Route
Convergence", RFC 6412, DOI 10.17487/RFC6412, November
2011, <http://www.rfc-editor.org/info/rfc6412>.
8.2. Informative References
[BGPsec] Lepinski, M. and K. Sriram, "BGPsec Protocol
Specification", Work in Progress, draft-ietf-sidr-bgpsec-
protocol-15, March 2016.
[RFC1242] Bradner, S., "Benchmarking Terminology for Network
Interconnection Devices", RFC 1242, DOI 10.17487/RFC1242,
July 1991, <http://www.rfc-editor.org/info/rfc1242>.
[RFC1983] Malkin, G., Ed., "Internet Users' Glossary", FYI 18,
RFC 1983, DOI 10.17487/RFC1983, August 1996,
<http://www.rfc-editor.org/info/rfc1983>.
[RFC2285] Mandeville, R., "Benchmarking Terminology for LAN
Switching Devices", RFC 2285, DOI 10.17487/RFC2285,
February 1998, <http://www.rfc-editor.org/info/rfc2285>.
[RFC2545] Marques, P. and F. Dupont, "Use of BGP-4 Multiprotocol
Extensions for IPv6 Inter-Domain Routing", RFC 2545,
DOI 10.17487/RFC2545, March 1999,
<http://www.rfc-editor.org/info/rfc2545>.
[RFC4724] Sangli, S., Chen, E., Fernando, R., Scudder, J., and Y.
Rekhter, "Graceful Restart Mechanism for BGP", RFC 4724,
DOI 10.17487/RFC4724, January 2007,
<http://www.rfc-editor.org/info/rfc4724>.
[RFC4760] Bates, T., Chandra, R., Katz, D., and Y. Rekhter,
"Multiprotocol Extensions for BGP-4", RFC 4760,
DOI 10.17487/RFC4760, January 2007,
<http://www.rfc-editor.org/info/rfc4760>.
[RFC5925] Touch, J., Mankin, A., and R. Bonica, "The TCP
Authentication Option", RFC 5925, DOI 10.17487/RFC5925,
June 2010, <http://www.rfc-editor.org/info/rfc5925>.
[RFC6414] Poretsky, S., Papneja, R., Karthik, J., and S. Vapiwala,
"Benchmarking Terminology for Protection Performance",
RFC 6414, DOI 10.17487/RFC6414, November 2011,
<http://www.rfc-editor.org/info/rfc6414>.
[RFC7115] Bush, R., "Origin Validation Operation Based on the
Resource Public Key Infrastructure (RPKI)", BCP 185,
RFC 7115, DOI 10.17487/RFC7115, January 2014,
<http://www.rfc-editor.org/info/rfc7115>.
Acknowledgements
We would like to thank Anil Tandon, Arvind Pandey, Mohan Nanduri, Jay
Karthik, and Eric Brendel for their input and discussions on various
sections in the document. We also like to acknowledge Will Liu,
Hubert Gee, Semion Lisyansky, and Faisal Shah for their review and
feedback on the document.
Authors' Addresses
Rajiv Papneja
Huawei Technologies
Email: rajiv.papneja@huawei.com
Bhavani Parise
Skyport Systems
Email: bparise@skyportsystems.com
Susan Hares
Huawei Technologies
Email: shares@ndzh.com
Dean Lee
IXIA
Email: dlee@ixiacom.com
Ilya Varlashkin
Google
Email: ilya@nobulus.com