INTRODUCTION
------------
The IEEE 802.1ag standard is a set of protocols for Ethernet OAM
(Operations, Administration, and Management). The dot1ag-utils software
package is an Open Source (new BSD License) implementation of the
IEEE 802.1ag protocol and is supported on Arista Networks switches and
Linux, FreeBSD and MacOSX servers. It provides several debugging tools
that interact with IEEE 802.1ag enabled routers and switches. The package
implements a loopback message initiator (ethping), a link trace message
initiator (ethtrace) and a daemon (dot1agd) that responds to loopback
messages and link trace messages. Sending and receiving of continuity
check messages is implemented in the dot1ag_ccd daemon.

Currently, the dot1ag-utils implement the Down MEP functionality only.
The main focus at the moment is a setup where the dot1ag-utils are
run on an interface of a server which is connected to an Ethernet switch.

USE CASES
---------

(1) Ping and trace to Ethernet MAC addresses from a server.

                                                    MIP
                                              00:14:0d:0b:10:c4   MEP
                                                      |    00:1b:c0:97:38:c6
                                                      |                | 
                                                      V                V
+--------+       +--------+     +----------------+    +----------------+
| server +-------+ switch +-----+ 802.1ag switch +----+ 802.1ag switch |
+--------+       +--------+     +----------------+    +----------------+

server# ethping -ieth5 -v123 -l7 -c5 00:14:0d:0b:10:c4
Sending CFM LBM to 00:14:0d:0b:10:c4
64 bytes from 00:14:0d:0b:10:c4, sequence 209175278, 4.256 ms
64 bytes from 00:14:0d:0b:10:c4, sequence 209175279, 0.410 ms
64 bytes from 00:14:0d:0b:10:c4, sequence 209175280, 0.412 ms
64 bytes from 00:14:0d:0b:10:c4, sequence 209175281, 0.410 ms
64 bytes from 00:14:0d:0b:10:c4, sequence 209175282, 0.440 ms


server# ethtrace -i eth5 -v 123 -l7 00:1b:c0:97:38:c6
Sending CFM LTM probe to 00:1b:c0:97:38:c6
ttl 1: LTM with id 284917984
	reply from 00:14:0d:0b:10:c1, id=284917984, ttl=0, RlyFDB
ttl 2: LTM with id 284917985
	reply from 00:14:0d:0b:10:c1, id=284917985, ttl=1, RlyFDB
	reply from 00:14:0d:0b:10:c4, id=284917985, ttl=0, RlyFDB
ttl 3: LTM with id 284917986
	reply from 00:14:0d:0b:10:c1, id=284917986, ttl=2, RlyFDB
	reply from 00:14:0d:0b:10:c4, id=284917986, ttl=1, RlyFDB
	reply from 00:1b:c0:97:38:c6, id=284917986, ttl=0, RlyHit

-----------------------------------------

(2) Connect a server to a switch and let the server respond to
Ethernet ping and trace messages.

                                   dot1agd
                                  +--------+
                                  | server |
                                  +---+----+
                                      | v1
   v1    +----------------+  v1   +---+----+  v1   +----------------+
---------+ 802.1ag switch +-------+ switch +-------+ 802.1ag switch +-----
         +----------------+       +--------+       +----------------+

The server is connected to the middle switch on VLAN v1. It can interact
with IEEE 802.1ag enabled switches. So you can L2 ping and trace to the
middle server (the server will respond) even though the switch does not
support 802.1ag itself.

When you also run the dot1ag_ccd daemon on the server, this setup can
send and receive continuity check messages too.

The advantage is that the server is connected to the switch at
L2 only. It does not need an IP address. So the security risk
is minimal. The server cannot be hacked via IP protocols.


SUPPORTED PLATFORMS
-------------------
The 8021ag-utils have been tested on:
Arista Networks EOS 4.7.3
CentOS 5.6
FreeBSD 8.x
MacOSX 10.6.7, 10.7
NetBSD
Ubuntu 10.04.2 LTS

Interoperability tests have been done with:
Actelis
Alcatel
Cisco C3750-ME 12.2(55)SE
Juniper T1600 JUNOS 10.3I
Nortel MERS 8600 6.0.4.0OE

CONTACT INFORMATION
-------------------
Please send questions, bugs, patches, etc to rvdp@sara.nl or nrg@sara.nl.

You can also join the mailman mailing list:
https://horus.sara.nl/mailman/listinfo/dot1ag-utils

The dot1ag-utils can be downloaded from:
http://nrg.sara.nl/dot1ag-utils