ThingNetwork.io

Ostinato is a great open source traffic generation tool, lately I have been using it for some virtual labs using GNS3 with Nokia SROS based routers, however there is no reason what I am doing here cannot be adapted to any routing system that supports PIM and IGMP.

This post should be the final in the my current series on using Ostinato to generate and received multicast traffic flows.

So a quick recap of the network topology:

Test Scenario

We shall be transmitting multicast IP packets (destination 239.0.0.9) from the Ostinato Drone Port1 (Connected to R5), while Ostinato Drone Port2 (Connected to R4) and Port3 (Connected to R3) shall use IGMP to request reception of that multicast stream.

The previous blog two posts described constructing the multicast router network and the initial part of the Ostinato where I created IP hosts that connect to the network

Now that the precursors have been done, lets continue on by crafting the multicast stream that will be transmitted from Ostinato Port1 to R5:

In Ostinato, in the Ports and Streams window pane select Port1. Make sure the streams tab is visible and right Click to create a new stream – Stream 1 will be created with a blank name. If you click in that area you can give the stream a name (I will use MC-239.0.0.9)

Right Click on Stream 1 and select edit stream. There are multiple tabs available, pick the protocol selection tab and Select:

• L1 – Mac
• VLAN – untagged
• L2 – Ethernet II
• L3 – IPv4
• L4 – UDP
• L5 – None

Then select the Protocol Data Tab and populate the following information

• Media Access Protocol
  • Destination: 01:00:5e:00:00:09 Mode:Fixed (For IP Multicast Group 239.0.0.9)
  • Source: 48:00:01:2E:10:83 Mode:Fixed (From the device configuration ToR5-OST-e1)

  

• Internet Protocol Version 4
  • Source: 10.0.5.1
  • Destination: 239.0.0.9

  

• User Datagram Protocol
  • Override Source Port – 222
  • Override Desination Port – 222

  

Now we create the Stream Control Options:

• Send 100 Packets
• Rate 10 Packets/Second
• After this stream: Stop

What this means is when we run this stream, it will attempt to send 10 multicast IP packets encapsulated in multicast Ethernet Frames each second for a period of 10 seconds and then it shall stop.

• We apply the configuration (click the Apply button in the upper right hand corner of the window)
• Click on Port 0
• Select Resolve Device Neighbors
• Click on start packet capture (looks like a speaker icon)
• Select clear statistics (this port or all ports)
• Then click start

After 10 seconds, we should have seen around 100 packets transmitted (it could be slightly more if ARP or other processes were active)

Click on stop packet capture (looks like a speaker icon with a line through it)
Click on view packet capture (looks like a magnifying glass)

If we look at R5, we can see that it is aware that there is multicast traffic entering from Ostinato:

A:R5# show router pim group

===============================================================================
Legend:  A = Active   S = Standby
===============================================================================
PIM Groups ipv4
===============================================================================
Group Address               Type                Spt Bit  Inc Intf       No.Oifs
   Source Address              RP                  State    Inc Intf(S)
-------------------------------------------------------------------------------
239.0.0.9                   (S,G)                        OST-e1         0
   10.0.5.1                    10.10.10.2
-------------------------------------------------------------------------------
Groups : 1
===============================================================================

This appears to be working – so we shall proceed to configuring the other Ostinato ports to send IGMPv2 Group Reports for 239.0.0.9 and see if they will receive the multicast traffic.

Ostinato Port2 to R4 (Multicast Receiver):

Following the same concept as what was done for Port1, we will focus primarily on the differences. In Ostinato, in the Ports and Streams window pane select Port2. Make sure the streams tab is visible and right Click to create a new stream – Stream 1 will be created with a blank name. If you click in that area you can give the stream a name (I will use MJ-239.0.0.9)

Right Click on Stream 1 and select edit stream. There are multiple tabs available, pick the protocol selection tab and Select:

• L1 – Mac
• VLAN – untagged
• L2 – Ethernet II
• L3 – IPv4
• L4 – IGMP
• L5 – None

Then select the Protocol Data Tab and populate the following information

• Media Access Protocol
  • Destination: 01:00:5e:00:00:02 Mode:Fixed (For IP Multicast Group 224.0.0.2)
  • Source: 34:00:02:BF:69:5B Mode:Fixed (From the device configuration ToR4-OST-e2)
  • Source: 10.0.4.1
  • Destination: 224.0.0.2
  • TTL: 1
• Internet Group Management Protocol
  • Message Type – 22 IGMPv2 Report
  • Group Address 239.0.0.9

Now we create the Stream Control Options:

• Send 1 Packets
• Rate 0.1 Packets/Second
• After this stream: Goto First

What this means is when we run this stream, it will attempt to send 1 IGMP Join every 10 seconds continuously.

• We apply the configuration (click the Apply button in the upper right hand corner of the window)Click on Port 2
• Click on start packet capture (looks like a speaker icon)
• Select clear statistics (this port or all ports)
• Select Resolve Device Neighbors
• Then click start

After 10 seconds, we should have seen a few packets transmitted (it could be slightly more if ARP or other processes were active) we probably would be receiving very little as well assuming the multicast source is not currently transmitting.

Click on stop packet capture (looks like a speaker icon with a line through it)
Click on view packet capture (looks like a magnifying glass)

A:R4# show router igmp group
===============================================================================
IGMP Interface Groups
===============================================================================

(*,239.0.0.9)                                             UpTime: 0d 00:01:44
    Fwd List  : OST-e2
-------------------------------------------------------------------------------
Entries : 1
===============================================================================
IGMP Host Groups
===============================================================================
No Matching Entries
===============================================================================
IGMP SAP Groups
===============================================================================
No Matching Entries
===============================================================================

This looks good, we shall configure a similar stream for Port 3 on the drone.

Ostinato Port3 to R3 (Multicast Receiver)::

Following the same concept as what was done for Port2, on Port3 create stream MJ-239.0.0.9.

Right Click on Stream 1 and select edit stream. There are multiple tabs available, pick the protocol selection tab and Select:

• L1 – Mac
• VLAN – untagged
• L2 – Ethernet II
• L3 – IPv4
• L4 – IGMP
• L5 – None

Then select the Protocol Data Tab and populate the following information

• Media Access Protocol
  • Destination: 01:00:5e:00:00:02 Mode:Fixed (For IP Multicast Group 224.0.0.2)
  • Source: 10:00:03:29:03:98 Mode:Fixed (From the device configuration ToR3-OST-e3)
  • Source: 10.0.3.1
  • Destination: 224.0.0.2
  • TTL: 1
• Internet Group Management Protocol
  • Message Type – 22 IGMPv2 Report
  • Group Address 239.0.0.9

Now we create the Stream Control Options:

• Send 1 Packets
• Rate 0.1 Packets/Second
• After this stream: Goto First

What this means is when we run this stream, it will attempt to send 1 IGMP Join every 10 seconds continuously.

• We apply the configuration (click the Apply button in the upper right hand corner of the window)
• Click on Port 3
• Select clear statistics (this port or all ports)
• Select Resolve Device Neighbors
• Then click start

After a few seconds, we should be able to see if R3 has an IGMP member for group 239.0.0.9

A:R3# show router igmp group
===============================================================================
IGMP Interface Groups
===============================================================================

(*,239.0.0.9)                                             UpTime: 0d 00:00:03
    Fwd List  : OST-e3
-------------------------------------------------------------------------------
Entries : 1
===============================================================================
IGMP Host Groups
===============================================================================
No Matching Entries
===============================================================================
IGMP SAP Groups
===============================================================================
No Matching Entries
===============================================================================

Full End to End Test – Multicast Sender and Receivers

The sequence of events will be:

• Resolve Device Neighbors on Ports 1/2/3
• Start Ports 2 and 3 so they are waiting to receive multicast traffic.
• Start Port 1 which should send 100 Packets to Group 239.0.0.9 in 10 seconds
• Look at the stats to verify that Ports 2 and 3 receive 100 packets.

Multicast Forwarding Topology:

A:R5# show router pim group 239.0.0.9 source 10.0.5.1 detail | match Intf
Incoming Intf      : OST-e1
Outgoing Intf List : R1, R2

A:R1# show router pim group 239.0.0.9 source 10.0.5.1 detail | match Intf
Incoming Intf      : R5
Outgoing Intf List : R3

A:R2# show router pim group 239.0.0.9 source 10.0.5.1 detail | match Intf
Incoming Intf      : R5
Outgoing Intf List : R4

A:R3# show router pim group 239.0.0.9 source 10.0.5.1 detail | match Intf
Incoming Intf      : R1
Outgoing Intf List : OST-e3

A:R4# show router pim group 239.0.0.9 source 10.0.5.1 detail | match Intf
Incoming Intf      : R2
Outgoing Intf List : OST-e2

Individual Streams, or the entire test session can be saved so you don’t need to recreate the test scenario each time.

This was a somewhat long example as to what you can do with Ostinato, however being able to do multicast testing using more than igmp static joins on routers and pings to multicast addresses on a virtual environment is quite helpful.

I am by no means an expert with this tool and I am sure that there are ways to optimise my workflow to achieve similar results.  Working through this example was fun – as I find having a particular problem to solve is usually a good way to try to learn how to use a tool and now I am better armed for other situations.

As a note – from my preliminary investigations, unicast traffic flows seems to be generally more straight forward as Ostinato allows you to populate some stream layer information (such as MAC addresses) via ARP (this is using mode resolved instead of mode fixed – however this is dependant on defining the appropriate end devices)

Here is the GNS3 Topology for this blog post:

For the moment let us ignore Ostinato and the Cloud parts of our topology and initially concentrate on building the network infrastructure.

• OSPF is the IGP
• PIM is enabled on all inter-router interfaces
• Candidate BSRs are R3 (Priority 100) and R4 (Priority 90) – R3 should become the BSR (Like Basketball, highest wins)
• Candidate RPs for 224.0.0.0/4 are R2 (Priority 90) and R4 (Priority 100) – R2 should become the RP (Like Golf, lowest wins)

/configure
    system
        name "R1"
    exit
    card 1
        card-type iom3-xp-b
        mda 1
            mda-type m5-1gb-sfp-b
            no shutdown
        exit
        no shutdown
    exit
    port 1/1/1
        ethernet
        exit
        no shutdown
    exit
    port 1/1/3
        ethernet
        exit
        no shutdown
    exit
    port 1/1/4
        ethernet
        exit
        no shutdown
    exit
    router
        interface "R2"
            address 10.1.2.1/27
            port 1/1/1
            no shutdown
        exit
        interface "R3"
            address 10.1.3.1/27
            port 1/1/3
            no shutdown
        exit
        interface "R5"
            address 10.1.5.1/27
            port 1/1/4
            no shutdown
        exit
        interface "system"
            address 10.10.10.1/32
            no shutdown
        exit
        ospf 0
            area 0.0.0.0
                interface "system"
                    no shutdown
                exit
                interface "R2"
                    no shutdown
                exit
                interface "R3"
                    no shutdown
                exit
                interface "R5"
                    no shutdown
                exit
            exit
            no shutdown
        exit
        pim
            interface "system"
            exit
            interface "R2"
            exit
            interface "R3"
            exit
            interface "R5"
            exit
            no shutdown
                bsr-candidate
                    shutdown
                exit
                rp-candidate
                    shutdown
                exit
        exit
exit all

 

/configure
    system
        name "R2"
    exit
    card 1
        card-type iom3-xp-b
        mda 1
            mda-type m5-1gb-sfp-b
            no shutdown
        exit
        no shutdown
    exit
    port 1/1/1
        ethernet
        exit
        no shutdown
    exit
    port 1/1/2
        ethernet
        exit
        no shutdown
    exit
    port 1/1/3
        ethernet
        exit
        no shutdown
    exit
    router
        interface "R1"
            address 10.1.2.2/27
            port 1/1/1
            no shutdown
        exit
        interface "R4"
            address 10.2.4.2/27
            port 1/1/3
            no shutdown
        exit
        interface "R5"
            address 10.2.5.2/27
            port 1/1/2
            no shutdown
        exit
        interface "system"
            address 10.10.10.2/32
            no shutdown
        exit
        ospf 0
            area 0.0.0.0
                interface "system"
                    no shutdown
                exit
                interface "R1"
                    no shutdown
                exit
                interface "R4"
                    no shutdown
                exit
                interface "R5"
                    no shutdown
                exit
            exit
            no shutdown
        exit
        pim
            interface "system"
            exit
            interface "R1"
            exit
            interface "R4"
            exit
            interface "R5"
            exit
            rp
                static
                exit
                bsr-candidate
                    shutdown
                exit
                rp-candidate
                    address 10.10.10.2
                    group-range 224.0.0.0/4
                    priority 90
                    no shutdown
                exit
            exit
            no shutdown
        exit
exit all

 

/configure
    system
        name "R3"
    exit
    card 1
        card-type iom3-xp-b
        mda 1
            mda-type m5-1gb-sfp-b
            no shutdown
        exit
        no shutdown
    exit
    port 1/1/1
        ethernet
        exit
        no shutdown
    exit
    port 1/1/3
        ethernet
        exit
        no shutdown
    exit
    router
        interface "R1"
            address 10.1.3.3/27
            port 1/1/3
            no shutdown
        exit
        interface "R4"
            address 10.3.4.3/27
            port 1/1/1
            no shutdown
        exit
        interface "system"
            address 10.10.10.3/32
            no shutdown
        exit
        ospf 0
            area 0.0.0.0
                interface "system"
                    no shutdown
                exit
                interface "R1"
                    no shutdown
                exit
                interface "R4"
                    no shutdown
                exit
            exit
            no shutdown
        exit
        pim
            interface "system"
            exit
            interface "R1"
            exit
            interface "R4"
            exit
            rp
                static
                exit
                bsr-candidate
                    priority 100
                    address 10.10.10.3
                    no shutdown
                exit
                rp-candidate
                    shutdown
                exit
            exit
            no shutdown
        exit
exit all

 

/configure
    system
        name "R4"
    exit
    card 1
        card-type iom3-xp-b
        mda 1
            mda-type m5-1gb-sfp-b
            no shutdown
        exit
        no shutdown
    exit
    port 1/1/1
        ethernet
        exit
        no shutdown
    exit
    port 1/1/3
        ethernet
        exit
        no shutdown
    exit
    router
        interface "R2"
            address 10.2.4.4/27
            port 1/1/3
            no shutdown
        exit
        interface "R3"
            address 10.3.4.4/27
            port 1/1/1
            no shutdown
        exit
        interface "system"
            address 10.10.10.4/32
            no shutdown
        exit
        ospf 0
            area 0.0.0.0
                interface "system"
                    no shutdown
                exit
                interface "R2"
                    no shutdown
                exit
                interface "R3"
                    no shutdown
                exit
            exit
            no shutdown
        exit
        pim
            interface "system"
            exit
            interface "R2"
            exit
            interface "R3"
            exit
            rp
                static
                exit
                bsr-candidate
                    priority 90
                    address 10.10.10.4
                    no shutdown
                exit
                rp-candidate
                    address 10.10.10.4
                    group-range 224.0.0.0/4
                    priority 100
                    no shutdown
                exit
            exit
            no shutdown
        exit
exit all

 

/configure
    system
        name "R5"
    exit
    card 1
        card-type iom3-xp-b
        mda 1
            mda-type m5-1gb-sfp-b
            no shutdown
        exit
        no shutdown
    exit
    port 1/1/2
        ethernet
        exit
        no shutdown
    exit
    port 1/1/3
        ethernet
        exit
        no shutdown
    exit
    router
        interface "R1"
            address 10.1.5.5/27
            port 1/1/3
            no shutdown
        exit
        interface "R2"
            address 10.2.5.5/27
            port 1/1/2
            no shutdown
        exit
        interface "system"
            address 10.10.10.5/32
            no shutdown
        exit
        ospf 0
            area 0.0.0.0
                interface "system"
                    no shutdown
                exit
                interface "R1"
                    no shutdown
                exit
                interface "R2"
                    no shutdown
                exit
            exit
            no shutdown
        exit
        pim
            interface "R1"
            exit
            interface "R2"
            exit
            rp
                static
                exit
                bsr-candidate
                    shutdown
                exit
                rp-candidate
                    shutdown
                exit
            exit
            no shutdown
        exit
exit all

Initial Multicast Verification:

A:R4# show router pim status | match " BSR" post-lines 5
BSR State                         : Candidate BSR

Elected BSR
    Address                       : 10.10.10.3
    Expiry Time                   : 0d 00:01:15
    Priority                      : 100
    Hash Mask Length              : 30
    Up Time                       : 0d 00:06:58
Candidate BSR
    Admin State                   : Up
    Oper State                    : Up
    Address                       : 10.10.10.4
    Priority                      : 90
    Hash Mask Length              : 30

Although R4 was a possible BSR, it knows R3 has the job.

Regarding the RP? Well the BSR sends all RP candidates and lets the PIM enabled routers decide themselves – in this case, lowest priority (R2) will be what matters

A:R1# show router pim rp

===============================================================================
PIM RP Set ipv4
===============================================================================
Group Address                                                Hold Expiry
  RP Address                                   Type     Prio Time Time
-------------------------------------------------------------------------------
224.0.0.0/4
  10.10.10.2                                   Dynamic  90   150  0d 00:02:06
  10.10.10.4                                   Dynamic  100  150  0d 00:02:06
-------------------------------------------------------------------------------
Group Prefixes : 1
===============================================================================

So lets look at Ostinato.

There are two parts to it

1. the Drone (Server that generates/receives traffic) which is a virtual appliance in my GNS3 topology
2. the GUI which is running on my desktop and connects over the network to the Drone

What may not be obvious is that I run GNS3 on a separate device (an desktop pc given 16GB of ram which runs Ubuntu and starts the GNS3 server upon bootup) as a remote server which I connect to via the GNS3 GUI on my PC.

The Ubuntu Server /etc/network/interfaces configuration is a little different to most as a bridge interface is used rather than the eth0 interface directly:

adam@gns3:~$cat /etc/network/interfaces
# The loopback network interface
auto lo
iface lo inet loopback

# The primary network interface
iface eth0 inet manual
auto pnet0
iface pnet0 inet dhcp
    bridge_ports eth0
    bridge_stp off

This comes in handy because I can then add other interfaces to the bridge and be part of the same IP subnet. The follow command makes sure the gns3 user (which the GNS3 server application runs as) can control the tunnel interface (tap0) and it is added to bridge pnet0 and is enabled.

adam@gns3:~$cat /etc/rc.local
tunctl -u gns3
brctl addif pnet0 tap0
ifconfig tap0 up
exit 0

Within GNS3, a cloud that is attached to nio_tap:tap0 is created and the link is attached to the Ostinato VM interface e0.

Lets fire up the Ostinato VM (I downloaded it from Bernhard Ehlers’s site – I use the qcow2 version because I’m running it as a qemu app) and see if it has world connectivity:

Core Linux

username 'gns3', password 'gns3'
Run filetool.sh -b if you want to save your changes
box login: tc
login: can't change directory to '/home/tc'
   ( '>')
  /) TC (\   Core is distributed with ABSOLUTELY NO WARRANTY.
 (/-_--_-\)           www.tinycorelinux.net

tc@box:/$ netstat -l | grep tcp
tcp        0      0 0.0.0.0:7878            0.0.0.0:*               LISTEN

tc@box:/$tc@box:/$ ifconfig eth0 | grep "inet addr"
          inet addr:192.168.1.66  Bcast:192.168.1.255  Mask:255.255.255.0
tc@box:/$ ping 8.8.4.4 -c 5
PING 8.8.4.4 (8.8.4.4): 56 data bytes
64 bytes from 8.8.4.4: seq=0 ttl=55 time=25.842 ms
64 bytes from 8.8.4.4: seq=1 ttl=55 time=25.151 ms
64 bytes from 8.8.4.4: seq=2 ttl=55 time=24.438 ms
64 bytes from 8.8.4.4: seq=3 ttl=55 time=25.739 ms
64 bytes from 8.8.4.4: seq=4 ttl=55 time=25.540 ms

--- 8.8.4.4 ping statistics ---
5 packets transmitted, 5 packets received, 0% packet loss
round-trip min/avg/max = 24.438/25.342/25.842 ms

The Ostinato drone is on our network and ready to rock, we can see the drone is listening on tcp port 7878 for the Ostinato GUI and it has reachability on the LAN to the router and off to the wild and woolly internet.

The Next Post will focus on connecting Ostinato up to the topology and using it to play with multicast.

We shall:

• Connect he Ostinato GUI to the Drone
• Create Virtual Devices in Ostinato to appear as ARP/ICMP responders to the network
• Create a multicast stream (Mac/EthII/IPv4/UDP) to be sent to the network
• Create streams which send IGMP reports to the network so the network will forward multicast packets to those ports