IP SLA

Note: to experiment with IP SLA, use the GNS3 software-defined networking appliance.

internet protocol service level agreements

IP SLA = internet protocol service level agreements; these are used by routers to keep WANs running smoothly.

IP SLA Configuration to Generate Dummy Traffic

You can use IP SLA to generate traffic between routers and create bottlenecks. This can also be simulated using the GNS3 virtual networking appliance. See https://gns3vault.com/blog/gns3-ip-sla-traffic-generator/

The following configuration will generate ping (ICMP), DNS, HTTP, HTTPS, Telnet, SSH and RTP traffic on a router:

! ICMP Echo
ip sla monitor 1
type echo protocol ipIcmpEcho 192.168.23.3
timeout 0
frequency 9
ip sla monitor schedule 1 start-time now life forever

! DNS Request
ip sla monitor 2
type dns target-addr www.gns3vault.com name-server 192.168.23.3
timeout 0
frequency 9
ip sla monitor schedule 2 start-time now life forever

! G711 conversation
ip sla monitor 3
type jitter dest-ipaddr 192.168.23.3 dest-port 16384 codec g711ulaw codec-numpackets 50 codec-size 160 codec-interval 20
timeout 0
frequency 1
ip sla monitor schedule 3 start-time now life forever

! G729 conversation
ip sla monitor 4
type jitter dest-ipaddr 192.168.23.2 dest-port 16385 codec g729a codec-numpackets 50 codec-size 20 codec-interval 20
timeout 0
frequency 1
ip sla monitor schedule 4 start-time now life forever

! HTTP GET Traffic
ip sla monitor 5
type http operation get url http://192.168.23.3
frequency 60
ip sla monitor schedule 5 start-time now life forever

! TCPConnect to Telnet
ip sla monitor 6
type tcpConnect dest-ipaddr 192.168.23.3 dest-port 23 control disable
timeout 1000
frequency 2
ip sla monitor schedule 6 life forever start-time now

! TCPConnect to HTTPS
ip sla monitor 7
type tcpConnect dest-ipaddr 192.168.23.3 dest-port 443 control disable
timeout 1000
frequency 3
ip sla monitor schedule 7 life forever start-time now

! TCPConnect to FTP
ip sla monitor 8
type tcpConnect dest-ipaddr 192.168.23.3 dest-port 21 control disable
timeout 1000
frequency 1
ip sla monitor schedule 8 life forever start-time now

! TCPConnect to SSH
ip sla monitor 9
type tcpConnect dest-ipaddr 192.168.23.3 dest-port 22 control disable
timeout 1000
frequency 2
ip sla monitor schedule 9 life forever start-time now

Monitoring the fake traffic

Start by enabling NBAR (network based application recognition) on your router, then you'll be able to see traffic flowing through the router's network interface with the command:

(router) # show ip nbar protocol-discovery

FastEthernet0/0
Input                    Output                 
-----                    ---------
Protocol                 Packet Count             Packet Count           Byte Count               Byte Count 
---------------------------------------------------------------------------------
telnet                   70                       28                     4200                     1974                   1000 
ssh                      64                       24                     3840                     1440                   1000 
secure-http              40                       15                     2400                     900                    1000 
icmp                     14                       18                     1452                     1716                   0 
ftp                      30                       15                     1800                     900