Note
It is important to note that though its name, P4Emu/pcap is not emulating V1Model. P4Emu is emulating router.p4 packet processing logic and uses a packet forwarding library to effectively transmit packets at specific ingress port to the right egress port defined by freeRouter control plane message.

Diagram

Image RemovedImage Added

[ #005 ] - Cookbook

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Expand

title	Install FreeRouter as per #001 article: "Create freeRouter environment"

Code Block

language	bash
theme	Midnight
title	flush enp0s3 so that it can be controlled by dpdk

ip addr flush enp0s3

Info

title	Source Wikipedia:

You can add a second Host-only interface (enp0s8) in VirtualBox in order to connect the ubuntu focal VM guest as you might lose connection when you flushed enp0s3.

Code Block

language	bash
theme	Midnight

mkdir -p ~/freeRouter/bin ~/freeRouter/lib ~/freeRouter/etc ~/freeRouter/log
cd ~/freeRouter/lib
wget http://freerouter.nop.hu/rtr.jar

Code Block

language	bash
theme	Midnight
title	Update & Upgrade system

tree freeRouter
freeRouter
├── bin   # binary files      
├── etc   # configuration files      
├── lib   # library files      
└── log   # log files

...

Expand

title	Create configuration files for router: freerouter

FreeRouter uses 2 configuration files in order to run, let's write these configuration files for R1 in ~/freeRouter/etc

Code Block

language	bash
theme	Midnight
title	freeRouter hardware configuration file: p4-freerouter-hw.txt

int eth0 eth 0000.1111.00fb 127.0.0.1 22710 127.0.0.1 22709
tcp2vrf 2323 v1 23
tcp2vrf 9080 v1 9080

Code Block

language	bash
theme	Midnight
title	freeRouter software configuration file: p4-freerouter-sw.txtconfiguration file: p4-freerouter-sw.txt

hostname pcap-freerouter
buggyhostname p4-freerouter
buggy
!
!
prefix-list p4
 sequence 10 permit 0.0.0.0/0 ge 0 le 0
 exit
!
prefix-list p6
 sequence 10 permit ::/0 ge 0 le 0
 exit
!
vrf definition v1
 exit
!
interface ethernet0
 description freerouter@P4_CPU_PORT[veth251]
 no shutdown
 no log-link-change
 exit
!
interface sdn1
 description freerouter@sdn1[enp0s3]
 mtu 9000
 macaddr 0072.3e18.1b6f
 vrf forwarding v1
 ipv4 address 192.168.0.131 255.255.255.0
 ipv6 address 2a01:e0a:159:2850::666 ffff:ffff:ffff:ffff::
 ipv6 enable
 no shutdown
 no log-link-change
 exit
!
!
!
!
!
!
!
!
!
!
!
!
!
!
server telnet tel
 security protocol telnet
 no exec authorization
 no login authentication
 vrf v1
 exit
!
server p4lang p4
 export-vrf v1 1
 export-port sdn1 1 0
 interconnect ethernet0
 vrf v1
 exit
!
end

...

Expand

title	Launch freeRouter control plane alongside P4Emu/pcap dataplane

Code Block

language	bash
theme	Midnight
title	Setup P4Emu dataplane communication channel via veth pair and interface adjustment (disable IPv6 at VM guest level, MTU 10240, disable TCP offload etc.)

echo 1 > /proc/sys/net/ipv6/conf/all/disable_ipv6
echo 1 > /proc/sys/net/ipv6/conf/default/disable_ipv6

ip link add veth251 type veth peer name veth250
ip link set veth250  up 
ip link set veth251  up 

ifconfig enp0s3 promisc
ifconfig veth250 promisc
ifconfig veth251 promisc

ip link set dev veth250 up mtu 10240
ip link set dev veth251 up mtu 10240
ip link set dev enp0s3 up mtu 10240
export TOE_OPTIONS="rx tx sg tso ufo gso gro lro rxvlan txvlan rxhash"

for TOE_OPTION in $TOE_OPTIONS; do
    /sbin/ethtool --offload veth250 "$TOE_OPTION" off &> /dev/null
    /sbin/ethtool --offload veth251 "$TOE_OPTION" off &> /dev/null
    /sbin/ethtool --offload enp0s3 "$TOE_OPTION" off &> /dev/null
done

Code Block

language	bash
theme	Midnight
title	freeRouter launch with supplied p4-freerouter-hw.txt and p4-freerouter-sw.txt with a console prompt

java -jar lib/rtr.jar routersc etc/p4-freerouter-hw.txt etc/p4-freerouter-sw.txt
info cfg.cfgInit.doInit:cfgInit.java:556 booting
info cfg.cfgInit.doInit:cfgInit.java:680 initializing hardware
info cfg.cfgInit.doInit:cfgInit.java:687 applying defaults
info cfg.cfgInit.doInit:cfgInit.java:695 applying configuration
info cfg.cfgInit.doInit:cfgInit.java:721 done
welcome
line ready
pcap-freerouter#

Code Block

language	bash
theme	Midnight
title	launch freeRouter pcapInt in order to stitch control plane and P4Emu/pcap dataplane communication

cd ~/freeRouter/bin
./pcapInt.bin veth251 22709 127.0.0.1 22710 127.0.0.1
binded to local port 127.0.0.1 22709.
will send to 127.0.0.1 22710.
pcap version: libpcap version 1.8.1
opening interface veth251 with pcap1.x api
serving others
>

Code Block

language	bash
theme	Midnight
title	Launch P4Emu/pcap software dataplane

sudo ./p4emu.bin  127.0.0.1 9080 0 veth250 enp0s3
cpu port is #0 of 2...
pcap version: libpcap version 1.8.1
connecting 127.0.0.1 9080.
opening interface veth250.
opening interface enp0s3.
rx: 'myaddr4' 'add' '224.0.0.0' '4' '0' '1' '' 
rx: 'myaddr4' 'add' '255.255.255.255' '32' '0' '1' '' 
rx: 'myaddr6' 'add' 'ff00::' '8' '0' '1' '' 
rx: 'myaddr4' 'add' '192.168.0.0' '24' '-1' '1' '' 
rx: 'myaddr4' 'add' '192.168.0.131' '32' '-1' '1' '' 
rx: 'myaddr6' 'add' '2a01:e0a:159:2850::' '64' '-1' '1' '' 
rx: 'myaddr6' 'add' '2a01:e0a:159:2850::666' '128' '-1' '1' '' 
rx: 'myaddr6' 'add' 'fe80::' '64' '-1' '1' '' 
rx: 'mylabel4' 'add' '615589' '1' '' 
rx: 'mylabel6' 'add' '1036348' '1' '' 
rx: 'state' '1' '1' '0' '' 
rx: 'mtu' '1' '9000' '' 
rx: 'portvrf' 'add' '1' '1' '' 
rx: 'keepalive' '' 
rx: 'keepalive' '' 
rx: 'neigh6' 'add' '11120' 'fe80::224:d4ff:fea0:cd3' '00:24:d4:a0:0c:d3' '1' '00:72:3e:18:1b:6f' '1' '' 
rx: 'keepalive' '' 
rx: 'keepalive' '' 
rx: 'keepalive' '' 
rx: 'neigh4' 'add' '29738' '192.168.0.254' '00:24:d4:a0:0c:d3' '1' '00:72:3e:18:1b:6f' '1' '' 
rx: 'keepalive' '' 
rx: 'neigh4' 'add' '40470' '192.168.0.62' 'e0:3f:49:6d:18:99' '1' '00:72:3e:18:1b:6f' '1' '' 
rx: 'keepalive' '' 
rx: 'keepalive' '' 
rx: 'keepalive' '' 
rx: 'keepalive' '' 
rx: 'keepalive' '' 
rx: 'neigh6' 'add' '45820' '2a01:e0a:159:2850:e23f:49ff:fe6d:1899' 'e0:3f:49:6d:18:99' '1' '00:72:3e:18:1b:6f' '1' '' 
rx: 'keepalive' '' 
rx: 'neigh6' 'add' '49055' 'fe80::e23f:49ff:fe6d:1899' 'e0:3f:49:6d:18:99' '1' '00:72:3e:18:1b:6f' '1' '' 
rx: 'neigh6' 'add' '33334' '2a01:e0a:159:2850::
...

...

Expand

title	Check telnet access for freerouter@2323

Code Block

language	bash
theme	Midnight
title	FreeRouter telnet access from Virtualbox VM guest via port 2323

telnet localhost 2323
Trying ::1...
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
welcome
line ready
pcap-freerouter#

Expand

title	Check running-config

Code Block

language	bash
theme	Midnight
title	freerouter running configuration

p4pcap-freerouter#term len 0                                                       
p4pcap-freerouter#sh run                                                           
hostname p4pcap-freerouter
buggy
!
vrf definition v1
 exit
!
interface ethernet0
 description freerouter@P4_CPU_PORT[veth251]
 no shutdown
 no log-link-change
 exit
!
interface sdn1
 description freerouter@sdn1[enp0s3]
 mtu 9000
 macaddr 0072.3e18.1b6f
 vrf forwarding v1
 ipv4 address 192.168.0.131 255.255.255.0
 ipv6 address 2a01:e0a:159:2850::666 ffff:ffff:ffff:ffff::
 ipv6 enable
 no shutdown
 no log-link-change
 exit
!
!
!
!
!
!
!
!
!
!
!
!
!
!
server telnet tel
 security protocol telnet
 no exec authorization
 no login authentication
 vrf v1
 exit
!
server p4lang p4
 export-vrf v1 1
 export-port sdn1 1 0
 interconnect ethernet0
 vrf v1
 exit
!
end

Code Block

language	bash
theme	Midnight
title	Check control plane is communicating with bf_switchd p4 dataplane

p4pcap-freerouter#show interfaces summary                                          
interface  state  tx    rx      drop
ethernet0  up     8739  404545  0
sdn1       up     8535  400013  0

...

Expand

title	Connectivity IPv4/IPv6 check for freeRouter

Code Block

language	bash
theme	Midnight
title	Ping IPv4 from freerouter -> LAN router gateway

p4pcap-freerouter#ping 192.168.0.254 /vrf v1                                       
pinging 192.168.0.254, src=null, cnt=5, len=64, tim=1000, ttl=255, tos=0, sweep=false
.!!!!
result=80%, recv/sent/lost=4/5/1, rtt min/avg/max/total=1/1/2/1011

Code Block

language	bash
theme	Midnight
title	Ping IPv4 from freerouter -> LAN server

p4pcap-freerouter#ping 192.168.0.62 /vrf v1                                        
pinging 192.168.0.62, src=null, cnt=5, len=64, tim=1000, ttl=255, tos=0, sweep=false
.!!!!
result=80%, recv/sent/lost=4/5/1, rtt min/avg/max/total=1/1/2/1005

Note
Please observe the 1st ICMP packet loss that triggered \ ARP learning for respectively 192.168.0.254 and 192.168.0.62.

Code Block

language	bash
theme	Midnight
title	IPv4 arp check

p4pcap-freerouter#sh ipv4 arp sdn1                                                 
mac             address        time      static
e03f.496d.1899  192.168.0.62   00:00:57  false    <----- Host server
0024.d4a0.0cd3  192.168.0.254  00:00:57  false    <----- LAN gateway

Code Block

language	bash
theme	Midnight
title	Ping IPv6 from freerouter -> LAN router

p4pcap-freerouter#ping 2a01:e0a:159:2850::1  /vrf v1                               
pinging 2a01:e0a:159:2850::1, src=null, cnt=5, len=64, tim=1000, ttl=255, tos=0, sweep=false
.!!!!
result=80%, recv/sent/lost=4/5/1, rtt min/avg/max/total=0/1/2/1004

Code Block

language	bash
theme	Midnight
title	Ping IPv6 from freerouter -> Host server and SSH connection test

p4pcap-freerouter#ping 2a01:e0a:159:2850:e23f:49ff:fe6d:1899  /vrf v1              
pinging 2a01:e0a:159:2850:e23f:49ff:fe6d:1899, src=null, cnt=5, len=64, tim=1000, ttl=255, tos=0, sweep=false
.!!!!
result=80%, recv/sent/lost=4/5/1, rtt min/avg/max/total=1/1/1/1006

Note
Please observe the 1st ICMP packet loss that triggered IPv6 neighbor discovery for respectively 2a01:e0a:159:2850::1 and 2a01:e0a:159:2850:e23f:49ff:fe6d:1899

Code Block

language	bash
theme	Midnight
title	IPv6 neighbor discovery check

p4pcap-freerouter#show ipv6 neighbors sdn1                                         
mac             address                                time      static  router
0024.d4a0.0cd3  2a01:e0a:159:2850::1                   00:00:53  false   false
e03f.496d.1899  2a01:e0a:159:2850:e23f:49ff:fe6d:1899  00:00:53  false   false
0024.d4a0.0cd3  fe80::224:d4ff:fea0:cd3                00:00:53  false   false
e03f.496d.1899  fe80::e23f:49ff:fe6d:1899              00:00:53  false   false

Code Block

language	bash
theme	Midnight
title	Initiate IPv4 ssh from freerouter -> LAN router gateway

p4pcap-freerouter#ssh 192.168.0.62 /vrf v1 /user my-nas                           
 - connecting to 192.168.0.62 22
password: *******
                
 - securing connection

Last login: Mon Jul  6 15:05:38 2020 from 192.168.0.77
FreeBSD 11.3-RELEASE-p9 (FreeNAS.amd64) #0 r325575+588899735f7(HEAD): Mon Jun  1 15:04:31 EDT 2020

        FreeNAS (c) 2009-2020, The FreeNAS Development Team
        All rights reserved.
        FreeNAS is released under the modified BSD license.

        For more information, documentation, help or support, go here:
        http://freenas.org
Welcome to FreeNAS
MY-NAS%

Code Block

language	bash
theme	Midnight
title	Initiate IPv6 ssh from freerouter -> LAN router gateway

p4pcap-freerouter#ssh 2a01:e0a:159:2850:e23f:49ff:fe6d:1899  /vrf v1 /user my-nas 
 - connecting to 2a01:e0a:159:2850:e23f:49ff:fe6d:1899 22
password: *******
                
 - securing connection

Last login: Tue Jul  7 16:01:54 2020 from 2a01:e0a:159:2850::666
FreeBSD 11.3-RELEASE-p9 (FreeNAS.amd64) #0 r325575+588899735f7(HEAD): Mon Jun  1 15:04:31 EDT 2020

        FreeNAS (c) 2009-2020, The FreeNAS Development Team
        All rights reserved.
        FreeNAS is released under the modified BSD license.

        For more information, documentation, help or support, go here:
        http://freenas.org
Welcome to FreeNAS
MY-NAS%

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Tip

title	[ #005 ] RARE/FreeRouter-101 - key take-away

FreeRouter is using UNIX socket in order to forward packet dedicated to control plane + dataplane communication.

This essential paradigm is used to ensure communication between freeRouter and P4Emu/pcap dataplane. It is ensured by pcapInt binary from freeRouter net-tools that will bind freeRouter socket (veth251@locathost:22710) to a virtual network interface (veth250@localhost:22709) connected to CPU_PORT 64 0.

freeRouter is the control plane for P4Emu/pcap dataplane

freeRouter is doing all the control plane route computation and write/modify/remove message entry P4 entries are created/modified/removed accordingly from P4Emu/pcap tables. Although the name is P4Emu, it does not emulate BMv2 V1Model.p4, but rather router.p4

In this setup the combination of freeRouter/pcap deliver a solution for SOHO network having 1GE links

However, 1GE traffic rate require 50% of one CPU thread. Nevertheless, traffic rate achieved is higher with P4Emu/pcap than freeRouter native software packet forwarding software.

Note
In subsequent article we will see how we can improve the latter requirement implied by P4Emu/pcap.

...

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