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  • all people connected within 192.168.128.0/17
  • to access the external world.

First step, let's:

  • create an interface Loopback0 within 192.168.128.0/17, let's say 192.168.254.1/32
  • and try to ping 8.8.8.8

Article objective

In this article we will pursue the SOHO network appliance installation and enable IPv4 connectivity for all host connected within your internal network to the external world.

Diagrams

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#004 ] -

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 Do you need translation ? 

Expand
titleCreate router loopback in VRF inet

First step, let's create an interface Loopback0 within 192.168.128.0/17, let's say 192.168.254.1/32

Code Block
languagebash
themeMidnight
titleSOHO router in VRF inet
sh run loopback0                                                        
interface loopback0
 no description
 vrf forwarding inet
 ipv4 address 192.168.254.1 255.255.255.255
 no shutdown
 no log-link-change
 exit
!


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Expand
titleFirst troubleshooting action


Code Block
languagebash
themeMidnight
titletraceroute 8.8.8.8 using looback0 as source address
traceroute 8.8.8.8 /vrf inet /interface lo0                            
tracing 8.8.8.8, src=192.168.254.1, vrf=inet, prt=0/33440, tim=1000, tos=0, len=64
1 192.168.254.1 time=0
2 null time=1000
3 null time=1000
4 null time=1000
5 null time=1000
6 null time=1000
7 null time=1000
8 null time=1000
9 null time=1000
10 null time=1000

This confirms the ping failures we observed previously. The output above indicate the packet does not even egress our SOHO router.

What is the inet VRF says ?

Code Block
languagebash
themeMidnight
titleroutes inside VRF inet
show ipv4 route inet                                                   
typ  prefix            metric  iface      hop            time
C    192.168.0.0/24    0/0     sdn1       null           14:30:07
LOC  192.168.0.90/32   0/1     sdn1       null           14:30:07
C    192.168.128.0/24  0/0     sdn999     null           14:30:13
LOC  192.168.128.1/32  0/1     sdn999     null           14:30:13
C    192.168.254.1/32  0/0     loopback0  null           14:30:15

So we have no default routes . Let's configure one then pointing towards ISP BOX gateway:

Code Block
languagebash
themeMidnight
titleDefault route configuration
conf t
ipv4 route inet 0.0.0.0 0.0.0.0 192.168.0.254


Code Block
languagebash
themeMidnight
titleroutes inside VRF inet
show ipv4 route inet                                                   
typ  prefix            metric  iface      hop            time
S    0.0.0.0/0         1/0     sdn1       192.168.0.254  14:30:07
C    192.168.0.0/24    0/0     sdn1       null           14:30:07
LOC  192.168.0.90/32   0/1     sdn1       null           14:30:07
C    192.168.128.0/24  0/0     sdn999     null           14:30:13
LOC  192.168.128.1/32  0/1     sdn999     null           14:30:13
C    192.168.254.1/32  0/0     loopback0  null           14:30:15

So at that point, packet send to 8.8.8.8 are sent to nexthop 192.168.0.254 via sdn1.

Code Block
languagebash
themeMidnight
titleping 8.8.8.8
ping 8.8.8.8 /vrf inet /interface lo0                                  
pinging 8.8.8.8, src=192.168.254.1, vrf=inet, cnt=5, len=64, tim=1000, ttl=255, tos=0, sweep=false
.....
result=0%, recv/sent/lost=0/5/5, rtt min/avg/max/total=10000/0/0/5003

But ping is still not not working. Let's figure out what's going on here.


Expand
titleNetwroking Networking environment assumption

As depicted in previous article:

  • ISP box has a demarcation point set to 192.168.0.254
  • So ISP box at some point is configured to perform Network Address Translation from 192.168.0.0/24 → ISP public IPv4 interface
  • When ISP box receives a ICMP ping from 192.168.254.1 which does not match any ISP box NAT rules → Packet is discarded

Therefore in order to have a working seamless networking environment from the ISP box point of view, traffic coming from 192.168.128.0/17 might need to be NAT(ed) into 192.168.0.0/24 network. Let's see If our guess is right.

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Tip
titleRARE validated design: [ SOHO #004 ] - key take-away

In this example we are proposing a basic connectivity scenario. However, keep in mind that depending on your location the configuration might be drastically different. But do not fear ! RARE/freeRouter has all the features need to enable connectivity !

  • NAT64 is available. So in case you want to run a pure IPv6 network, freeRouter can NAT64 traffif traffic for you.
  • NAT46 is also available. In case you are desperate and don't want to implement a pure IPv6 home network and have an ISP running only IPv6, freeRouter can NAT46 your traffic for you !
  • In the example described, we are lucky to have IPv6 public global IPv6 address. We will see IPv6 configuration in subsequent articles.

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