Debuntu

2. Setting the network interfaces

During this part, we are going to set up the 2 Border Gateway routers’network interfaces. In vyatta world, you need to enter the interactive configuration shell by typing:

vyatta@vyatta-bgp1:~$ configure
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vyatta@vyatta-bgp1#

2.1. vyatta-bgp1

Once you are in edition mode, type the following to set up eth0, eth1 and eth2:

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vyatta@vyatta-bgp1# set interfaces ethernet eth0 address 192.168.2.10/24
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vyatta@vyatta-bgp1# set interfaces ethernet eth1 address 172.16.163.1/24
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vyatta@vyatta-bgp1# set interfaces ethernet eth2 address 1.1.1.1/24

Then, set up the default route to be 192.168.2.1:

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vyatta@vyatta-bgp1# set system gateway-address 192.168.2.1

and optionally you can set the DNS server to query:

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vyatta@vyatta-bgp1# set system name-server 192.168.2

and finally commit and save so the setting stays upon reboot:

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vyatta@vyatta-bgp1# commit
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vyatta@vyatta-bgp1# save
Saving configuration to ‘/opt/vyatta/etc/config/config.boot’…
Done

2.2. vyatta-bgp2

On vyatta-bgp2, the settings are similar except that we have to change some addressing. Here is the resulting command line serie:

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vyatta@vyatta-bgp2# set interfaces ethernet eth0 address 192.168.2.20/24
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vyatta@vyatta-bgp2# set interfaces ethernet eth1 address 172.16.163.2/24
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vyatta@vyatta-bgp2# set interfaces ethernet eth2 address 2.2.2.2/24
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vyatta@vyatta-bgp2# set system gateway-address 192.168.2.1
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vyatta@vyatta-bgp2# set system name-server 192.168.2.1
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vyatta@vyatta-bgp2# commit
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vyatta@vyatta-bgp2# save
Saving configuration to ‘/opt/vyatta/etc/config/config.boot’…
Done

2.3. Resulting routes

At this stage, the route table on vyatta-bgp1 looks like:

vyatta-bgp1:~# route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         192.168.2.1     0.0.0.0         UG    0      0        0 eth0
1.1.1.0         0.0.0.0         255.255.255.0   U     0      0        0 eth2
172.16.163.0    0.0.0.0         255.255.255.0   U     0      0        0 eth1
192.168.2.0     0.0.0.0         255.255.255.0   U     0      0        0 eth0

and on vyatta-bgp2:

vyatta414-tpl:~# route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         192.168.2.1     0.0.0.0         UG    0      0        0 eth0
2.2.2.0         0.0.0.0         255.255.255.0   U     0      0        0 eth2
172.16.163.0    0.0.0.0         255.255.255.0   U     0      0        0 eth1
192.168.2.0     0.0.0.0         255.255.255.0   U     0      0        0 eth0

And thus, the default gateway of vyatta-bgp1 and vyatta-bgp2 will be used when attempting to contact respectively 2.2.2.0/24 and 1.1.1.0/24.

We now need to set up BGP on those 2 servers to advertise new routes to each others.