Debian/Ubuntu Tips and Tricks

Debuntu

Debian/Ubuntu Tips and Tricks

How-To: Setting up BGP on Vyatta — page 3 — Setting BGP

Posted by chantra on November 2nd, 2008

This entry is part 3 of 3 in the series How-To: Setting up BGP on Vyatta

3. Setting BGP

As told earlier on, vyatta-bgp1 will advertise AS 1 with network 1.1.1.0/24 to its neighbor vyatta-bgp2 handling AS 2
and
vyatta-bgp2 will advertise AS 2 with network 2.2.2.0/24 to its neighbor vyatta-bgp1 handling AS 1

They will use a common password for this communication, which is BGPtutorial.

The syntax used in configuration mode is the following:

# set protocols bgp <my AS> neighbor <peer IP address> remote-as <peer AS>
# set protocols bgp <my AS> network <advertise network1>
# set protocols bgp <my AS> network <advertise network2>
....
# set protocols bgp <my AS> neighbor <peer IP address> password <bgp password>

Which on each host will give:

3.1. vyatta-bgp1

[edit]
vyatta@vyatta-bgp1# set protocols bgp 1 neighbor 172.16.163.2 remote-as 2
[edit]
vyatta@vyatta-bgp1# set protocols bgp 1 network 1.1.1.0/24
[edit]
vyatta@vyatta-bgp1# set protocols bgp 1 neighbor 172.16.163.2 password BGPtutorial
[edit]
vyatta@vyatta-bgp1# commit
[edit]
vyatta@vyatta-bgp1# save
Saving configuration to '/opt/vyatta/etc/config/config.boot'...
Done

At this stage, within a root shell on vyatta-bgp1, you should get the following result:

vyatta-bgp1:~# show ip bgp
BGP table version is 0, local router ID is 1.1.1.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale, R Removed
Origin codes: i - IGP, e - EGP, ? - incomplete
   Network          Next Hop            Metric LocPrf Weight Path
*> 1.1.1.0/24       0.0.0.0                  1         32768 i
Total number of prefixes 1

While vyatta-bgp2, which is not yet configured will display:

vyatta-bgp2:~# show ip bgp
No BGP process is configured

and the route tables will not yet be modified.

3.2. vyatta-bgp2

Similarly on vyatta-bgp2

[edit]
vyatta@vyatta-bgp2# set protocols bgp 2 neighbor 172.16.163.1 remote-as 1
[edit]
vyatta@vyatta-bgp2# set protocols bgp 2 network 2.2.2.0/24
[edit]
vyatta@vyatta-bgp2# set protocols bgp 2 neighbor 172.16.163.1 password BGPtutorial
[edit]
vyatta@vyatta-bgp2# commit
[edit]
vyatta@vyatta-bgp2# save
Saving configuration to '/opt/vyatta/etc/config/config.boot'...
Done

3.3. Confirming the settings

From there, everything should be configured, vyatta-bgp1 will show:

vyatta@vyatta-bgp1:~$ show ip bgp
BGP table version is 0, local router ID is 1.1.1.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale, R Removed
Origin codes: i - IGP, e - EGP, ? - incomplete
   Network          Next Hop            Metric LocPrf Weight Path
*> 1.1.1.0/24       0.0.0.0                  1         32768 i
*> 2.2.2.0/24       172.16.163.2             1             0 2 i
Total number of prefixes 2
vyatta@vyatta-bgp1:~$ show ip route
Codes: K - kernel route, C - connected, S - static, R - RIP, O - OSPF,
       I - ISIS, B - BGP, > - selected route, * - FIB route
S>* 0.0.0.0/0 [1/0] via 192.168.2.1, eth0
C>* 1.1.1.0/24 is directly connected, eth2
B>* 2.2.2.0/24 [20/1] via 172.16.163.2, eth1, 00:03:15
C>* 127.0.0.0/8 is directly connected, lo
C>* 172.16.163.0/24 is directly connected, eth1
C>* 192.168.2.0/24 is directly connected, eth0
vyatta@vyatta-bgp1:~$ /sbin/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
2.2.2.0         172.16.163.2    255.255.255.0   UG    1      0        0 eth1
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
vyatta@vyatta-bgp1:~$

and on the other side vyatta-bgp2 will show:

vyatta@vyatta-bgp2:~$ show ip bgp
BGP table version is 0, local router ID is 2.2.2.2
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale, R Removed
Origin codes: i - IGP, e - EGP, ? - incomplete
   Network          Next Hop            Metric LocPrf Weight Path
*> 1.1.1.0/24       172.16.163.1             1             0 1 i
*> 2.2.2.0/24       0.0.0.0                  1         32768 i
Total number of prefixes 2
vyatta@vyatta-bgp2:~$ show ip route
Codes: K - kernel route, C - connected, S - static, R - RIP, O - OSPF,
       I - ISIS, B - BGP, > - selected route, * - FIB route
S>* 0.0.0.0/0 [1/0] via 192.168.2.1, eth0
B>* 1.1.1.0/24 [20/1] via 172.16.163.1, eth1, 00:04:02
C>* 2.2.2.0/24 is directly connected, eth2
C>* 127.0.0.0/8 is directly connected, lo
C>* 172.16.163.0/24 is directly connected, eth1
C>* 192.168.2.0/24 is directly connected, eth0
vyatta@vyatta-bgp2:~$ /sbin/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         172.16.163.1    255.255.255.0   UG    1      0        0 eth1
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
vyatta@vyatta-bgp2:~$

Mind the more verbose output given by show ip route compare to route. There you can see that there is one static route (the one we created with set system gateway-address 192.168.2.1), one BGP route and 4 connected routes (the ones for each interfaces: eth{0,1,2} and lo).

Series Navigation<< How-To: Setting up BGP on Vyatta — page 2 — Network interfaces

Leave a Reply

XHTML: You can use these tags: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>