Configuration procedure

Procedure
  1. Configure IP addresses for interfaces (omitted.)
  2. Configure eBGP.
  3. # Configure Switch A.
    switch(config)# router bgp 10
    switch(bgp)# bgp router-id 1.1.1.1
    switch(bgp)# neighbor 200.1.2.2 remote-as 20
    switch(bgp)# network 9.1.1.0/255.255.255.0/8
    switch(bgp)# exit
    
    
  4. # Configure Switch B.
     
    switch(config)# bgp 20
    switch(bgp)# bgp router-id 2.2.2.2
    switch(bgp)# neighbor 200.1.2.1 remote-as 10
    switch(bgp)# neighbor 200.1.3.2 remote-as 30
    switch(bgp)# exit
    
    
  5. # Configure Switch C.
    switch(config)# bgp 30
    switch(bgp)# bgp router-id 3.3.3.3
    switch(bgp)# neighbor 200.1.3.1 remote-as 20
    switch(bgp)# exit
    
    
  6. # Display the BGP routing table on Switch B.
    switch(config)# show ip bgp 9.1.1.0
    
    Local AS : 20 Local Router-id : 2.2.2.2
    BGP Table Version  : 3
    
    Network : 9.1.1.0/24       Nexthop         : 200.1.2.1
    Peer   : 200.1.2.1        Origin          : igp 
    Metric : 0                Local Pref      : 
    Weight : 0                Calc. Local Pref : 100
    Valid  : Yes              Type            : external
    Stale  : No
    Best   : Yes (Only Route Available) 
    AS-Path : 100
    Communities :
    
    
  7. Switch B advertised routes to Switch C in AS 30.
  8. # Display the routing table on Switch C.
    switch(config)# show ip bgp
    
    Local AS : 30
    Local Router-id : 3.3.3.3
    
    BGP Table Version  : 1
    Status codes: * - valid, > - best, i - internal, e - external, s - stale
    
    Origin codes: i - IGP, e - EGP, ? - incomplete
    
    Network        Nexthop   Metric LocalPref Weight AsPath
    -------------------------------------------------------
    *>i 9.1.1.0/24 200.1.3.1      0            100     10i
    
    
  9. Switch C learned route 9.1.1.0/24 from Switch B.
  10. Configure the BGP community.
  11. # Configure a routing policy.
    route-map bgp-out permit seq 10
    switch(route-map-bgp-out)# set community no-export
    switch(route-map-bgp-out)# exit
  12. # Apply the routing policy.
    switch(config)# bgp 10
    switch(bgp)# neighbor 200.1.2.2 route-map bgp-out out
    
    
  13. # Display the route on Switch B.
    switch(config)# show ip bgp 9.1.1.0/24
    
    Local AS : 20 Local Router-id : 2.2.2.2
    BGP Table Version  : 3
    
    Network     : 9.1.1.0/24   Nexthop         : 200.1.2.1
    Peer       : 200.1.2.1    Origin          : igp Metric     : 0            Local Pref      : Weight  
       : 0            Calc. Local Pref : 100
    Valid      : Yes          Type            : external
    Stale      : No
    Best       : Yes (Only Route Available) AS-Path    : 100
    Communities: no-export
    
    # Display the routing table on Switch C.
    switch# show ip bgp 9.1.1.0/24
    
    
  14. The route 9.1.1.0/24 is not available in the routing table of Switch C.