11.2.1 Packet Tracer - Configure and Verify eBGP (Answers)

ACME1(config)# router bgp 65001
ACME1(config-router)# neighbor 1.1.1.1 remote-as 65003
ACME1(config-router)# network 192.168.0.0 mask 255.255.255.0

OtherCo1(config)# router bgp 65002
OtherCo1(config-router)# neighbor 1.1.1.9 remote-as 65003
OtherCo1(config-router)# network 172.16.10.0 mask 255.255.255.0

! ==============================================================
!--- 11.2.1 Packet Tracer - Configure and Verify eBGP
!--- ANSWER SCRIPT FOR ROUTER ACME1 (AS 65001)
!--- Usage: copy this whole file and paste it into the ACME1 terminal (start at the ACME1> prompt). Every line beginning with "!" is a comment; IOS ignores it, so pasting a comment by accident is harmless.
!--- Scope: IP addressing is already configured, and the ISP's transit
!--- AS (65003) already has full internal reachability, per the
!--- activity's own Background note - this script only stands up the
!--- eBGP peering from ACME's side.
! ==============================================================

enable
configure terminal

! --------------------------------------------------------------
!--- Part 1, Step c: Peer with the ISP's border router (ISP-Entry-1)
!--- over eBGP and advertise ACME's internal network.
! --------------------------------------------------------------

router bgp 65001

!--- ISP-Entry-1's S0/0/0 address, directly connected to ACME1 - the
!--- differing AS number (65003 vs ACME's own 65001) is what makes
!--- this an eBGP session rather than iBGP.
 neighbor 1.1.1.1 remote-as 65003

!--- Advertise the ACME LAN so Other Company (and the ISP) can route to it.
!--- The mask here must exactly match what's configured on G0/0 (/24),
!--- or BGP won't find a matching connected/static route to advertise.
 network 192.168.0.0 mask 255.255.255.0
 exit

end

! --------------------------------------------------------------
!--- Save the configuration to NVRAM. (Press Enter when prompted for the destination filename.)
! --------------------------------------------------------------
copy running-config startup-config


! ==============================================================
!--- Verification:
!---   show ip bgp summary   -> neighbor 1.1.1.1, state up, AS 65003
!---   show ip route bgp     -> B 172.16.10.0/24 [20/0] via 1.1.1.1  (only after OtherCo1's script also runs)
!---   ping 172.16.10.2       -> Other Company's server, only works once OtherCo1 is also configured
!--- Note: pinging the Other Company server will still fail after this
!--- script alone - OtherCo1 hasn't advertised its network yet, so
!--- ACME1 has no route back. This matches the lab's own Part 1 ending
!--- ("Does it work? No.") - full connectivity needs the companion
!--- OtherCo1 script as well.
! ==============================================================

! ==============================================================
!--- 11.2.1 Packet Tracer - Configure and Verify eBGP
!--- ANSWER SCRIPT FOR ROUTER OTHERCO1 (AS 65002)
!--- Usage: copy this whole file and paste it into the OtherCo1 terminal (start at the OtherCo1> prompt). Every line beginning with "!" is a comment; IOS ignores it, so pasting a comment by accident is harmless.
!--- Scope: IP addressing is already configured, and the ISP's transit
!--- AS (65003) already has full internal reachability, per the
!--- activity's own Background note - this script only stands up the
!--- eBGP peering from Other Company's side.
! ==============================================================

enable
configure terminal

! --------------------------------------------------------------
!--- Part 2: Peer with the ISP's border router (ISP-Entry-2) over eBGP
!--- and advertise Other Company's internal network.
! --------------------------------------------------------------

router bgp 65002

!--- ISP-Entry-2's S0/0/0 address, directly connected to OtherCo1 - the
!--- differing AS number (65003 vs Other Company's own 65002) is what
!--- makes this an eBGP session rather than iBGP.
 neighbor 1.1.1.9 remote-as 65003

!--- Advertise the Other Company LAN so ACME (and the ISP) can route to it.
!--- The mask here must exactly match what's configured on G0/0 (/24),
!--- or BGP won't find a matching connected/static route to advertise.
 network 172.16.10.0 mask 255.255.255.0
 exit

end

! --------------------------------------------------------------
!--- Save the configuration to NVRAM. (Press Enter when prompted for the destination filename.)
! --------------------------------------------------------------
copy running-config startup-config


! ==============================================================
!--- Verification:
!---   show ip bgp summary   -> neighbor 1.1.1.9, state up, AS 65003
!---   show ip route bgp     -> B 192.168.0.0/24 [20/0] via 1.1.1.9
!---   ping 192.168.0.x       -> any ACME end device, once both sides are configured
!--- Note: the lab's own Address Table lists this router's LAN
!--- interface as "G/0/0" (with a stray slash) - it's the same interface
!--- as ACME1's G0/0, just a typo in the published table; doesn't affect
!--- this script since BGP's "network" command only needs the address
!--- and mask, not the interface name.
! ==============================================================