BGP Peer are not pinging

[Haider Raza]

Hi,

I created topology in gns3 and running BGP and router R1 is able to ping R3 and R5 but not able to ping R4 fa0/0 interface .neighbor-ship established and all interfaces are configured correctly.

Please help me to get the reason.

[Mark Malone]

Hi
wheres the configs to check the issue

[Haider Raza · Accepted solution]

R1 Config

interface Loopback100

ip address 10.5.1.1 255.255.0.0

!

interface FastEthernet0/0

ip address 10.2.1.1 255.255.255.0

duplex auto

speed auto

!

interface FastEthernet0/1

ip address 10.1.1.1 255.255.255.0

duplex auto

speed auto

!

router bgp 100

no synchronization

bgp log-neighbor-changes

network 10.1.1.0 mask 255.255.255.0

network 10.2.1.0 mask 255.255.255.0

network 172.16.1.0 mask 255.255.255.0

network 172.17.1.0 mask 255.255.255.0

neighbor 10.1.1.2 remote-as 100

neighbor 10.2.1.2 remote-as 100

no auto-summary

================================================================

R2 Config

interface FastEthernet0/0

ip address 172.16.1.1 255.255.255.0

duplex auto

speed auto

!

interface FastEthernet0/1

ip address 10.1.1.2 255.255.255.0

duplex auto

speed auto

!

router bgp 100

no synchronization

bgp log-neighbor-changes

network 10.1.1.0 mask 255.255.255.0

network 10.2.1.0 mask 255.255.255.0

network 172.16.1.0 mask 255.255.255.0

network 172.17.1.0 mask 255.255.255.0

neighbor 10.1.1.1 remote-as 100

neighbor 172.16.1.2 remote-as 900

no auto-summary

============================================================

R3 Config

interface FastEthernet0/0

ip address 172.16.1.2 255.255.255.0

duplex auto

speed auto

!

interface FastEthernet0/1

ip address 192.168.1.1 255.255.255.0

duplex auto

speed auto

!

router bgp 900

no synchronization

bgp log-neighbor-changes

network 10.1.1.0 mask 255.255.255.0

network 10.2.1.0 mask 255.255.255.0

network 172.16.1.0 mask 255.255.255.0

network 172.17.1.0 mask 255.255.255.0

network 192.168.1.0

neighbor 172.16.1.1 remote-as 100

neighbor 192.168.1.2 remote-as 900

no auto-summary

==================================================================

R4 Config

interface FastEthernet0/0

ip address 192.168.1.2 255.255.255.0

duplex auto

speed auto

!

interface FastEthernet0/1

ip address 172.17.1.2 255.255.255.0

duplex auto

speed auto

!

router bgp 900

synchronization

bgp log-neighbor-changes

network 192.168.1.0

neighbor 172.17.1.1 remote-as 100

neighbor 192.168.1.1 remote-as 900

no auto-summary

[Julio E. Moisa]

Hi

R4 should have:

neighbor 192.168.1.1 next-hop-self

The same for R5

[Mark Malone]

there needs to be static routing or IGP configuration for that subnet, BGP is not a routing protocol its a transport protocol it needs and IGP or at least static routing to route traffic , the f0/0 is an internal ip not ebgp so it needs to be advertised by IGP into BGP so it can be reachable to the other ASs that's why you cant reach it

[Julio E. Moisa]

Hi

Do you have a valid entry for R4'networks into the routing table on R1 and vice versa? or have you included the command: next-hop-self on R4 and R5?

Is possible to share the configuration of each device and the show ip route or show bgp outputs?

:-)

[paul driver]

Hello

In addition to the other  posts - Possibly also suggest

As RTR1 is an IBGP peer to RTR2/3 - Make RTRs 2 -3 the next-hop for R1 as by default ebgp prefixes with be advertised to rtr 1 with the ip address of the originator rtr and if you dont have any IGP for those networks then connectivity it will fail and this will be applicable the the ibgp rtrs on the other side also.

Example:ibgp for

RTR2/RTR3

Neighbor  <rtr1> next hop-self

res
Paul

[Haider Raza]

Hi Team,
We are getting below massage while configuring the secondary IP address on vlan interface, please suggest what it means of this message.Thanks.!