Solved: R1 cannot ping r4 yet BGP routes are propegated

hfakoor222 · ‎04-01-2022

R2:

R2 can ping R4 as it is direct connected

R2#ping 24.0.0.4

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 24.0.0.4, timeout is 2 seconds:
!!!!!

R1 cannot Pinfg R4




ype escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 24.0.0.4, timeout is 2 seconds:
.....
Success rate is 0 percent (0/5)

R1#

Configs:

hostname R1

no ip domain lookup

interface Serial0/0
ip address 10.1.12.1 255.255.255.0
clock rate 2000000
!
!
interface Serial1/0
ip address 10.1.13.1 255.255.255.0
serial restart-delay 0
!
!
router ospf 1
router-id 1.1.1.1
log-adjacency-changes
network 1.1.1.1 0.0.0.0 area 0
network 10.1.12.1 0.0.0.0 area 0
network 10.1.13.1 0.0.0.0 area 0
!
router bgp 100
bgp router-id 1.1.1.1
bgp log-neighbor-changes
neighbor 2.2.2.2 remote-as 100
neighbor 3.3.3.3 remote-as 100
neighbor 10.1.12.2 remote-as 100
neighbor 10.1.13.3 remote-as 100
!
address-family ipv4
neighbor 2.2.2.2 activate
neighbor 3.3.3.3 activate
neighbor 10.1.12.2 activate
neighbor 10.1.13.3 activate
no auto-summary
no synchronization
network 10.1.12.0 mask 255.255.255.0
network 10.1.13.0 mask 255.255.255.0
exit-address-family

Router 2







!
interface Serial0/0
ip address 10.1.12.2 255.255.255.0
clock rate 2000000
!
interface Serial1/1
ip address 10.1.23.2 255.255.255.0
serial restart-delay 0
!
interface Serial1/2
ip address 24.0.0.2 255.255.255.0
serial restart-delay 0
!
interface Serial1/3
no ip address
shutdown
serial restart-delay 0
!
router bgp 100
bgp router-id 2.2.2.2
bgp log-neighbor-changes
neighbor 1.1.1.1 remote-as 100
neighbor 3.3.3.3 remote-as 100
neighbor 4.4.4.4 remote-as 400
neighbor 4.4.4.4 ebgp-multihop 2
neighbor 10.1.12.1 remote-as 100
neighbor 10.1.23.3 remote-as 100
neighbor 24.0.0.4 remote-as 400
neighbor 24.0.0.4 ebgp-multihop 2
!
address-family ipv4
neighbor 1.1.1.1 activate
neighbor 1.1.1.1 next-hop-self
neighbor 3.3.3.3 activate
neighbor 4.4.4.4 activate
neighbor 10.1.12.1 activate
neighbor 10.1.23.3 activate
neighbor 24.0.0.4 activate
no auto-summary
no synchronization
network 10.1.23.0 mask 255.255.25.0
exit-address-family








































Router 4





speed auto
!
interface Serial0/0
ip address 24.0.0.4 255.255.255.0
clock rate 2000000
!

!
interface Serial1/0
ip address 46.0.0.4 255.255.255.0
serial restart-delay 0

!
router bgp 400
bgp router-id 4.4.4.4
bgp log-neighbor-changes
neighbor 6.6.6.6 remote-as 600
neighbor 24.0.0.2 remote-as 100
neighbor 46.0.0.6 remote-as 600
!
address-family ipv4
redistribute connected
neighbor 6.6.6.6 activate
neighbor 24.0.0.2 activate
neighbor 46.0.0.6 activate
no auto-summary
no synchronization
network 24.0.0.0 mask 255.255.255.0
network 46.0.0.0 mask 255.255.255.0
exit-address-family
!

line con 0
exec-timeout 0 0
privilege level 15
logging synchronous
line aux 0
exec-timeout 0 0
privilege level 15
logging synchronous
line vty 0 4
login

any suggestions?

paul driver · ‎04-02-2022

Hello

R2
router bgp 100
neighbor 10.1.12.1 next-hop-self
neighbor 10.1.23.3 next-hop-self

Clear ip bgp * soft in
Clear ip bgp * soft out

Please rate and mark as an accepted solution if you have found any of the information provided useful.
This then could assist others on these forums to find a valuable answer and broadens the community’s global network.

Kind Regards
Paul

View solution in original post

MHM Cisco World · ‎04-02-2022

Simply R1 not know next-hop 24.0.0.2
1-config static route for only 240.0.0.2 toward R2
2-config IGP and advertise link between Router only
3- config R2 as @paul driver  suggest to use next-hop self

paul driver · ‎04-02-2022

Hello

R2
router bgp 100
neighbor 10.1.12.1 next-hop-self
neighbor 10.1.23.3 next-hop-self

Clear ip bgp * soft in
Clear ip bgp * soft out

Please rate and mark as an accepted solution if you have found any of the information provided useful.
This then could assist others on these forums to find a valuable answer and broadens the community’s global network.

Kind Regards
Paul

hfakoor222 · ‎04-02-2022

It works

hfakoor222 · ‎04-02-2022

I have another issue

I cannot get R2 to ping R6

 R4#  sh running-conf

 router bgp 400
bgp router-id 4.4.4.4
bgp log-neighbor-changes
neighbor 6.6.6.6 remote-as 600
neighbor 24.0.0.2 remote-as 100
neighbor 46.0.0.6 remote-as 600
!
address-family ipv4
redistribute connected
neighbor 6.6.6.6 activate
neighbor 24.0.0.2 activate
neighbor 24.0.0.2 next-hop-self
neighbor 46.0.0.6 activate
neighbor 46.0.0.6 next-hop-self
no auto-summary
no synchronization
network 24.0.0.0 mask 255.255.255.0
network 46.0.0.0 mask 255.255.255.0
exit-address-family


!
interface Serial0/0
ip address 24.0.0.4 255.255.255.0
clock rate 2000000
!





interface Serial1/0
ip address 46.0.0.4 255.255.255.0
serial restart-delay 0
!

R4 has AS 100 routes in BGP routing table

yet R6 does not

R6 Configuration:


interface Loopback0
ip address 6.0.0.0 255.255.255.255
!
interface Loopback1
ip address 6.0.1.0 255.255.255.255
!
interface Loopback2
ip address 6.0.2.0 255.255.255.255
!

interface Serial0/0
ip address 67.0.0.6 255.255.255.0
clock rate 2000000

interface Serial1/0
ip address 46.0.0.6 255.255.255.0
serial restart-delay 0

!
router bgp 600
bgp router-id 6.6.6.6
bgp log-neighbor-changes
neighbor 46.0.0.4 remote-as 400
neighbor 46.0.0.4 update-source Loopback0
neighbor 67.0.0.7 remote-as 700
!
address-family ipv4
neighbor 46.0.0.4 activate
neighbor 67.0.0.7 activate
no auto-summary
no synchronization
network 6.0.0.0 mask 255.255.255.0
network 6.0.1.0 mask 255.255.255.0
network 6.0.2.0 mask 255.255.255.0
exit-address-family
!
ip forward-protocol nd
!

& R2

Has 46.0.0.0 network in its BGP routing table

In this situation am I supposed to create a static route from r4 to r6?

Would someone show me how?

This seems like a lot of nuance if someone were to be working with BGP in the field to keep a track of all of this

MHM Cisco World · ‎04-02-2022

router bgp 400
bgp router-id 4.4.4.4
bgp log-neighbor-changes
neighbor 6.6.6.6 remote-as 600
neighbor 24.0.0.2 remote-as 100
neighbor 46.0.0.6 remote-as 600

Two peer same AS 600 and I think it same peer?

And as i mention before,

Between bgp peer

Static route "only for loopback"

Igp "only link between routers and loopback"

Next hop only between ibgp

hfakoor222 · ‎04-02-2022

I created a static route to the 46.0.0.0 network from R2 and cannot still ping 46.0.0.6 at Router R6

interface Serial1/1
ip address 10.1.23.2 255.255.255.0
serial restart-delay

router bgp 100
bgp router-id 2.2.2.2
bgp log-neighbor-changes
neighbor 10.1.12.1 remote-as 100
neighbor 10.1.23.3 remote-as 100
neighbor 24.0.0.4 remote-as 400
neighbor 24.0.0.4 ebgp-multihop 2
!
address-family ipv4
neighbor 10.1.12.1 activate
neighbor 10.1.12.1 next-hop-self
neighbor 10.1.23.3 activate
neighbor 10.1.23.3 next-hop-self
neighbor 24.0.0.4 activate
no auto-summary
no synchronization
network 10.1.23.0 mask 255.255.255.0
exit-address-family
!
ip forward-protocol nd
ip route 46.0.0.0 255.255.255.0 24.0.0.4
!

any suggestions on moving forward?

MHM Cisco World · ‎04-02-2022

can you share the config of R1,R2,R4,R6.

MHM Cisco World · ‎04-02-2022

Friend I will make it easy for you
you topology divide it in two layer
first layer is contain
link between Router & Loopback "only loopback use for update-source of BGP"
you must see all link and loopback from any router in this layer EXCEPT in iBGP in which you can use next-hop self.

second layer
config the BGP and advertise all network loopback "not use for update-srouce of BGP"

what make route appear but not ping ??
do show ip bgp

see this route what it is next-hop <<<< are this next-hop reach via layer one
How I check layer one ? do show ip route any subnet not "learn form BGP 'B'" is use for layer one.
if yes then you can ping
if not then you need to reconfig layer one to make next-hop reachable.

How I do last point ??

1- using static route
2-IGP
3- next-hop self "between iBGP only"<<< how next-hop effect layer one ?? it change the next-hop to one appear in layer one