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Transit router cannot ping border router

hfakoor222
Spotlight
Spotlight

 

Tr2 cannot ping B5, same subnet directly connected  ~ show run listed below I could use some help as to why. i realise there's some commands in there that are extra and may be out of place, for now I am ok with that, however I cannot figure out why it wont ping. Just now I also realise I should reqrite my router BGP command but that is okay for now, I would like to get a ping going first.

 

2.png3.png

 

 

Transit router Command





Current configuration : 3092 bytes
!
upgrade fpd auto
version 12.4
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname TR2
!
boot-start-marker
boot-end-marker
!
logging message-counter syslog
!
no aaa new-model
ip source-route
no ip icmp rate-limit unreachable
ip cef
!
!
!
!
no ip domain lookup
ipv6 unicast-routing
ipv6 cef
!
multilink bundle-name authenticated
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
archive
log config
hidekeys
!
!
!
!
!
ip tcp synwait-time 5
!
!
!
!
interface Loopback0
description Loopback on Border
ip address 100.68.2.5 255.255.255.255
ipv6 address 2001:DB8:2::5/128
!
interface FastEthernet0/0
description Link to AS 40
ip address 100.122.1.0 255.255.255.254
shutdown
duplex half
ipv6 address 2001:18:0:11::/127
ipv6 address 2001:19:0:10::/128
!
interface FastEthernet1/0
description Link to AS 50
ip address 100.121.1.0 255.255.255.254
no ip redirects
no ip proxy-arp
duplex auto
speed auto
ipv6 address 2001:18:0:10::/127
ipv6 address 2001:19:0:11::/128
ipv6 nd prefix default no-advertise
ipv6 nd ra suppress
!
interface FastEthernet1/1
description Link to TR 2
ip address 100.121.0.0 255.255.255.254 secondary
ip address 10.10.0.235 255.255.255.0
duplex auto
speed auto
ipv6 address 2001:18::/127
ipv6 address 2001:DB8:100::235/64
!
router bgp 123
no bgp default ipv4-unicast
bgp log-neighbor-changes
bgp deterministic-med
neighbor 2001:18::1 remote-as 122
neighbor 2001:18::1 description EBG with TR2
neighbor 2001:18::1 ttl-security hops 2
neighbor 2001:18::1 password BGPlab
neighbor 2001:19:0:10::1 remote-as 40
neighbor 2001:19:0:10::1 password BGPlab
neighbor 2001:19:0:11::1 remote-as 50
neighbor 2001:19:0:11::1 password BGPlab
neighbor 100.121.0.1 remote-as 122
neighbor 100.121.0.1 description eBGP with TR2
neighbor 100.121.0.1 ttl-security hops 1
neighbor 100.121.0.1 password BGPlab
neighbor 100.121.1.1 remote-as 50
neighbor 100.121.1.1 password BGPlab
neighbor 100.122.1.1 remote-as 40
!
address-family ipv4
neighbor 100.121.1.1 activate
neighbor 100.121.1.1 default-originate
neighbor 100.122.1.1 activate
neighbor 100.122.1.1 default-originate
distance bgp 200 200 200
no auto-summary
no synchronization
network 100.121.0.0 mask 255.255.0.0
network 100.122.0.0 mask 255.255.0.0
exit-address-family
!
address-family ipv6
neighbor 2001:19:0:10::1 activate
neighbor 2001:19:0:10::1 default-originate
neighbor 2001:19:0:11::1 activate
neighbor 2001:19:0:11::1 default-originate
distance bgp 200 200 200
network 2001:19::/32
exit-address-family
!
ip forward-protocol nd
ip route 0.0.0.0 0.0.0.0 10.10.0.254
ip route 100.121.0.0 255.255.0.0 Null0
no ip http server
no ip http secure-server
!
!
!
no cdp log mismatch duplex
ipv6 route 2001:19::/32 Null0
ipv6 route ::/0 2001:DB8:100::241
!
!
!
!
!
!
control-plane
!
!
!
!
!
!
!
gatekeeper
shutdown
!
!
line con 0
exec-timeout 0 0
privilege level 15
logging synchronous
stopbits 1
line aux 0
exec-timeout 0 0
privilege level 15
logging synchronous
stopbits 1
line vty 0 4
login
!
end




























Border Router  B5


key chain as50-key
key 1
key-string 7 030D481B0A0E23
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
archive
log config
hidekeys
!
!
!
!
!
ip tcp synwait-time 5
ip tcp path-mtu-discovery
!
!
!
!
interface Loopback0
description Loopback int
ip address 100.68.5.1 255.255.255.255
ipv6 address 2001:DB8:5::1/128
!
interface Null0
no ip unreachables
no ipv6 unreachables
!
interface FastEthernet0/0
no ip address
shutdown
duplex half
!
interface FastEthernet1/0
ip address 100.121.1.1 255.255.255.0
duplex auto
speed auto
ipv6 address 2001:19:0:11::1/127
!
interface FastEthernet1/1
description BackBone link to Core
ip address 100.68.5.17 255.255.255.254
no ip redirects
no ip proxy-arp
ip router isis as50
duplex auto
speed auto
ipv6 address 2001:DB8:5:10::1/127
ipv6 nd prefix default no-advertise
ipv6 nd ra suppress
ipv6 router isis as50
isis network point-to-point
isis metric 2
isis ipv6 metric 2
!
router isis as50
net 49.0001.0005.0001.00
is-type level-2-only
metric-style wide
set-overload-bit on-startup wait-for-bgp
log-adjacency-changes all
metric 100000
passive-interface Loopback0
!
address-family ipv6
set-overload-bit on-startup wait-for-bgp
exit-address-family
!
router bgp 50
no bgp default ipv4-unicast
bgp log-neighbor-changes
bgp deterministic-med
neighbor ibgp-rr peer-group
neighbor ibgp-rr remote-as 50
neighbor ibgp-rr description iBGP with RR
neighbor ibgp-rr password 7 072D067C42081B
neighbor ibgp-rr update-source Loopback0
neighbor ibgpv6-rr peer-group
neighbor ibgpv6-rr remote-as 50
neighbor ibgpv6-rr description iBGP with RR
neighbor ibgpv6-rr password 7 13273022070D06
neighbor ibgpv6-rr update-source Loopback0
neighbor 2001:DB8:5::2 peer-group ibgpv6-rr
neighbor 2001:DB8:5::2 description iBGP with Core
neighbor 100.68.3.2 peer-group ibgp-rr
neighbor 100.68.3.2 description iBGP with Core
neighbor 100.68.5.2 peer-group ibgp-rr
neighbor 100.68.5.2 description iBGP with Core
!
address-family ipv4
neighbor ibgp-rr send-community
neighbor ibgp-rr next-hop-self
neighbor 100.68.3.2 activate
neighbor 100.68.5.2 activate
distance bgp 200 200 200
no auto-summary
no synchronization
exit-address-family
!
address-family ipv6
neighbor ibgpv6-rr send-community
neighbor ibgpv6-rr next-hop-self
neighbor 2001:DB8:5::2 activate
distance bgp 200 200 200
network 2001:DB8:5::/48
exit-address-family
!
ip forward-protocol nd
no ip http server
no ip http secure-server
!
!
!
no cdp log mismatch duplex
!
!
!
!
!
!
control-plane
!
!
!
!
!
!
!
gatekeeper
shutdown
!
!
line con 0
exec-timeout 0 0
privilege level 15
logging synchronous
transport preferred none
stopbits 1
line aux 0
exec-timeout 0 0
privilege level 15
logging synchronous
transport preferred none
stopbits 1
line vty 0 4
transport preferred none
!









1 Accepted Solution

Accepted Solutions

Jon Marshall
Hall of Fame
Hall of Fame

 

I don't have anything to test with but I suspect it is because you are using a /24 subnet mask on B5 which means the subnet address is 100.121.1.0 but that is the IP on TR2. 

 

Either change the subnet mask on TR2 eg. a /30 or greater should do it or change the subnet mask on B5 to be /31. 

 

Jon

View solution in original post

4 Replies 4

Jon Marshall
Hall of Fame
Hall of Fame

 

I don't have anything to test with but I suspect it is because you are using a /24 subnet mask on B5 which means the subnet address is 100.121.1.0 but that is the IP on TR2. 

 

Either change the subnet mask on TR2 eg. a /30 or greater should do it or change the subnet mask on B5 to be /31. 

 

Jon

changing the mask on B5 from /24 to/31

 

 

ip add 100.121.1.1 255.255.255.254 worked

 

and 255.255.255.252 did not seem to work

Can someone explain this to me why the /31 mask worked and not the /24 mask?

 

Because as I said with a /24 mask 100.121.1.0 is not a host address, it is the subnet address. 

 

Jon

Jon Marshall
Hall of Fame
Hall of Fame

 

Should have also said if you change the subnet mask on TR2 then you also need to change the IP to use a valid IP from whatever subnet you choose. 

 

Jon