06-03-2022
03:37 PM
- last edited on
06-04-2022
01:36 AM
by
Translator
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.
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
!
Solved! Go to Solution.
06-03-2022 03:43 PM - edited 06-03-2022 03:44 PM
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
06-03-2022 03:43 PM - edited 06-03-2022 03:44 PM
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
06-03-2022 05:05 PM
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?
06-04-2022 12:50 AM - edited 06-04-2022 01:08 AM
Because as I said with a /24 mask 100.121.1.0 is not a host address, it is the subnet address.
Jon
06-03-2022 03:59 PM
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
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