04-12-2010 03:57 AM - edited 03-06-2019 10:34 AM
I've got a strange problem. Here is the set up below:
6500 running OSPF and switching at site A
6500 running OSPF and switching at site B
3750 L3 switch running OSPF at site C
Router A and B have both an OSPF connection and a L2 trunk running between them (this is needed as there's lots of legacy stuff still running on common vlans). This seems to work fine and clients on site B are able to reach everything.
However, added new router C through OSPF to router B. Clients on Router B are then unable to reach anything on vlan X (a common vlan). Take the router C out of the equation and everything works again.
How can just adding a new network in to OSPF cause this? I would have thought if it's a routing/bridging conflict it would be happening all the time.
Any ideas?
04-12-2010 04:05 AM
You may have a classfull boundry issue or a duplicate IP subnet.
Can you provide config/remove sensitive information.
04-12-2010 06:31 AM
Here is the router C config
version 12.2
no service pad
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname Router C
!
boot-start-marker
boot-end-marker
!
logging buffered 16384
enable secret
enable password
!
username admin password
no aaa new-model
clock summer-time BST recurring last Sun Mar 2:00 last Sun Oct 2:00
switch 1 provision ws-c3750e-24pd
switch 2 provision ws-c3750e-24pd
system mtu routing 1500
vtp domain XXX
vtp mode transparent
udld aggressive
ip subnet-zero
no ip source-route
ip routing
no ip domain-lookup
ip domain-name
ip name-server x.x.x.x
ip name-server x.x.x.x
!
!
ip multicast-routing distributed
ip igmp ssm-map enable
no ip igmp ssm-map query dns
!
mls qos map cos-dscp 0 8 16 24 32 46 48 56
mls qos
!
crypto pki trustpoint TP-self-signed-3418629120
enrollment selfsigned
subject-name cn=IOS-Self-Signed-Certificate-3418629120
revocation-check none
rsakeypair TP-self-signed-3418629120
!
!
!
!
!
errdisable recovery cause udld
errdisable recovery cause link-flap
errdisable recovery interval 60
port-channel load-balance src-dst-ip
!
!
!
spanning-tree mode rapid-pvst
spanning-tree loopguard default
spanning-tree etherchannel guard misconfig
spanning-tree extend system-id
spanning-tree vlan 1-19 priority 4096
!
vlan internal allocation policy ascending
!
vlan 102
name X
!
vlan 103
name X
!
vlan 104
name X
!
vlan 105
name X
!
vlan 106
name X
!
vlan 107
name X
!
vlan 108
name X
!
vlan 109
name X
!
vlan 110
name X
!
vlan 111
name X
!
vlan 112
name X
!
vlan 113
name X
!
vlan 114
name X
!
vlan 115
name X
!
vlan 116
name X
!
vlan 117
name X
!
vlan 118
name X
!
vlan 119
name X
!
vlan 254
name X
!
ip ftp username
ip ftp password X
!
!
!
interface Loopback0
ip address x.x.x.x 255.255.255.255
!
interface Port-channel1
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 1-19,254
switchport mode trunk
!
interface Port-channel2
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 1-19,254
switchport mode trunk
!
interface Port-channel3
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 1-19,254
switchport mode trunk
!
interface Port-channel4
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 1-19,254
switchport mode trunk
!
interface Port-channel5
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 1-19,254
switchport mode trunk
!
interface Port-channel6
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 1-19,254
switchport mode trunk
!
interface Port-channel48
no switchport
ip address x.x.x.x 255.255.255.0
no ip redirects
no ip unreachables
no ip proxy-arp
ip pim sparse-mode
ip ospf message-digest-key 2 md5
mls qos trust dscp
no shut
end
!
interface FastEthernet0
no ip address
no ip route-cache cef
no ip route-cache
no ip mroute-cache
shutdown
!
interface GigabitEthernet1/0/1
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 1-19,254
switchport mode trunk
srr-queue bandwidth share 10 10 60 20
queue-set 2
priority-queue out
mls qos trust dscp
channel-group 1 mode active
!
interface GigabitEthernet1/0/2
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 1-19,254
switchport mode trunk
srr-queue bandwidth share 10 10 60 20
queue-set 2
priority-queue out
mls qos trust dscp
channel-group 2 mode active
!
interface GigabitEthernet1/0/3
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 1-19,254
switchport mode trunk
srr-queue bandwidth share 10 10 60 20
queue-set 2
priority-queue out
mls qos trust dscp
channel-group 3 mode active
!
interface GigabitEthernet1/0/4
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 1-19,254
switchport mode trunk
srr-queue bandwidth share 10 10 60 20
queue-set 2
priority-queue out
mls qos trust dscp
channel-group 4 mode active
!
interface GigabitEthernet1/0/5
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 1-19,254
switchport mode trunk
srr-queue bandwidth share 10 10 60 20
queue-set 2
priority-queue out
mls qos trust dscp
channel-group 5 mode active
!
interface GigabitEthernet1/0/6
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 1-19,254
switchport mode trunk
srr-queue bandwidth share 10 10 60 20
queue-set 2
priority-queue out
mls qos trust dscp
channel-group 6 mode active
!
interface GigabitEthernet1/0/7
!
interface GigabitEthernet1/0/8
!
interface GigabitEthernet1/0/9
!
interface GigabitEthernet1/0/10
!
interface GigabitEthernet1/0/11
!
interface GigabitEthernet1/0/12
!
interface GigabitEthernet1/0/13
!
interface GigabitEthernet1/0/14
!
interface GigabitEthernet1/0/15
switchport access vlan 111
switchport mode access
spanning-tree portfast
spanning-tree bpduguard enable
!
interface GigabitEthernet1/0/16
switchport access vlan 111
switchport mode access
spanning-tree portfast
spanning-tree bpduguard enable
!
interface GigabitEthernet1/0/17
switchport access vlan 111
switchport mode access
spanning-tree portfast
spanning-tree bpduguard enable
!
interface GigabitEthernet1/0/18
switchport access vlan 111
switchport mode access
spanning-tree portfast
spanning-tree bpduguard enable
!
interface GigabitEthernet1/0/19
switchport access vlan 111
switchport mode access
spanning-tree portfast
spanning-tree bpduguard enable
!
interface GigabitEthernet1/0/20
switchport access vlan 111
switchport mode access
spanning-tree portfast
spanning-tree bpduguard enable
!
interface GigabitEthernet1/0/21
!
interface GigabitEthernet1/0/22
!
interface GigabitEthernet1/0/23
!
interface GigabitEthernet1/0/24
!
interface GigabitEthernet1/0/25
no switchport
no ip address
no ip redirects
no ip unreachables
no ip proxy-arp
ip pim sparse-mode
ip igmp version 3
ip ospf message-digest-key 1 md5
udld port aggressive
mls qos trust dscp
channel-group 110 mode on
!
interface GigabitEthernet1/0/26
shutdown
!
interface GigabitEthernet1/0/27
shutdown
!
interface GigabitEthernet1/0/28
shutdown
!
interface GigabitEthernet2/0/1
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 1-19,254
switchport mode trunk
srr-queue bandwidth share 10 10 60 20
queue-set 2
priority-queue out
mls qos trust dscp
channel-group 1 mode active
!
interface GigabitEthernet2/0/2
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 1-19,254
switchport mode trunk
srr-queue bandwidth share 10 10 60 20
queue-set 2
priority-queue out
mls qos trust dscp
channel-group 2 mode active
!
interface GigabitEthernet2/0/3
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 1-19,254
switchport mode trunk
srr-queue bandwidth share 10 10 60 20
queue-set 2
priority-queue out
mls qos trust dscp
channel-group 3 mode active
!
interface GigabitEthernet2/0/4
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 1-19,254
switchport mode trunk
srr-queue bandwidth share 10 10 60 20
queue-set 2
priority-queue out
mls qos trust dscp
channel-group 4 mode active
!
interface GigabitEthernet2/0/5
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 1-19,254
switchport mode trunk
srr-queue bandwidth share 10 10 60 20
queue-set 2
priority-queue out
mls qos trust dscp
channel-group 5 mode active
!
interface GigabitEthernet2/0/6
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 1-19,254
switchport mode trunk
srr-queue bandwidth share 10 10 60 20
queue-set 2
priority-queue out
mls qos trust dscp
channel-group 6 mode active
!
interface GigabitEthernet2/0/7
!
interface GigabitEthernet2/0/8
!
interface GigabitEthernet2/0/9
!
interface GigabitEthernet2/0/10
!
interface GigabitEthernet2/0/11
!
interface GigabitEthernet2/0/12
!
interface GigabitEthernet2/0/13
!
interface GigabitEthernet2/0/14
!
interface GigabitEthernet2/0/15
switchport access vlan 111
switchport mode access
spanning-tree portfast
spanning-tree bpduguard enable
!
interface GigabitEthernet2/0/16
switchport access vlan 111
switchport mode access
spanning-tree portfast
spanning-tree bpduguard enable
!
interface GigabitEthernet2/0/17
switchport access vlan 111
switchport mode access
spanning-tree portfast
spanning-tree bpduguard enable
!
interface GigabitEthernet2/0/18
switchport access vlan 111
switchport mode access
spanning-tree portfast
spanning-tree bpduguard enable
!
interface GigabitEthernet2/0/19
switchport access vlan 111
switchport mode access
spanning-tree portfast
spanning-tree bpduguard enable
!
interface GigabitEthernet2/0/20
switchport access vlan 111
switchport mode access
spanning-tree portfast
spanning-tree bpduguard enable
!
interface GigabitEthernet2/0/21
!
interface GigabitEthernet2/0/22
!
interface GigabitEthernet2/0/23
!
interface GigabitEthernet2/0/24
!
interface GigabitEthernet2/0/25
no switchport
no ip address
no ip redirects
no ip unreachables
no ip proxy-arp
ip pim sparse-mode
ip igmp version 3
ip ospf message-digest-key 1 md5
udld port aggressive
mls qos trust dscp
channel-group 110 mode on
!
interface GigabitEthernet2/0/26
shutdown
!
interface GigabitEthernet2/0/27
shutdown
!
interface GigabitEthernet2/0/28
shutdown
!
interface Vlan1
no ip address
shutdown
!
interface Vlan102
ip dhcp relay information trusted
ip address x.x.x.x 255.255.255.0
ip helper-address x.x.x.x
ip helper-address x.x.x.x
ip helper-address x.x.x.x
ip helper-address x.x.x.x
ip pim sparse-mode
!
interface Vlan103
ip dhcp relay information trusted
ip address x.x.x.x 255.255.255.0
ip helper-address x.x.x.x
ip helper-address x.x.x.x
ip helper-address x.x.x.x
ip helper-address x.x.x.x
ip pim sparse-mode
!
interface Vlan104
ip dhcp relay information trusted
ip address x.x.x.x 255.255.255.0
ip helper-address x.x.x.x
ip helper-address x.x.x.x
ip helper-address x.x.x.x
ip helper-address x.x.x.x
ip pim sparse-mode
!
interface Vlan105
ip dhcp relay information trusted
ip address x.x.x.x 255.255.255.0
ip helper-address x.x.x.x
ip helper-address x.x.x.x
ip helper-address x.x.x.x
ip helper-address x.x.x.x
ip pim sparse-mode
!
interface Vlan106
ip dhcp relay information trusted
ip address x.x.x.x 255.255.255.0
ip helper-address x.x.x.x
ip helper-address x.x.x.x
ip helper-address x.x.x.x
ip helper-address x.x.x.x
ip pim sparse-mode
!
interface Vlan107
ip address x.x.x.x 255.255.255.0
ip helper-address x.x.x.x
ip helper-address x.x.x.x
ip helper-address x.x.x.x
ip helper-address x.x.x.x
ip pim sparse-mode
!
interface Vlan108
ip address x.x.x.x 255.255.255.0
ip helper-address x.x.x.x
ip helper-address x.x.x.x
ip helper-address x.x.x.x
ip helper-address x.x.x.x
ip pim sparse-mode
!
interface Vlan109
ip address x.x.x.x 255.255.255.0
ip helper-address x.x.x.x
ip helper-address x.x.x.x
ip helper-address x.x.x.x
ip helper-address x.x.x.x
ip pim sparse-mode
!
interface Vlan110
ip address x.x.x.x 255.255.255.0
ip helper-address x.x.x.x
ip helper-address x.x.x.x
ip helper-address x.x.x.x
ip helper-address x.x.x.x
ip pim sparse-mode
ip igmp version 3
!
interface Vlan111
ip address x.x.x.x 255.255.255.0
ip helper-address x.x.x.x
ip helper-address x.x.x.x
ip helper-address x.x.x.x
ip helper-address x.x.x.x
ip pim sparse-mode
!
interface Vlan112
ip address x.x.x.x 255.255.255.0
ip helper-address x.x.x.x
ip helper-address x.x.x.x
ip helper-address x.x.x.x
ip helper-address x.x.x.x
ip pim sparse-mode
!
interface Vlan113
ip address x.x.x.x 255.255.255.0
ip helper-address x.x.x.x
ip helper-address x.x.x.x
ip helper-address x.x.x.x
ip helper-address x.x.x.x
ip pim sparse-mode
!
interface Vlan114
ip address x.x.x.x 255.255.255.0
ip helper-address x.x.x.x
ip helper-address x.x.x.x
ip helper-address x.x.x.x
ip helper-address x.x.x.x
ip pim sparse-mode
!
interface Vlan115
no ip address
shutdown
!
interface Vlan116
no ip address
shutdown
!
interface Vlan117
no ip address
shutdown
!
interface Vlan118
no ip address
shutdown
!
interface Vlan254
ip address x.x.x.x 255.255.255.0
!
router ospf 100
log-adjacency-changes
area 0 authentication message-digest
redistribute connected
passive-interface default
no passive-interface GigabitEthernet1/0/25
no passive-interface GigabitEthernet2/0/25
no passive-interface port-channel48
network x.x.x.x 0.0.255.255 area 0
network x.x.x.x 0.0.0.3 area 0
!
ip classless
ip http server
ip http secure-server
ip pim ssm range 2
!
!
access-list 1 permit x.x.x.x
access-list 1 permit x.x.x.x
access-list 1 permit x.x.x.x
access-list 1 permit x.x.x.x
access-list 1 permit x.x.x.x 0.0.0.255
access-list 2 permit x.x.x.x 255.255.0.0
!
snmp-server community
snmp-server community
snmp-server community
snmp-server location
snmp-server contact
snmp-server system-shutdown
snmp-server enable traps vlancreate
snmp-server enable traps vlandelete
snmp-server enable traps flash insertion removal
snmp-server enable traps port-security
snmp-server enable traps envmon fan shutdown supply temperature status
snmp-server enable traps config-copy
snmp-server enable traps config
snmp-server enable traps hsrp
snmp-server enable traps bridge newroot topologychange
snmp-server enable traps stpx inconsistency root-inconsistency loop-inconsistency
snmp-server enable traps syslog
snmp-server enable traps mac-notification change move threshold
snmp-server enable traps vlan-membership
!
control-plane
!
banner login ^C******* ^C
!
line con 0
exec-timeout 0 0
login local
line vty 0 4
access-class 1 in
login local
length 0
transport input ssh
transport output none
line vty 5 15
04-12-2010 07:36 AM
check VLAN/IP Subnet duplication/overlapps.
04-12-2010 07:36 AM
I don't think there isn't too much that can be said until we see the pertinent device configurations, as well as the output of the OSPF neighbors command and perhaps the sh ip ospf command.
Victor
04-12-2010 07:43 AM
The OSPF forms an adjacency fine, with Full neighbour status. Router B is the DR, with router C the BDR, which is what we want.
We are using a basic OSPF config, so just the network statement and md5 encryption. Interestingly, the vlan it has issues with is a /16 common vlan. You can still access it from another vlan, it just knocks out access to that /16 vlan from router B when the OSPF forms the adjaceny.
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