This error:
Mar 2 03:50:32: OSPF: Rcv pkt from 172.26.3.3, Ethernet1/0, area 0.0.0.0 mismatch area 0.0.0.2 in the header
Is coming from the router T1_Backup 172.16.3.6 and here is its config:
T1_Backup#show config
Using 1559 out of 29688 bytes
version 12.3
service timestamps debug datetime
service timestamps log datetime
service password-encryption
!
hostname T1_Backup
!
boot-start-marker
boot-end-marker
!
logging buffered 5000 debugging
enable secret 5 $1$A5dM$89mIexdzvPGU.ZsrjjYsH/
enable password 7 14040B18180127
!
aaa new-model
!
!
aaa session-id common
ip subnet-zero
ip cef
!
!
no ip domain lookup
!
!
interface Loopback0
ip address 1.1.1.8 255.255.255.0
!
interface Ethernet0/0
no ip address
half-duplex
no cdp enable
!
interface Serial0/0
description connected to SDS
ip address 192.168.6.2 255.255.255.0
service-module t1 clock source internal
service-module t1 remote-alarm-enable
!
interface Ethernet1/0
ip address 172.16.3.6 255.255.0.0
half-duplex
!
router ospf 1
log-adjacency-changes
network 172.16.0.0 0.0.255.255 area 0
network 192.168.6.0 0.0.0.255 area 0
!
ip http server
ip classless
ip route 0.0.0.0 0.0.0.0 172.16.3.1
ip route 172.26.0.0 255.255.0.0 Serial0/0
ip route 192.168.6.0 255.255.255.0 Serial0/0
!
!
logging 172.16.1.8
!
!
end
And this error:
*Mar 2 02:25:04: %OSPF-4-ERRRCV: Received invalid packet: mismatch area ID, from backbone area must be virtual-link but not found from 172.16.3.1, FastEthernet0/0,
Is on RP_Cisco1 Router, but also get a similar error from 3 other routers in Area 0.
Using 1263 out of 29688 bytes
!
version 12.3
no parser cache
service timestamps debug datetime
service timestamps log datetime
service password-encryption
!
!
boot-start-marker
boot-end-marker
!
logging buffered 5000 debugging
!
memory-size iomem 25
aaa new-model
!
!
aaa session-id common
ip subnet-zero
!
!
no ip domain lookup
!
ip cef
!
!
interface Loopback0
ip address 1.1.1.7 255.255.255.0
!
interface FastEthernet0/0
description Backup Network
ip address 172.26.3.2 255.255.0.0
speed auto
full-duplex
vrrp 1 ip 172.26.3.1
vrrp 1 timers advertise 3
vrrp 1 authentication text WCHvrrp
!
interface Serial1/0
ip address 192.168.6.1 255.255.255.0
service-module t1 clock source internal
service-module t1 remote-alarm-enable
!
router ospf 1
log-adjacency-changes
network 172.26.0.0 0.0.255.255 area 2
network 192.168.6.0 0.0.0.255 area 0
!
ip classless
ip route 0.0.0.0 0.0.0.0 172.16.1.1
ip route 172.16.0.0 255.255.0.0 Serial1/0
no ip http server
!
end