RIP OSPF does not activate on secondary IPs

[icyice]

Hello,

I have put together a small testlab for educational purposes containing:

Cisco 877/878/800As.

These are soho routers with the ethernet being non manageable which means all the Fastethernet0-4 ports cannot have IP addresses and you can only set very basic things on them like shutdown, duplex etc.

Instead these routers have 1 outside interface which is the ISDN/ADSL and there is a Vlan1 interface inside which is tapped into the ethernet switch so it can be considered as the internal interface.

What I would've like to reproduce with 4 routers something like this setup:

https://configureterminal.com/wp-content/uploads/2018/08/CCNARouting-examOSPF-EIGRPRIPCCNA-200-125-exam.jpg

However the external interfaces on these routers are not ethernet so I was thinking configuring secondary ips on the links to mimic the following setup.

This was successful, all the routers have 2-3 ips per interface and the configuration format is ok, the neighboors can ping each other on separate virtual subnets.

However I'm not sure if it's because of the Vlan interface or because of the shortcomings of these routers there is absolutely nothing happening once RIP is setup and it's the same when I setup OSPF. I turn on the debug mode for both and I dont see any sent packet any received packet, any changes on the routing table or in their own tables like the 4 routers would be on completely separate networks or the whole routing protocol would not even be turned on.

Any ideas why?

[Joseph W. Doherty · Accepted solution]

Cannot comment on RIP, but I recall (?) OSPF will bring secondaries IP addresses into it, if their secondary IPs match an OSPF network statement. However, I also recall (?), OSPF will only form an OSPF neighbor using primary IPs.

[icyice]

Thanks for the response, you were right it only forms neighbors on the primary IP which sadly ruins my test.

In my test all the routers connected to a management network with a single cable 10.0.0.0/24 which is going into a regular switch.

I have setup various routing subnets in between the routers eg:

R1

10.0.0.1 management

192.168.10.1 route1 ip

192.168.20.1 route2 ip

R2

10.0.0.2 managemnt

192.168.10.2 route1 ip

192.168.30.1 route2 ip

...

Now you can see that although it does take the secondaries into OSPF because the neighbors getting formed on the management network it will always route packets through there so R3 in my setup would be only reachable through R4 from R1 but because they are also all on the same management network if R1 wants to access something connected to R3 it will just connect there directly ignoring R4, R2 on the way. This way I cannot test OSPF very well :(

Thanks for the answer anyway it was the right one!

[Georg Pauwen]

Hello,

can you post the running configs of your routers ?

[icyice]

Hello,

Yes I can post it however if what you say is true this setup will never work as I intended it to work. 

In this setup

R3 is the exit point with a network 172.16.22.0/24

R4 is the entry point what I use with my laptop

and R1 and R2 in between. I could change the first IP of course to be one of the emulated in between route nets but that wouldn't help either since then OSPF would not advertise on the second virtual ip.

Anyway here they are, I just removed the password/secrets/usernames:

R1

version 12.4
service timestamps debug datetime msec
service timestamps log datetime msec
service password-encryption
hostname Cisco1
boot-start-marker
boot-end-marker
no aaa new-model
resource policy
ip cef
ip domain name cisco.lan
interface FastEthernet0
 ip address 192.168.10.1 255.255.255.0 secondary
 ip address 192.168.40.2 255.255.255.0 secondary
 ip address 10.0.0.1 255.255.255.0
 speed auto
interface Serial0
 no ip address
 shutdown
router ospf 1
 router-id 10.0.0.1
 log-adjacency-changes
 network 10.0.0.1 0.0.0.0 area 0
 network 192.168.10.1 0.0.0.0 area 0
 network 192.168.40.2 0.0.0.0 area 0
no ip http server
no ip http secure-server
control-plane
line con 0
 logging synchronous
 login local
line aux 0
line vty 0 4
 login local
 transport input telnet ssh
end



R2

version 12.4
no service pad
service timestamps debug datetime msec
service timestamps log datetime msec
service password-encryption
hostname cisco2
boot-start-marker
boot-end-marker
no aaa new-model
resource policy
ip cef
ip domain name cisco2.cisco.lan
controller DSL 0
 line-term cpe
interface BRI0
 no ip address
 encapsulation hdlc
 shutdown
interface FastEthernet0
interface FastEthernet1
interface FastEthernet2
interface FastEthernet3
interface Vlan1
 ip address 192.168.10.2 255.255.255.0 secondary
 ip address 192.168.20.1 255.255.255.0 secondary
 ip address 10.0.0.2 255.255.255.0
router ospf 1
 router-id 10.0.0.2
 log-adjacency-changes
 network 10.0.0.2 0.0.0.0 area 0
 network 192.168.10.2 0.0.0.0 area 0
 network 192.168.20.1 0.0.0.0 area 0
router ospf 2
 log-adjacency-changes
no ip http server
no ip http secure-server
snmp-server community public RO
control-plane
line con 0
 logging synchronous
 login local
 no modem enable
line aux 0
line vty 0 4
 login local
 transport input ssh
scheduler max-task-time 5000

end

R3

version 12.4
no service pad
service timestamps debug datetime msec
service timestamps log datetime msec
service password-encryption
service sequence-numbers
hostname Cisco3
boot-start-marker
boot-end-marker
memory-size iomem 5
aaa new-model
aaa authentication login vpn local
aaa authorization network hw-client-groupname local 
aaa authorization network vpn local 
aaa session-id common
resource policy
clock timezone MET 1
ip cef
no ip domain lookup
ip domain name cisco3.cisco.lan
ip ssh authentication-retries 4
interface Ethernet0
 description connected to HQ LAN
 ip address 192.168.20.2 255.255.255.0 secondary
 ip address 192.168.30.1 255.255.255.0 secondary
 ip address 10.0.0.3 255.255.255.0
 no cdp enable
interface Ethernet1
 description connected to INTERNET
 ip address 172.16.22.1 255.255.255.0
 ip tcp adjust-mss 1460
 duplex auto
 no cdp enable
interface Ethernet2
 no ip address
 shutdown
interface FastEthernet1
 duplex auto
 speed auto
interface FastEthernet2
 duplex auto
 speed auto
interface FastEthernet3
 duplex auto
 speed auto
interface FastEthernet4
 duplex auto
 speed auto
router ospf 1
 router-id 10.0.0.3
 log-adjacency-changes
 network 10.0.0.3 0.0.0.0 area 0
 network 172.16.22.1 0.0.0.0 area 0
 network 192.168.20.2 0.0.0.0 area 0
 network 192.168.30.1 0.0.0.0 area 0
no ip http server
no ip http secure-server
logging origin-id ip
logging source-interface Ethernet0
no cdp run
control-plane
alias exec s show ip int brief
privilege exec level 4 show
line con 0
 no modem enable
line aux 0
line vty 0 4
 exec-timeout 120 0
 length 0
 transport input ssh
scheduler max-task-time 5000
end



R4
version 12.4
no service pad
service timestamps debug datetime msec
service timestamps log datetime msec
service password-encryption
hostname Cisco4
boot-start-marker
boot-end-marker
logging buffered 51200 warnings
no aaa new-model
resource policy
no ip subnet-zero
ip cef
no ip domain lookup
ip domain name cisco1.cisco.lan
ip ssh source-interface Vlan1
interface ATM0
 no ip address
 shutdown
 no atm ilmi-keepalive
 dsl operating-mode auto 
interface FastEthernet0
interface FastEthernet1
interface FastEthernet2
interface FastEthernet3
interface Vlan1
 description $ETH-SW-LAUNCH$$INTF-INFO-HWIC 4ESW$
 ip address 192.168.30.2 255.255.255.0 secondary
 ip address 192.168.40.1 255.255.255.0 secondary
 ip address 10.0.0.4 255.255.255.0
router ospf 1
 router-id 10.0.0.4
 log-adjacency-changes
 network 10.0.0.4 0.0.0.0 area 0
 network 192.168.30.2 0.0.0.0 area 0
 network 192.168.40.1 0.0.0.0 area 0
no ip classless
no ip http server
no ip http secure-server
no cdp run
control-plane
line con 0
 logging synchronous
 login local
 no modem enable
line aux 0
line vty 0 4
 login local
 transport input ssh
scheduler max-task-time 5000
ntp clock-period 17175067
end