Routing

Hello,

I have 3 Juniper routers and configured OSPF. Router A is directly connected to router B and C. But router B and C are not directly connected. 

It seems to me that I'm seing OSPF route of C on router B but can't ping it. And router A is DR

root@maya> show ospf route 192.168.1.4
Topology default Route Table:

Prefix             Path  Route      NH       Metric NextHop       Nexthop
                   Type  Type       Type            Interface     Address/LSP
192.168.1.4        Intra Router     IP            2 em0.0         192.168.1.1

root@maya> ping 192.168.1.4
PING 192.168.1.4 (192.168.1.4): 56 data bytes
^C
--- 192.168.1.4 ping statistics ---
3 packets transmitted, 0 packets received, 100% packet loss

I can see the ip address in the OSPF database

root@maya> show ospf database

    OSPF database, Area 0.0.0.0
 Type       ID               Adv Rtr           Seq      Age  Opt  Cksum  Len
Router   192.168.1.1      192.168.1.1      0x8000000b   837  0x22 0xaee1  48
Router  *192.168.1.2      192.168.1.2      0x8000000a   836  0x22 0xe098  36
Router   192.168.1.4      192.168.1.4      0x80000009   844  0x22 0xf27f  36
Network  192.168.1.1      192.168.1.1      0x80000003   837  0x22 0xb2d6  32
Network  192.168.1.3      192.168.1.1      0x80000002   844  0x22 0xbcc9  32

Anyone have an idea why I can't ping 192.168.1.4 ?

Thanks

Hi,

Can you provide the output of "show route 192.168.1.2 extensive" from Router C?

Also try to use source address in ping and see if it works, "ping 192.168.1.4 source-address 192.168.1.2" on Router B.

Regards

Surya

Hi Surya,

Here is the output you requested from router C. thanks !

root@maya> show route 192.168.1.2 extensive

inet.0: 3 destinations, 3 routes (3 active, 0 holddown, 0 hidden)
192.168.1.0/24 (1 entry, 0 announced)
        *Direct Preference: 0
                Next hop type: Interface
                Next-hop reference count: 1
                Next hop: via em1.0, selected
                State: <Active Int>
                Age: 46:15
                Task: IF
                AS path: I

=======================

root@maya> ping 192.168.1.4 source 192.168.1.2
PING 192.168.1.4 (192.168.1.4): 56 data bytes
^C
--- 192.168.1.4 ping statistics ---
3 packets transmitted, 0 packets received, 100% packet loss

Hi,

I thought the topology was something like as below. Please correct me if I am wrong.

B-----A-----C

B = 192.168.1.2
A = 192.168.1.1
C = 192.168.1.4

If that was the case, 192.168.1.2 on Router C should have seen as OSPF route instead of Direct Route. Not sure if I am missing something.

root@maya> show route 192.168.1.2 extensive

inet.0: 3 destinations, 3 routes (3 active, 0 holddown, 0 hidden)
192.168.1.0/24 (1 entry, 0 announced)
        *Direct Preference: 0
                Next hop type: Interface
                Next-hop reference count: 1
                Next hop: via em1.0, selected

Regards

Surya

Surya,

You are absolutely correct. The topology is B-A-C.

Why does it show direct connection ? Is there any way of changing it ?

thanks

Hi,

Can you please provide the output of  below commands from all 3 routers?

show route 192.168.1.1 detail

show route 192.168.1.2 detail

show route 192.168.1.4 detail

Also would appreciate if you can provide the configs from all 3 routers.

Regards

Surya

root@maya> show route 192.168.1.1 detail

inet.0: 4 destinations, 5 routes (4 active, 0 holddown, 0 hidden)
192.168.1.1/32 (1 entry, 0 announced)
        *Local  Preference: 0
                Next hop type: Local
                Next-hop reference count: 2
                Interface: em0.0
                State: <Active NoReadvrt Int>
                Age: 44:30
                Task: IF
                AS path: I

root@maya> show route 192.168.1.2 detail

inet.0: 4 destinations, 5 routes (4 active, 0 holddown, 0 hidden)
192.168.1.0/24 (2 entries, 0 announced)
        *Direct Preference: 0
                Next hop type: Interface
                Next-hop reference count: 1
                Next hop: via em0.0, selected
                State: <Active Int>
                Age: 44:32
                Task: IF
                AS path: I
         Direct Preference: 0
                Next hop type: Interface
                Next-hop reference count: 1
                Next hop: via em1.0, selected
                State: <Int>
                Inactive reason: No difference
                Age: 44:31
                Task: IF
                AS path: I

root@maya> show route 192.168.1.4 detail

inet.0: 4 destinations, 5 routes (4 active, 0 holddown, 0 hidden)
192.168.1.0/24 (2 entries, 0 announced)
        *Direct Preference: 0
                Next hop type: Interface
                Next-hop reference count: 1
                Next hop: via em0.0, selected
                State: <Active Int>
                Age: 44:34
                Task: IF
                AS path: I
         Direct Preference: 0
                Next hop type: Interface
                Next-hop reference count: 1
                Next hop: via em1.0, selected
                State: <Int>
                Inactive reason: No difference
                Age: 44:33
                Task: IF
                AS path: I
==================================

root@maya> show route 192.168.1.1 detail

inet.0: 3 destinations, 3 routes (3 active, 0 holddown, 0 hidden)
192.168.1.0/24 (1 entry, 0 announced)
        *Direct Preference: 0
                Next hop type: Interface
                Next-hop reference count: 1
                Next hop: via em1.0, selected
                State: <Active Int>
                Age: 58:27
                Task: IF
                AS path: I

root@maya> show route 192.168.1.2 detail

inet.0: 3 destinations, 3 routes (3 active, 0 holddown, 0 hidden)
192.168.1.0/24 (1 entry, 0 announced)
        *Direct Preference: 0
                Next hop type: Interface
                Next-hop reference count: 1
                Next hop: via em1.0, selected
                State: <Active Int>
                Age: 58:29
                Task: IF
                AS path: I

root@maya> show route 192.168.1.4 detail

inet.0: 3 destinations, 3 routes (3 active, 0 holddown, 0 hidden)
192.168.1.4/32 (1 entry, 0 announced)
        *Local  Preference: 0
                Next hop type: Local
                Next-hop reference count: 1
                Interface: em1.0
                State: <Active NoReadvrt Int>
                Age: 58:30
                Task: IF
                AS path: I
================================

root@maya> show route 192.168.1.1 detail

inet.0: 3 destinations, 3 routes (3 active, 0 holddown, 0 hidden)
192.168.1.0/24 (1 entry, 0 announced)
        *Direct Preference: 0
                Next hop type: Interface
                Next-hop reference count: 1
                Next hop: via em0.0, selected
                State: <Active Int>
                Age: 55:39
                Task: IF
                AS path: I

root@maya>

root@maya> show route 192.168.1.2 detail

inet.0: 3 destinations, 3 routes (3 active, 0 holddown, 0 hidden)
192.168.1.2/32 (1 entry, 0 announced)
        *Local  Preference: 0
                Next hop type: Local
                Next-hop reference count: 1
                Interface: em0.0
                State: <Active NoReadvrt Int>
                Age: 55:40
                Task: IF
                AS path: I

root@maya>

root@maya> show route 192.168.1.4 detail

inet.0: 3 destinations, 3 routes (3 active, 0 holddown, 0 hidden)
192.168.1.0/24 (1 entry, 0 announced)
        *Direct Preference: 0
                Next hop type: Interface
                Next-hop reference count: 1
                Next hop: via em0.0, selected
                State: <Active Int>
                Age: 55:41
                Task: IF
                AS path: I

root@maya>

Hi,

From the logs, it looks like you have configured same subnet on both sides of router A, then it is expected that the ping coming on em0/em1 goes back to same interface.

root@maya> show route 192.168.1.2 detail

inet.0: 4 destinations, 5 routes (4 active, 0 holddown, 0 hidden)
192.168.1.0/24 (2 entries, 0 announced)
        *Direct Preference: 0
                Next hop type: Interface
                Next-hop reference count: 1
                Next hop: via em0.0, selected
                State: <Active Int>
                Age: 44:32
                Task: IF
                AS path: I
         Direct Preference: 0
                Next hop type: Interface
                Next-hop reference count: 1
                Next hop: via em1.0, selected
                State: <Int>
                Inactive reason: No difference
                Age: 44:31
                Task: IF
                AS path: I

root@maya> show route 192.168.1.4 detail

inet.0: 4 destinations, 5 routes (4 active, 0 holddown, 0 hidden)
192.168.1.0/24 (2 entries, 0 announced)
        *Direct Preference: 0
                Next hop type: Interface
                Next-hop reference count: 1
                Next hop: via em0.0, selected
                State: <Active Int>
                Age: 44:34
                Task: IF
                AS path: I
         Direct Preference: 0
                Next hop type: Interface
                Next-hop reference count: 1
                Next hop: via em1.0, selected
                State: <Int>
                Inactive reason: No difference
                Age: 44:33
                Task: IF
                AS path: I

Please have them in different subnets and see if it works.

+---+ .2   192.168.1.0/30   .1 +---+ .1  192.168.2.0/30 .2 +---+

| B |--------------------------| A |-----------------------| C |

+---+                          +---+                       +---+

Regards

Surya

It worked !!

root@routerB> ping 192.168.1.2
PING 192.168.1.2 (192.168.1.2): 56 data bytes
64 bytes from 192.168.1.2: icmp_seq=0 ttl=63 time=6.468 ms
64 bytes from 192.168.1.2: icmp_seq=1 ttl=63 time=1.162 ms
64 bytes from 192.168.1.2: icmp_seq=2 ttl=63 time=1.519 ms
^C
--- 192.168.1.2 ping statistics ---
3 packets transmitted, 3 packets received, 0% packet loss
round-trip min/avg/max/stddev = 1.162/3.050/6.468/2.422 ms

Thank you !!!