Routing

Hi,

I have two MX 104 box connected via switches. I am trying establish OSPF between them. 

Unfortunately, router-A  OSPF stuck at init state while router-B not showing ospf neighbor. While troubleshooting it seems router-A can't ping router-B. 

router-A# run ping 172.29.2.6    
PING 172.29.2.6 (172.29.2.6): 56 data bytes
^C
--- 172.29.2.6 ping statistics ---
6 packets transmitted, 0 packets received, 100% packet loss

but If I ping with source addess it works

router-A# run ping 172.29.2.6 source 172.29.2.5                 
PING 172.29.2.6 (172.29.2.6): 56 data bytes
64 bytes from 172.29.2.6: icmp_seq=0 ttl=64 time=1.125 ms
64 bytes from 172.29.2.6: icmp_seq=1 ttl=64 time=1.092 ms
^C
--- 172.29.2.6 ping statistics ---
2 packets transmitted, 2 packets received, 0% packet loss
round-trip min/avg/max/stddev = 1.092/1.109/1.125/0.017 ms

Again, If I ping from router-B it works without source 

router-B# run ping 172.29.2.5    
PING 172.29.2.5 (172.29.2.5): 56 data bytes
64 bytes from 172.29.2.5: icmp_seq=0 ttl=62 time=3.213 ms
64 bytes from 172.29.2.5: icmp_seq=1 ttl=62 time=1.409 ms
64 bytes from 172.29.2.5: icmp_seq=2 ttl=62 time=2.064 ms

--- 172.29.2.5 ping statistics ---
3 packets transmitted, 3 packets received, 0% packet loss
round-trip min/avg/max/stddev = 1.409/2.229/3.213/0.746 ms

Can anyone guide me what might be wrong here ?

TIA

Generally with ospf in the init state some parameter is mismatched between the neighbors.

What are your ospf configurations?

Confirm the subnet mask matches on both interfaces.

Another common problem is mtu mismatch being detected so the neighbor will not come up.

So confirm all the physical links have matching mtu.

both side OSPF configuration is same

router-A# show protocols ospf   
reference-bandwidth 100g;
area 0.0.0.0 {
    interface irb.113;
       interface-type p2p;
    }
    interface lo0.0 {
        passive;
    }
}

Again I tried to find subnet and mtu mismatch. But both are same

router-A# run show interfaces irb.113 detail                                
  Logical interface irb.113 (Index 335) (SNMP ifIndex 571) (Generation 156)
    Description: 
    Flags: Up SNMP-Traps 0x0 Encapsulation: ENET2
    Bandwidth: 1000mbps
    Routing Instance: default-switch Bridging Domain: 113
    Traffic statistics:
     Input  bytes  :              2159316
     Output bytes  :              2808542
     Input  packets:                28410
     Output packets:                28853
    Local statistics:
     Input  bytes  :              2159240
     Output bytes  :              2808542
     Input  packets:                28409
     Output packets:                28853
    Transit statistics:
     Input  bytes  :                   76                    0 bps
     Output bytes  :                    0                    0 bps
     Input  packets:                    1                    0 pps
     Output packets:                    0                    0 pps
    Protocol inet, MTU: 1500
    Max nh cache: 75000, New hold nh limit: 75000, Curr nh cnt: 1, Curr new hold cnt: 0,
    NH drop cnt: 0
    Generation: 178, Route table: 0
      Flags: Sendbcast-pkt-to-re
      Addresses, Flags: Is-Preferred Is-Primary
        Destination: 172.29.2.4/30, Local: 172.29.2.5, Broadcast: 172.29.2.7,
        Generation: 166
    Protocol multiservice, MTU: 1500, Generation: 179, Route table: 0
      Policer: Input: __default_arp_policer__

router-B# run show interfaces irb.113 detail 
  Logical interface irb.113 (Index 397) (SNMP ifIndex 750)
   (Generation 1039)
    Description: 
    Flags: Up SNMP-Traps 0x0 Encapsulation: ENET2
    Bandwidth: 1000mbps
    Routing Instance: default-switch Bridging Domain: 113
    Traffic statistics:
     Input  bytes  :               858352
     Output bytes  :             10711342
     Input  packets:                10762
     Output packets:               122012
    Local statistics:
     Input  bytes  :               857592
     Output bytes  :              5912256
     Input  packets:                10750
     Output packets:                72750
    Transit statistics:
     Input  bytes  :                  760                    0 bps
     Output bytes  :              4799086                    0 bps
     Input  packets:                   12                    0 pps
     Output packets:                49262                    0 pps
    Protocol inet, MTU: 1500
    Max nh cache: 75000, New hold nh limit: 75000, Curr nh cnt: 1,
    Curr new hold cnt: 0, NH drop cnt: 0
    Generation: 1287, Route table: 0
      Flags: Sendbcast-pkt-to-re
      Addresses, Flags: Is-Preferred Is-Primary
        Destination: 172.29.2.4/30, Local: 172.29.2.6,
        Broadcast: 172.29.2.7, Generation: 899
    Protocol multiservice, MTU: 1500, Generation: 1288,
    Route table: 0
      Policer: Input: __default_arp_policer__

Are there routing instances configured on the devices and if so what is the membership of the irb interface in relation to these?

Since the ping without source does not work perhaps there are some duplicate routing paths.  What is the route table for just the neighbor ip address on each device.

Also confirm the bridge domain configuration and interface memberships are all as expected.

Hello,

---

@jasim21 wrote:

 

Unfortunately, router-A  OSPF stuck at init state while router-B not showing ospf neighbor. While troubleshooting it seems router-A can't ping router-B. 

 Check interface netmask on both routers.

I am wiiling to bet that router-A has /32 netmask on LAN interface which explains Your grief.

HTH

Thx
Alex

Thanks for your answer. But I have double cheecked both are in 172.29.2.4/30 subnet.

Are you seeing the ospf hellos received on either side ? hellos will be multicast on p2p network type. subnet mask mismatch should not effect on p2p links as per rfc 2328.

Do you have any kind of the filters configured on the devices? 

Best

Mu

Hi,

First of all, let's forget about the ping without a "source", usually it should be using lo0 address of source. Since OSPF doesn't come up, in most cases, you won't have other end's lo0 address in your routing table 

Then, the situation is, you have direct ping working, configuration of OSPF is also matching. Let's do this:

1. >monitor traffic interface irb.xxx no-resolve <<<<<<<Let's check if you are seeing OSPF hellos

2. Check if there's any filter on lo0 interface, layer 2 interface and irb interface and forwarding-options/forwarding-tables  

3. You can also write a filter on irb.xxx to check if you are receiving any OSPF packets 

   set interfaces irb unit xxx family inet filter input test
   set firewall family inet filter test term 1 from protocol ospf
   set firewall family inet filter test term 1 then count ospf-packet
   set firewall family inet filter test term 1 then accept
   set firewall family inet filter test term 2 then accept

Focus on configuration part. Mostly it can be fixed by config change