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OSPF issue (EXSTART/DR)

enriquebs
Level 1
Level 1

HI all,

I have a fiber link between two 7606 routers, the thing is the OSPF isn´t able to change to the FULL state, it stops in the EXSTART. Here is the two interfaces configuration:

interface GE-WAN1/1

mtu 1508

ip address 10.9.129.1 255.255.255.252

ip mtu 1500

ip pim sparse-mode

ip ospf cost 1

no negotiation auto

tag-switching ip

mls qos trust dscp

end

interface GE-WAN2/1

mtu 1508

ip address 10.9.129.2 255.255.255.252

ip mtu 1500

ip pim sparse-mode

no negotiation auto

tag-switching ip

mls qos trust dscp

end

And here an event which is shown all the time if you activate the term mon:

Mar 27 11:55:07: %OSPF-5-ADJCHG: Process 100, Nbr 10.9.128.66 on GE-WAN1/1 from EXSTART to DOWN, Neighbor Down: Too many retransmissions

I thought about any problem in the MTUs config, but they looks fine...

Any idea?

Thanks in advance

21 Replies 21

spremkumar
Level 9
Level 9

hi

can you try configuring mtu 1500 instead of mtu 1508 which is there at present..

regds

I can't, because when I type the "mpls mtu 1508" command it changes the "mtu 1500" to "mtu 1508". By the way, I have another link in the same router working fine with MTU 1508. And I need 1508 in the interface MTU because of the VPN environment.

Hi,

I don't believe the MTU is the issue here.. if that were the case, one side would be in ExStart and the other would be in Exchange...

Could you post your 'router ospf' configs on each side and the output of 'sh ip ospf interface' for the two interfaces ?

Paresh

Hi,

Here are the outputs, just from one router, the other router is not reachable for the moment (due ospf).

R1#sh ip osp

Routing Process "ospf 100" with ID 10.9.128.65

Supports only single TOS(TOS0) routes

Supports opaque LSA

Supports Link-local Signaling (LLS)

Initial SPF schedule delay 5000 msecs

Minimum hold time between two consecutive SPFs 10000 msecs

Maximum wait time between two consecutive SPFs 10000 msecs

Incremental-SPF disabled

Minimum LSA interval 5 secs

Minimum LSA arrival 1000 msecs

LSA group pacing timer 240 secs

Interface flood pacing timer 33 msecs

Retransmission pacing timer 66 msecs

Number of external LSA 0. Checksum Sum 0x000000

Number of opaque AS LSA 0. Checksum Sum 0x000000

Number of DCbitless external and opaque AS LSA 0

Number of DoNotAge external and opaque AS LSA 0

Number of areas in this router is 1. 1 normal 0 stub 0 nssa

External flood list length 0

Non-Stop Forwarding enabled

Area BACKBONE(0)

Number of interfaces in this area is 8 (2 loopback)

Area has no authentication

SPF algorithm last executed 00:06:03.136 ago

SPF algorithm executed 4 times

Area ranges are

Number of LSA 19. Checksum Sum 0x1406F9

Number of opaque link LSA 0. Checksum Sum 0x000000

Number of DCbitless LSA 0

Number of indication LSA 0

Number of DoNotAge LSA 0

Flood list length 0

R1#sh ip ospf interface ge1/1

GE-WAN1/1 is up, line protocol is up

Internet Address 10.9.129.1/30, Area 0

Process ID 100, Router ID 10.9.128.65, Network Type BROADCAST, Cost: 1

Transmit Delay is 1 sec, State BDR, Priority 1

Designated Router (ID) 10.9.128.66, Interface address 10.9.129.2

Backup Designated router (ID) 10.9.128.65, Interface address 10.9.129.1

Flush timer for old DR LSA due in 00:02:59

Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5

oob-resync timeout 40

Hello due in 00:00:07

Index 5/5, flood queue length 0

Next 0x0(0)/0x0(0)

Last flood scan length is 0, maximum is 8

Last flood scan time is 0 msec, maximum is 4 msec

Neighbor Count is 1, Adjacent neighbor count is 0

Suppress hello for 0 neighbor(s)

hi

I did notice tag-switching is enabled out there unde those interfaces but offlate what i have learned was enabling the physical interface mtu will do(esp with 7200 & 7600) ,not reqd to key in seperate keyword for mpls mtu.

Pls do reset the interface back to default config and reconfigure them back without keying in ip mtu 1500,let alone mtu 1508 be there under the config.

regds

Is there any chance at all that you could enable 'debug ip ospf adj' on your router at all ? That might give more of a clue as to what is wrong...

Paresh

HI,

Here is the output, but I did a deb ip osp eve because there isn't adj information when I type the debug.

R1#debug ip ospf ad

R1#debug ip ospf adj

OSPF adjacency events debugging is on

R1#term mon

R1#debug ip ospf eve

OSPF events debugging is on

R1#

Mar 27 12:42:39: OSPF: Rcv hello from 10.9.128.66 area 0 from GE-WAN1/1 10.9.129.2

Mar 27 12:42:39: OSPF:

OSPF: Nbr 10.9.128.66 10.9.129.2 GE-WAN1/1 is currently ignored

R1#

Mar 27 12:42:47: OSPF: Send hello to 224.0.0.5 area 0 on GE-WAN1/1 from 10.9.129.1

R1#

Mar 27 12:42:49: OSPF: Rcv hello from 10.9.128.66 area 0 from GE-WAN1/1 10.9.129.2

Mar 27 12:42:49: OSPF:

OSPF: Nbr 10.9.128.66 10.9.129.2 GE-WAN1/1 is currently ignored

R1#

Mar 27 12:42:57: OSPF: 0.0.0.0 address 10.9.129.2 on GE-WAN1/1 is dead

Mar 27 12:42:57: OSPF: 0.0.0.0 address 10.9.129.2 on GE-WAN1/1 is dead, state DOWN

Mar 27 12:42:57: %OSPF-5-ADJCHG: Process 100, Nbr 0.0.0.0 on GE-WAN1/1 from DOWN to DOWN, Neighbor Down: Ignore timer expired

R1#

Mar 27 12:42:57: OSPF: Neighbor change Event on interface GE-WAN1/1

Mar 27 12:42:57: OSPF: DR/BDR election on GE-WAN1/1

Mar 27 12:42:57: OSPF: Elect BDR 0.0.0.0

Mar 27 12:42:57: OSPF: Elect DR 10.9.128.65

Mar 27 12:42:57: DR: 10.9.128.65 (Id) BDR: none

Mar 27 12:42:57: OSPF: Send hello to 224.0.0.5 area 0 on GE-WAN1/1 from 10.9.129.1

R1#

Mar 27 12:42:59: OSPF: Rcv hello from 10.9.128.66 area 0 from GE-WAN1/1 10.9.129.2

Mar 27 12:42:59: OSPF: 2 Way Communication to 10.9.128.66 on GE-WAN1/1, state 2WAY

Mar 27 12:42:59: OSPF: Neighbor change Event on interface GE-WAN1/1

Mar 27 12:42:59: OSPF: DR/BDR election on GE-WAN1/1

Mar 27 12:42:59: OSPF: Elect BDR 0.0.0.0

Mar 27 12:42:59: OSPF: Elect DR 10.9.128.66

Mar 27 12:42:59: OSPF: Elect BDR 10.9.128.65

Mar 27 12:42:59: OSPF: Elect DR 10.9.128.66

Mar 27 12:42:59: DR: 10.9.128.66 (Id) BDR: 10.9.128.65 (Id)

Mar 27 12:42:59: OSPF: Send DBD to 10.9.128.66 on GE-WAN1/1 seq 0x1F8 opt 0x52 flag 0x7 len 32

Mar 27 12:42:59: OSPF: Set GE-WAN1/1 flush timer

Mar 27 12:42:59: OSPF: Remember old DR 10.9.128.65 (id)

R1#

Mar 27 12:42:59: OSPF: Neighbor change Event on interface GE-WAN1/1

Mar 27 12:42:59: OSPF: DR/BDR election on GE-WAN1/1

Mar 27 12:42:59: OSPF: Elect BDR 10.9.128.65

Mar 27 12:42:59: OSPF: Elect DR 10.9.128.66

Mar 27 12:42:59: DR: 10.9.128.66 (Id) BDR: 10.9.128.65 (Id)

Mar 27 12:42:59: OSPF: End of hello processing

Mar 27 12:42:59: OSPF: Reset old DR on GE-WAN1/1

R1#u all

All possible debugging has been turned off

R1#

Mar 27 12:43:04: OSPF: Send DBD to 10.9.128.66 on GE-WAN1/1 seq 0x1F8 opt 0x52 flag 0x7 len 32

Mar 27 12:43:04: OSPF: Retransmitting DBD to 10.9.128.66 on GE-WAN1/1 [1]

HI,

It´s done, but there isn´t change... it continues in EXSTART/DR.

Did you mean that you had enabled the debug ? If so, could you post the output you get ?

Paresh.

Did you mean that you had enabled the debug ? If so, could you post the output you get ?

Paresh.

Here are the deb ip osp ev and packets output:

Mar 27 13:00:49: OSPF: Send DBD to 10.9.128.66 on GE-WAN1/1 seq 0x2444 opt 0x52 flag 0x7 len 32

Mar 27 13:00:49: OSPF: Retransmitting DBD to 10.9.128.66 on GE-WAN1/1 [20]

Mar 27 13:00:49: OSPF: Rcv hello from 10.9.128.66 area 0 from GE-WAN1/1 10.9.129.2

Mar 27 13:00:49: OSPF: End of hello processing

Mar 27 13:00:50: OSPF: rcv. v:2 t:1 l:48 rid:10.9.128.75

aid:0.0.0.0 chk:C0D1 aut:0 auk: from GE-WAN1/2

Mar 27 13:00:52: OSPF: rcv. v:2 t:1 l:48 rid:10.9.128.67

aid:0.0.0.0 chk:C0E1 aut:0 auk: from GE-WAN2/1

Mar 27 13:00:53: OSPF: rcv. v:2 t:1 l:52 rid:10.9.128.76

aid:0.0.0.0 chk:37A1 aut:0 auk: from GigabitEthernet1/1.3001

Mar 27 13:00:54: OSPF: Send DBD to 10.9.128.66 on GE-WAN1/1 seq 0x2444 opt 0x52 flag 0x7 len 32

Mar 27 13:00:54: OSPF: Retransmitting DBD to 10.9.128.66 on GE-WAN1/1 [21]

Mar 27 13:00:55: OSPF: rcv. v:2 t:1 l:52 rid:10.9.128.68

aid:0.0.0.0 chk:3780 aut:0 auk: from GigabitEthernet2/1.3002

Mar 27 13:00:55: OSPF: rcv. v:2 t:1 l:52 rid:10.9.128.68

aid:0.0.0.0 chk:37A1 aut:0 auk: from GigabitEthernet1/1.3001

Mar 27 13:00:56: OSPF: rcv. v:2 t:1 l:48 rid:10.9.128.74

aid:0.0.0.0 chk:C0CA aut:0 auk: from GE-WAN2/2

Mar 27 13:00:57: OSPF: Send hello to 224.0.0.5 area 0 on GE-WAN1/1 from 10.9.129.1

Mar 27 13:00:57: OSPF: rcv. v:2 t:1 l:52 rid:10.9.128.77

aid:0.0.0.0 chk:3780 aut:0 auk: from GigabitEthernet2/1.3002

Mar 27 13:00:59: OSPF: Send DBD to 10.9.128.66 on GE-WAN1/1 seq 0x2444 opt 0x52 flag 0x7 len 32

Mar 27 13:00:59: OSPF: Retransmitting DBD to 10.9.128.66 on GE-WAN1/1 [22]

Mar 27 13:00:59: OSPF: rcv. v:2 t:1 l:48 rid:10.9.128.66

aid:0.0.0.0 chk:C0F2 aut:0 auk: from GE-WAN1/1

Mar 27 13:00:59: OSPF: Rcv hello from 10.9.128.66 area 0 from GE-WAN1/1 10.9.129.2

Mar 27 13:00:59: OSPF: End of hello processing

Mar 27 13:01:00: OSPF: rcv. v:2 t:1 l:48 rid:10.9.128.75

aid:0.0.0.0 chk:C0D1 aut:0 auk: from GE-WAN1/2

Mar 27 13:01:02: OSPF: rcv. v:2 t:1 l:48 rid:10.9.128.67

aid:0.0.0.0 chk:C0E1 aut:0 auk: from GE-WAN2/1

Mar 27 13:01:03: OSPF: rcv. v:2 t:1 l:52 rid:10.9.128.76

aid:0.0.0.0 chk:37A1 aut:0 auk: from GigabitEthernet1/1.3001

Mar 27 13:01:04: OSPF: Send DBD to 10.9.128.66 on GE-WAN1/1 seq 0x2444 opt 0x52 flag 0x7 len 32

Mar 27 13:01:04: OSPF: Retransmitting DBD to 10.9.128.66 on GE-WAN1/1 [23]

Mar 27 13:01:05: OSPF: rcv. v:2 t:1 l:52 rid:10.9.128.68

aid:0.0.0.0 chk:3780 aut:0 auk: from GigabitEthernet2/1.3002

Mar 27 13:01:05: OSPF: rcv. v:2 t:1 l:52 rid:10.9.128.68

aid:0.0.0.0 chk:37A1 aut:0 auk: from GigabitEthernet1/1.3001

Mar 27 13:01:06: OSPF: rcv. v:2 t:1 l:48 rid:10.9.128.74

aid:0.0.0.0 chk:C0CA aut:0 auk: from GE-WAN2/2

Mar 27 13:01:07: OSPF: Send hello to 224.0.0.5 area 0 on GE-WAN1/1 from 10.9.129.1

Mar 27 13:01:07: OSPF: rcv. v:2 t:1 l:52 rid:10.9.128.77

aid:0.0.0.0 chk:3780 aut:0 auk: from GigabitEthernet2/1.3002

u all

All possible debugging has been turned off

Mar 27 13:01:09: OSPF: Send DBD to 10.9.128.66 on GE-WAN1/1 seq 0x2444 opt 0x52 flag 0x7 len 32

Mar 27 13:01:09: OSPF: Retransmitting DBD to 10.9.128.66 on GE-WAN1/1 [24]

Mar 27 13:01:09: OSPF: rcv. v:2 t:1 l:48 rid:10.9.128.66

aid:0.0.0.0 chk:C0F2 aut:0 auk: from GE-WAN1/1

Mar 27 13:01:09: OSPF: Rcv hello from 10.9.128.66 area 0 from GE-WAN1/1 10.9.129.2

Mar 27 13:01:09: OSPF: End of hello processing

Actually, it does point to an MTU issue. The DBDs from this router are not getting to the other and that's why it keeps re-transmitting and eventually gives up.

Are these routers directly connected or do you have a switch in the middle ?

Paresh

There are three or four three JDS (Transmision Devices) in the middle, It is a point to point fiber link between two 7606 routers.

Ok thanks...

I was wondering why you can't get into that other router to get show/debug output. Surely you can just telnet to 10.9.129.2 ? If so, could you get the debugs from that router ? And also the 'sh ip ospf inter' ?

Paresh

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