Multiple logs %OSPF-5-ADJCHG LOADING to FULL, Loading Done

[dan hale]

Hi All, I've been getting errors from my CM RTMT:

FW: [RTMT-ALERT-StandAloneCluster] SDLLinkOutOfService

Based on the above alert this can be due to delay, jitter, packet loss...ect.

We have QOS in place and other than the above alert no complaints from users. Further investigation from the logs of the my remote end I see this:

%OSPF-5-ADJCHG: Process 1, Nbr 10.0.0.1 on GigabitEthernet5/15 from LOADING to FULL, Loading Done

I see this several times every day. Below is a quick topology:

Dell S4810 ---SM Fiber ---- Cisco 6509 ---CM

I see alot of retransmissions when I issue the below command:

Any guidence on what I can adjust or modify...this started just recently.

Remote-Core#sh ip ospf neighbor detail

Neighbor 10.0.0.1, interface address 10.254.253.49

    In the area 0 via interface GigabitEthernet5/15

    Neighbor priority is 1, State is FULL, 276 state changes

    DR is 10.254.253.50 BDR is 10.254.253.49

    Options is 0x42 in Hello (E-bit O-bit)

    Options is 0x42 in DBD (E-bit O-bit)

    Dead timer due in 00:00:32

    Neighbor is up for 03:45:44

    Index 2/2, retransmission queue length 0, number of retransmission 1130

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

    Last retransmission scan length is 1, maximum is 35

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

Neighbor 10.0.0.2, interface address 10.254.253.41

    In the area 0 via interface GigabitEthernet5/16

    Neighbor priority is 1, State is FULL, 6 state changes

    DR is 10.254.253.42 BDR is 10.254.253.41

    Options is 0x42 in Hello (E-bit O-bit)

    Options is 0x42 in DBD (E-bit O-bit)

    Dead timer due in 00:00:39

    Neighbor is up for 3w3d   

    Index 1/1, retransmission queue length 0, number of retransmission 763

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

    Last retransmission scan length is 1, maximum is 2

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

Thanks...

[Bilal Nawaz]

Hello, can you please kindly check that the MTU on both 6509 and the Dell is the same?

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[dan hale]

Hi Bilal,

on the dell side:

MTU 1554 bytes, IP MTU 1500 bytes

On the 6509 side:

MTU 1500 bytes

[Bilal Nawaz]

Hello, Do you see this in your logs too? "too many retransmissions" it's common that if this log is seen that there is an MTU mismatch. Also need to make sure the interfaces are all OK.

Could you kindly do
sh interface gi5/16
sh ip inteface gi5/16

Also is it possible to capture a 'debug ip ospf adj' to get a better insight to what is happening at the time of adjacency drop and recovery.

Is it possible to display some information from the Dell side with regards to OSPF adjacency and interface level info please?

Database packets have the DF bit set in the ip header. For this reason an MTU mismatch could possibly be the cause for this although you have 'ip mtu 1500'

And it's also strange that it started recently.

Sent from Cisco Technical Support iPhone App

[paul driver]

Hello

Please provide some readouts between  the ospf relationship of the 6500 and the dell device.

deb ip ospf adj

sh ip ospf neigbour

If i am readin this correctly, it looks like your system mtu on the Dell is 1500  but the interface mtu is 1554, if so try setting the dell interface to mtu 1500.

res

Paul.

Please don't forget to rate any posts that have been helpful.

Thanks.

[Joseph W. Doherty]

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Posting

I've seen these when neighbor adjacency is lost, i.e. neighbor dead timer fired.  If you enable logging detail in the OSPF process, you'll likely see OSPF working it's way through the other adjacency build steps.

Could you post your interface configs and show interface ospf?