OSPF - Neighbour Relationship

rsrikant · ‎04-15-2013

Hi

I have 2 Cisco Catalyst 6509 switches connected directly using direct point to point link.

The OSPF is configured for point - point link.

The currently the interface is down administratively.

I will unshut the port . After that i would like to know how much time will it take for the ospf to establish the neighbour relation.

The default timers for the OSPF are

hello 10, dead 40, wait 40 & retransmit 5.

In the above scenario how much time will it take for the ospf interfaces to form the neighbour relation.

Bilal Nawaz · ‎04-15-2013

Hello, i've experienced extremely quick neighborship builds as demonstrated in the debug ip packet below.

I have R1 - 1.1.1.1 and R2 1.1.1.2 connected via fastethernet interfaces.

R1#

*Mar 1 00:04:36.875: IP: s=1.1.1.2 (FastEthernet0/0), d=224.0.0.5, len 76, rcvd 0 [FIRST PACKET FROM R2]

*Mar 1 00:04:36.879: IP: s=1.1.1.1 (local), d=224.0.0.5 (FastEthernet0/0), len 80, sending broad/multicast

*Mar 1 00:04:36.895: IP: s=1.1.1.2 (FastEthernet0/0), d=224.0.0.5, len 64, rcvd 0

*Mar 1 00:04:36.899: IP: s=1.1.1.1 (local), d=224.0.0.5 (FastEthernet0/0), len 64, sending broad/multicast

*Mar 1 00:04:36.899: IP: s=1.1.1.1 (local), d=224.0.0.5 (FastEthernet0/0), len 84, sending broad/multicast

*Mar 1 00:04:36.923: IP: s=1.1.1.2 (FastEthernet0/0), d=224.0.0.5, len 80, rcvd 0

*Mar 1 00:04:36.939: IP: s=1.1.1.2 (FastEthernet0/0), d=224.0.0.5, len 64, rcvd 0

*Mar 1 00:04:36.943: %OSPF-5-ADJCHG: Process 1, Nbr 1.1.1.2 on FastEthernet0/0 from LOADING to FULL, Loading Done

So time from

*Mar 1 00:04:36.875: till *Mar 1 00:04:36.943:

Took 71ms to converge, Lets have a look from R2's point of view:

R2(config-if)#no shut

R2(config-if)#ip ospf 1 area 0

*Mar 1 00:04:33.675: IP: s=1.1.1.2 (local), d=224.0.0.5 (FastEthernet0/0), len 76, sending broad/multicast [ FIRST PACKET SENT BY R2 ]

*Mar 1 00:04:33.739: IP: s=1.1.1.1 (FastEthernet0/0), d=224.0.0.5, len 80, rcvd 0

*Mar 1 00:04:33.743: IP: s=1.1.1.2 (local), d=224.0.0.5 (FastEthernet0/0), len 64, sending broad/multicast

*Mar 1 00:04:33.743: IP: s=1.1.1.2 (local), d=224.0.0.5 (FastEthernet0/0), len 80, sending broad/multicast

*Mar 1 00:04:33.771: IP: s=1.1.1.1 (FastEthernet0/0), d=224.0.0.5, len 64, rcvd 0

*Mar 1 00:04:33.787: IP: s=1.1.1.1 (FastEthernet0/0), d=224.0.0.5, len 84, rcvd 0

*Mar 1 00:04:33.791: IP: s=1.1.1.2 (local), d=224.0.0.5 (FastEthernet0/0), len 64, sending broad/multicast

*Mar 1 00:04:33.807: IP: s=1.1.1.1 (FastEthernet0/0), d=224.0.0.5, len 64, rcvd 0

*Mar 1 00:04:33.811: IP: s=1.1.1.2 (local), d=224.0.0.5 (FastEthernet0/0), len 56, sending broad/multicast

*Mar 1 00:04:33.827: IP: s=1.1.1.1 (FastEthernet0/0), d=224.0.0.5, len 84, rcvd 0

*Mar 1 00:04:33.831: %OSPF-5-ADJCHG: Process 1, Nbr 1.1.1.1 on FastEthernet0/0 from LOADING to FULL, Loading Done

R2 shows between *Mar 1 00:04:33.675: - *Mar 1 00:04:33.831:

which is 156ms

So were talking milli-seconds

Hope this helps

Please rate useful posts and remember to mark any solved questions as answered. Thank you.

Please rate useful posts & remember to mark any solved questions as answered. Thank you.

rsrikant · ‎04-15-2013

What is the configuration of the OSPF on these 2 interfaces.

What are the OSPF timers ? Is this link configured for point - point link.

Bilal Nawaz · ‎04-15-2013

Hello, So just to answer your questions, im using default timers and yes, they are point to point ....:

Running config of R1:

R1#show run int fa0/0

Building configuration...

Current configuration : 144 bytes

!

interface FastEthernet0/0

ip address 1.1.1.1 255.255.255.252

ip ospf network point-to-point

ip ospf 1 area 0

duplex auto

speed auto

end

R1#show ip ospf 1 interface fa0/0

FastEthernet0/0 is up, line protocol is up

Internet Address 1.1.1.1/30, Area 0

Process ID 1, Router ID 1.1.1.1, Network Type POINT_TO_POINT, Cost: 10

Enabled by interface config, including secondary ip addresses

Transmit Delay is 1 sec, State POINT_TO_POINT

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

oob-resync timeout 40

Hello due in 00:00:07

Supports Link-local Signaling (LLS)

Index 1/1, flood queue length 0

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

Last flood scan length is 1, maximum is 1

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

Neighbor Count is 1, Adjacent neighbor count is 1

Adjacent with neighbor 1.1.1.2

Suppress hello for 0 neighbor(s)

R2#show run int fa0/0

Building configuration...

Current configuration : 144 bytes

!

interface FastEthernet0/0

ip address 1.1.1.2 255.255.255.252

ip ospf network point-to-point

ip ospf 1 area 0

duplex auto

speed auto

end

R2#show ip ospf 1 interface fa0/0

FastEthernet0/0 is up, line protocol is up

Internet Address 1.1.1.2/30, Area 0

Process ID 1, Router ID 1.1.1.2, Network Type POINT_TO_POINT, Cost: 10

Enabled by interface config, including secondary ip addresses

Transmit Delay is 1 sec, State POINT_TO_POINT

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

oob-resync timeout 40

Hello due in 00:00:03

Supports Link-local Signaling (LLS)

Index 1/1, flood queue length 0

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

Last flood scan length is 1, maximum is 1

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

Neighbor Count is 1, Adjacent neighbor count is 1

Adjacent with neighbor 1.1.1.1

Suppress hello for 0 neighbor(s)

Hope this helps

Please rate useful posts and remember to mark any solved questions as answered. Thank you.

Please rate useful posts & remember to mark any solved questions as answered. Thank you.

rsrikant · ‎04-15-2013

thanks

I understand that it takes around 156 ms to for the neighbour relation

Let me know how much time it too to learn the routing details in these links & also how much time it takes to forward the packets or traffic on this link.

Let me know how much it will take for the above.

Bilal Nawaz · ‎04-15-2013

The time differs with this as it all depends on how many prefixes are in the OSPF database. On R2 I have created a loopback and am redistributing connected... We will see how quick I learn about this route. I did a no shut on R2's interface:

*Mar 1 02:19:36.803: to *Mar 1 02:19:36.915: Was the neighborship time it took - 112ms

*Mar 1 02:19:36.803: to *Mar 1 02:19:41.939: Was the neighborship and the learning of 1 route to 100.0.0.1 which is around 4 seconds. All using default timers.

R1#

*Mar 1 02:19:36.803: OSPF: rcv. v:2 t:1 l:44 rid:1.1.1.2 ###FIRST PACKET FROM R2###

aid:0.0.0.0 chk:E99F aut:0 auk: from FastEthernet0/0

*Mar 1 02:19:36.803: OSPF: Rcv hello from 1.1.1.2 area 0 from FastEthernet0/0 1.1.1.2

*Mar 1 02:19:36.803: OSPF: Send immediate hello to nbr 1.1.1.2, src address 1.1.1.2, on FastEthernet0/0

*Mar 1 02:19:36.807: OSPF: Send hello to 224.0.0.5 area 0 on FastEthernet0/0 from 1.1.1.1

*Mar 1 02:19:36.807: OSPF: End of hello processing

*Mar 1 02:19:36.823: OSPF: rcv. v:2 t:2 l:32 rid:1.1.1.2

aid:0.0.0.0 chk:82CB aut:0 auk: from FastEthernet0/0

*Mar 1 02:19:36.823: OSPF: Rcv DBD from 1.1.1.2 on FastEthernet0/0 seq 0x212C opt 0x52 flag 0x7 len 32 mtu 1500 state INIT

*Mar 1 02:19:36.827: OSPF: 2 Way Communication to 1.1.1.2 on FastEthernet0/0, state 2WAY

*Mar 1 02:19:36.827: OSPF: Send DBD to 1.1.1.2 on FastEthernet0/0 seq 0x93D opt 0x52 flag 0x7 len 32

*Mar 1 02:19:36.827: OSPF: NBR Negotiation Done. We are the SLAVE

*Mar 1 02:19:36.831: OSPF: Send DBD to 1.1.1.2 on FastEthernet0/0 seq 0x212C opt 0x52 flag 0x2 len 92

*Mar 1 02:19:36.835: OSPF: rcv. v:2 t:1 l:48 rid:1.1.1.2

aid:0.0.0.0 chk:E799 aut:0 auk: from FastEthernet0/0

*Mar 1 02:19:36.835: OSPF: Rcv hello from 1.1.1.2 area 0 from FastEthernet0/0 1.1.1.2

*Mar 1 02:19:36.839: OSPF: End of hello processing

*Mar 1 02:19:36.867: OSPF: rcv. v:2 t:2 l:92 rid:1.1.1.2

aid:0.0.0.0 chk:3E70 aut:0 auk: from FastEthernet0/0

*Mar 1 02:19:36.867: OSPF: Rcv DBD from 1.1.1.2 on FastEthernet0/0 seq 0x212D opt 0x52 flag 0x3 len 92 mtu 1500 state EXCHANGE

*Mar 1 02:19:36.871: OSPF: Send DBD to 1.1.1.2 on FastEthernet0/0 seq 0x212D opt 0x52 flag 0x0 len 32

*Mar 1 02:19:36.887: OSPF: rcv. v:2 t:2 l:32 rid:1.1.1.2

aid:0.0.0.0 chk:82CF aut:0 auk: from FastEthernet0/0

*Mar 1 02:19:36.887: OSPF: Rcv DBD from 1.1.1.2 on FastEthernet0/0 seq 0x212E opt 0x52 flag 0x1 len 32 mtu 1500 state EXCHANGE

*Mar 1 02:19:36.891: OSPF: Exchange Done with 1.1.1.2 on FastEthernet0/0

*Mar 1 02:19:36.891: OSPF: Send LS REQ to 1.1.1.2 length 12 LSA count 1

*Mar 1 02:19:36.891: OSPF: Send DBD to 1.1.1.2 on FastEthernet0/0 seq 0x212E opt 0x52 flag 0x0 len 32

*Mar 1 02:19:36.895: OSPF: rcv. v:2 t:3 l:36 rid:1.1.1.2

aid:0.0.0.0 chk:F7D0 aut:0 auk: from FastEthernet0/0

*Mar 1 02:19:36.899: OSPF: Rcv LS REQ from 1.1.1.2 on FastEthernet0/0 length 36 LSA count 1

*Mar 1 02:19:36.899: OSPF: Sending update on FastEthernet0/0 to 1.1.1.2 Area 0

*Mar 1 02:19:36.899: OSPF: Send Type 1, LSID 1.1.1.1, Adv rtr 1.1.1.1, age 30, seq 0x80000007 (0)

*Mar 1 02:19:36.903: OSPF: Send UPD to 1.1.1.2 on FastEthernet0/0 length 40 LSA count 1

*Mar 1 02:19:36.911: OSPF: rcv. v:2 t:4 l:52 rid:1.1.1.2

aid:0.0.0.0 chk:1777 aut:0 auk: from FastEthernet0/0

*Mar 1 02:19:36.911: OSPF: Rcv LS UPD from 1.1.1.2 on FastEthernet0/0 length 52 LSA count 1

*Mar 1 02:19:36.915: OSPF: received update from 1.1.1.2, FastEthernet0/0

*Mar 1 02:19:36.915: OSPF: Rcv Update Type 1, LSID 1.1.1.2, Adv rtr 1.1.1.2, age 49, seq 0x80000007

*Mar 1 02:19:36.915: OSPF: Detect change in LSA type 1, LSID 1.1.1.2, from 1.1.1.2 area 0

*Mar 1 02:19:36.915: OSPF: Synchronized with 1.1.1.2 on FastEthernet0/0, state FULL

*Mar 1 02:19:36.915: %OSPF-5-ADJCHG: Process 1, Nbr 1.1.1.2 on FastEthernet0/0 from LOADING to FULL, Loading Done ###ADJ Build###

*Mar 1 02:19:36.915: OSPF: Schedule SPF in area 0

Change in LS ID 1.1.1.2, LSA type R, , spf-type Full

*Mar 1 02:19:37.275: OSPF: rcv. v:2 t:4 l:76 rid:1.1.1.2

aid:0.0.0.0 chk:4066 aut:0 auk: from FastEthernet0/0

*Mar 1 02:19:37.275: OSPF: Rcv LS UPD from 1.1.1.2 on FastEthernet0/0 length 76 LSA count 1

*Mar 1 02:19:37.279: OSPF: received update from 1.1.1.2, FastEthernet0/0

*Mar 1 02:19:37.279: OSPF: Rcv Update Type 1, LSID 1.1.1.2, Adv rtr 1.1.1.2, age 1, seq 0x80000008

*Mar 1 02:19:37.279: OSPF: Detect change in LSA type 1, LSID 1.1.1.2, from 1.1.1.2 area 0

*Mar 1 02:19:37.283: OSPF: Schedule SPF in area 0

Change in LS ID 1.1.1.2, LSA type R, , spf-type Full

*Mar 1 02:19:37.415: OSPF: For next LSA generation - wait : 5000ms next: 5000ms

*Mar 1 02:19:37.415: OSPF: Inc retrans unit nbr count index 1 (0/1) to 1/1

*Mar 1 02:19:37.415: OSPF: Set Nbr 1.1.1.2 1 first flood info from 0 (0) to 64D8D454 (5)

*Mar 1 02:19:37.415: OSPF: Init Nbr 1.1.1.2 1 next flood info to 64D8D454

*Mar 1 02:19:37.419: OSPF: Add Type 1 LSA ID 1.1.1.1 Adv rtr 1.1.1.1 Seq 80000008 to FastEthernet0/0 1.1.1.2 retransmission list

*Mar 1 02:19:37.419: OSPF: Start FastEthernet0/0 1.1.1.2 retrans timer

*Mar 1 02:19:37.419: OSPF: Set idb next flood info from 0 (0) to 64D8D454 (5)

*Mar 1 02:19:37.419: OSPF: Add Type 1 LSA ID 1.1.1.1 Adv rtr 1.1.1.1 Seq 80000008 to FastEthernet0/0 flood list

*Mar 1 02:19:37.423: OSPF: Sending update over FastEthernet0/0 without pacing

*Mar 1 02:19:37.423: OSPF: Flooding update on FastEthernet0/0 to 224.0.0.5 Area 0

*Mar 1 02:19:37.423: OSPF: Send Type 1, LSID 1.1.1.1, Adv rtr 1.1.1.1, age 1, seq 0x80000008 (0)

*Mar 1 02:19:37.423: OSPF: Create retrans unit 0x658F6BA8/0x6430C3AC 1 (0/1) 1

*Mar 1 02:19:37.423: OSPF: Set nbr 1 (0/1) retrans to 4695 count to 0

*Mar 1 02:19:37.427: OSPF: Set idb next flood info from 64D8D454 (5) to 0 (0)

*Mar 1 02:19:37.427: OSPF: Remove Type 1 LSA ID 1.1.1.1 Adv rtr 1.1.1.1 Seq 80000008 from FastEthernet0/0 flood list

*Mar 1 02:19:37.427: OSPF: Stop FastEthernet0/0 flood timer

*Mar 1 02:19:37.427: OSPF: Schedule SPF in area 0

Change in LS ID 1.1.1.1, LSA type R, , spf-type Full

*Mar 1 02:19:37.431: OSPF: Build router LSA for area 0, router ID 1.1.1.1, seq 0x80000008

*Mar 1 02:19:38.459: OSPF: Send hello to 224.0.0.5 area 0 on FastEthernet0/0 from 1.1.1.1

*Mar 1 02:19:39.415: OSPF: Sending delayed ACK on FastEthernet0/0

*Mar 1 02:19:39.415: OSPF: Ack Type 1, LSID 1.1.1.2, Adv rtr 1.1.1.2, age 49, seq 0x80000007

*Mar 1 02:19:39.415: OSPF: Ack Type 1, LSID 1.1.1.2, Adv rtr 1.1.1.2, age 1, seq 0x80000008

*Mar 1 02:19:39.443: OSPF: rcv. v:2 t:5 l:64 rid:1.1.1.2

aid:0.0.0.0 chk:6C59 aut:0 auk: from FastEthernet0/0

*Mar 1 02:19:39.443: OSPF: Received ACK from 1.1.1.2 on FastEthernet0/0

*Mar 1 02:19:39.443: OSPF: Rcv Ack Type 1, LSID 1.1.1.1, Adv rtr 1.1.1.1, age 30, seq 0x80000007

*Mar 1 02:19:39.447: OSPF: Rcv Ack Type 1, LSID 1.1.1.1, Adv rtr 1.1.1.1, age 1, seq 0x80000008

*Mar 1 02:19:39.447: OSPF: Dec retrans unit nbr count index 1 (0/1) to 0/0

*Mar 1 02:19:39.447: OSPF: Free nbr retrans unit 0x658F6BA8/0x6430C3AC 0 total 0. Also Free nbr retrans block

*Mar 1 02:19:39.451: OSPF: Set Nbr 1.1.1.2 1 first flood info from 64D8D454 (5) to 0 (0)

*Mar 1 02:19:39.451: OSPF: Adjust Nbr 1.1.1.2 1 next flood info to 0

*Mar 1 02:19:39.451: OSPF: Remove Type 1 LSA ID 1.1.1.1 Adv rtr 1.1.1.1 Seq 80000008 from 1.1.1.2 retransmission list

*Mar 1 02:19:39.451: OSPF: Stop nbr 1.1.1.2 retransmission timer

*Mar 1 02:19:41.915: OSPF: running SPF for area 0, SPF-type Full

*Mar 1 02:19:41.915: OSPF: Initializing to run spf

*Mar 1 02:19:41.915: OSPF - spf_intra() - rebuilding the tree

*Mar 1 02:19:41.915: It is a router LSA 1.1.1.1. Link Count 2

*Mar 1 02:19:41.915: Processing link 0, id 1.1.1.2, link data 1.1.1.1, type 1, cost 10

*Mar 1 02:19:41.919: Add better path to LSA ID 1.1.1.2, gateway 1.1.1.2, dist 10

*Mar 1 02:19:41.919: OSPF: putting LSA on the clist LSID 1.1.1.2, Type 1, Adv Rtr. 1.1.1.2

*Mar 1 02:19:41.919: Add path: next-hop 1.1.1.2, interface FastEthernet0/0

*Mar 1 02:19:41.919: Processing link 1, id 1.1.1.0, link data 255.255.255.252, type 3, cost 10

*Mar 1 02:19:41.923: Add better path to LSA ID 1.1.1.3, gateway 1.1.1.0, dist 10

*Mar 1 02:19:41.923: Add path: next-hop 1.1.1.1, interface FastEthernet0/0

*Mar 1 02:19:41.923: OSPF: downheap LSA on the clist LSID 1.1.1.2, Type 1, Adv Rtr. 1.1.1.2,

from index 1 to index 1

*Mar 1 02:19:41.923: OSPF: insert route list LS ID 1.1.1.2, type 1, adv rtr 1.1.1.2

*Mar 1 02:19:41.927: It is a router LSA 1.1.1.2. Link Count 2

*Mar 1 02:19:41.927: Processing link 0, id 1.1.1.1, link data 1.1.1.2, type 1, cost 10

*Mar 1 02:19:41.927: Ignore newdist 20 olddist 0

*Mar 1 02:19:41.927: Processing link 1, id 1.1.1.0, link data 255.255.255.252, type 3, cost 10

*Mar 1 02:19:41.931: Add better path to LSA ID 1.1.1.3, gateway 1.1.1.0, dist 20

*Mar 1 02:19:41.931: Add path: next-hop 1.1.1.2, interface FastEthernet0/0

*Mar 1 02:19:41.931: OSPF: Adding Stub nets

*Mar 1 02:19:41.931: OSPF: delete lsa id 1.1.1.3, type 0, adv rtr 1.1.1.1 from delete list

*Mar 1 02:19:41.935: OSPF: insert route list LS ID 1.1.1.3, type 0, adv rtr 1.1.1.1

*Mar 1 02:19:41.935: OSPF: Schedule SPF in area 0

Change in LS ID 1.1.1.2, LSA type X, spf-type Prefix Recalculation

*Mar 1 02:19:41.935: OSPF: Entered old delete routine area 0

*Mar 1 02:19:41.935: OSPF: ospf_gen_asbr_sum_all_areas

*Mar 1 02:19:41.935: OSPF: running spf for summaries area 0

*Mar 1 02:19:41.939: OSPF: sum_delete_old_routes area 0

*Mar 1 02:19:41.939: OSPF: Started Building Type 5 External Routes

*Mar 1 02:19:41.939: OSPF: Start processing Type 5 External LSA 100.0.0.1, mask 255.255.255.255, adv 1.1.1.2, age 360, seq 0x80000001, metric 20, metric-type 2 ###ROUTE LEARNED OF 100.0.0.1###

*Mar 1 02:19:41.939: Add better path to LSA ID 100.0.0.1, gateway 1.1.1.2, dist 20

*Mar 1 02:19:41.939: Add path: next-hop 1.1.1.2, interface FastEthernet0/0

*Mar 1 02:19:41.939: network update dest_addr 100.0.0.1 mask 255.255.255.255 gateway 1.1.1.2

*Mar 1 02:19:41.939: Add External Route to 100.0.0.1. Metric: 20, Next Hop: 1.1.1.2

*Mar 1 02:19:41.939: OSPF: insert route list LS ID 100.0.0.1, type 5, adv rtr 1.1.1.2

*Mar 1 02:19:41.939: OSPF: ex_delete_old_routes

*Mar 1 02:19:41.939: OSPF: Started Building Type 7 External Routes

*Mar 1 02:19:41.939: OSPF: ex_delete_old_routes

*Mar 1 02:19:46.751: OSPF: rcv. v:2 t:1 l:48 rid:1.1.1.2

aid:0.0.0.0 chk:E799 aut:0 auk: from FastEthernet0/0

*Mar 1 02:19:46.751: OSPF: Rcv hello from 1.1.1.2 area 0 from FastEthernet0/0 1.1.1.2

*Mar 1 02:19:46.751: OSPF: End of hello processing

*Mar 1 02:19:48.459: OSPF: Send hello to 224.0.0.5 area 0 on FastEthernet0/0 from 1.1.1.1

Hope this helps

Please rate useful posts and remember to mark any solved questions as answered. Thank you.

Please rate useful posts & remember to mark any solved questions as answered. Thank you.