From: Brian Dennis (bdennis@internetworkexpert.com)
Date: Fri Sep 07 2007 - 02:05:35 ART
Brian,
In regards to your lesson on the hello timers issue here is a post that I
made to the list a while back.
By adjusting the hello/dead timers you can make non-compatible OSPF
network types appear as neighbors via the "show ip ospf neighbor" but they
won't become "adjacent" with each other. OSPF network types that use a DR
(broadcast and non-broadcast) can neighbor with each other and function
properly. Likewise OSPF network types (point-to-point and
point-to-multipoint) that do not use a DR can neighbor with each other and
function properly. But if you mix DR types with non-DR types they will
not function properly (i.e. not fully adjacent). You should see in the
OSPF database "Adv Router is not-reachable" messages when you've mixed DR
and non-DR types.
Here is what will work:
Broadcast to Broadcast
Non-Broadcast to Non-Broadcast
Point-to-Point to Point-to-Point
Point-to-Multipoint to Point-to-Multipoint
Broadcast to Non-Broadcast (adjust hello/dead timers)
Point-to-Point to Point-to-Multipoint (adjust hello/dead timers)
HTH,
Brian Dennis, CCIE4 #2210 (R&S/ISP-Dial/Security/SP)
bdennis@internetworkexpert.com
Internetwork Expert, Inc.
http://www.InternetworkExpert.com
Toll Free: 877-224-8987
Direct: 775-745-6404 (Outside the US and Canada)
>----- Original Message -----
Subject: RE: OSPF Virtual Link Troubles
Date: Thu, September 6, 2007 21:07
From: "brian pitts" <pittsbrian21@hotmail.com>
> All,
>
> I finaly figured it out. link types were different.
>
> On the connected link between r2 and r5. One was setup as a network
type of
> point-to-point while the other one was setup as broadcast. I think I dug
> myself my own rat hole on this one, because at the begining when I
initially
> configured OSPF I hade problems with router adjacencies and when I
debuged I
> saw mis-matches hello timeers so I changed the hello timers instead of the
> type of network link it was so it totally missed up the virtual links
when I
> had to configure them.
>
> Lesson learn 1 - when you see miss-matched hello timers look at the type of
> link it is first. Then change the link type to change the hello timers.
:-)
>
> Thanks,
>
> Brian
>
>
> > From: pittsbrian21@hotmail.com> To: mounir.mohamed@gmail.com> CC:
> ccielab@groupstudy.com> Subject: RE: OSPF Virtual Link Troubles> Date:
Thu, 6
> Sep 2007 20:25:50 -0500> > Sure,> > > Also when I do a debug ip ospf eve
and
> adj I get this on r5 only when I put in> the command: area 25 virtual
2.2.2.2>
> When I do the same thing on r2 I get nothing.> > 10:17:42: OSPF: Build
router
> LSA for area 0, router ID 5.5.5.5, seq> 0x80000001> > > r5#sho runBuilding
> configuration...> Current configuration : 913 bytes!version 12.1no service>
> single-slot-reload-enableservice timestamps debug uptimeservice timestamps
> log> uptimeno service password-encryption!hostname r5ip
subnet-zero!interface>
> Loopback0 ip address 5.5.5.5 255.255.255.0!interface Loopback1 ip address>
> 51.5.5.5 255.255.255.0!interface Ethernet0 ip address 150.50.57.5>
> 255.255.255.128!interface Serial0 ip address 150.50.25.5 255.255.255.0>
> encapsulation frame-relay ip ospf hello-interval 10 frame-relay map ip>
> 150.50.25.2 501 broadcast frame-relay map ip 150.50.25.5 501 no
frame-relay>
> inverse-arp!interface Serial1 ip address 150.50.9.5 255.255.255.192!router>
> ospf 1 router-id 5.5.5.5 log-adjacency-changes area 25 virtual-link
2.2.2.2>
> network 150.50.25.5 0.0.0.0 area 25 network 150.50.57.5 0.0.0.0 area 57!ip>
> classlessip http server!!line con 0 privilege level 15line aux 0line vty
0 4>
> login!end> > r5#sho ip ospf database> OSPF Router with ID (5.5.5.5)
(Process
> ID 1)> Router Link States (Area 25)> Link ID ADV Router Age Seq# Checksum
> Link> count2.2.2.2 2.2.2.2 1541 0x8000000B 0xA40B 25.5.5.5> 5.5.5.5 1452
> 0x80000006 0xDB20 1> Summary Net Link States (Area 25)> Link ID ADV
Router Age
> Seq# Checksum150.50.1.0> 2.2.2.2 802 0x80000008 0x481A150.50.12.0
2.2.2.2> 802
> 0x80000008 0xC493150.50.246.0 2.2.2.2 548> 0x8000000A 0x210B> Router Link
> States (Area 57)> Link ID ADV Router Age Seq# Checksum Link> count5.5.5.5
> 5.5.5.5 1452 0x80000017 0xDEFC 17.7.7.7> 7.7.7.7 634 0x80000390 0x66E6
1> Net
> Link States (Area 57)> Link ID ADV Router Age Seq# Checksum150.50.57.7>
> 7.7.7.7 634 0x80000014 0xD779> Type-5 AS External Link States> Link ID ADV
> Router Age Seq# Checksum Tag150.50.8.0> 81.8.8.8 627 0x80000386 0x73EA
0> > >
> > > > Date: Fri, 7 Sep 2007 03:04:33 +0200From:
mounir.mohamed@gmail.comTo:>
> pittsbrian21@hotmail.comSubject: Re: OSPF Virtual Link TroublesCC:>
> ccielab@groupstudy.comCould you share the running config of R5 or at least
> the> output of Show ip ospd database ofr R5.> On 9/7/07, brian pitts
> <pittsbrian21@hotmail.com> wrote:> All,This is my first time using this
and I
> was wonder if I could get some help> ina matter I'm having in my test
> lab..preparing for my CCIE R/S. I have a> network topology consisting of
> multiple OSPF areas and 1 areas don'thave ties> to the backbone area so a
> Virtual link is needed. This is what> Ihave.(r2)--area0, area 25 and
area 246
> --- RID= 2.2.2.2||(r5)--area 25,> and area 57 ---
RID=5.5.5.5||(r7)--area 57
> --- RID= 7.7.7.7So what I'm> trying to do is use area 25 as my transit area
> and extend area 0 to r2 so that> r7 area 57 has a connection to the
backbone
> area 0.Creating a virtual link is> simeple so I don't know what I having
such
> trouble.For some reason I can not> get the Virtual Link interface to
come up.
> If I go to the r5 and do a sho ip> opsf you see the area 0 but says the
> interface isinactive. I have tried> changing RID and clearing the ospf
> process. Reloadingthe routers and many> other things with no avil.r2#router
> ospf 1 router-id 2.2.2.2> log-adjacency-changes area 25virtual-link 5.5.5.5
> network 150.50.12.2> 0.0.0.0 area 0 network 150.50.25.2 0.0.0.0 area
25network
> 150.50.246.2> 0.0.0.0 area 246 neighbor 150.50.246.6 priority 1neighbor
> 150.50.246.4> priority 1r2#sho ip ospf vVirtual Link OSPF_VL8 to router
> 5.5.5.5 is down Run> as demand circuit DoNotAge LSA allowed. Transit
area 25,
> Cost of using 65535> TransmitDelay is 1 sec, State DOWN, Timer intervals
> configured, Hello 10,> Dead 40,Wait 40, Retransmit 5r2#sho ip ospf
nNeighbor
> ID Pri State> Dead Time Address Interface1.1.1.1 1 FULL/DR 00:00:34>
> 150.50.12.1FastEthernet5.5.5.5 0 FULL/ - 00:00:38>
> 150.50.25.5Serial0/0.256.6.6.6 1 FULL/DR 00:01:59>
> 150.50.246.6Serial0/0.2464.4.4.4 1 FULL/DROTHER 00:01:47> 150.50.246.4
> Serial0/0.246r2#sho ip ospf Routing Process "ospf 1" with ID> 2.2.2.2
Supports
> only singleTOS(TOS0) routes Supports opaque LSA Supports> Link-local
Signaling
> (LLS) It is an area border router Initial SPF schedule> delay 5000 msecs
> Minimum hold timebetween two consecutive SPFs 10000 msecs> Maximum wait
time
> between twoconsecutive SPFs 10000 msecs Incremental-SPF> disabled
Minimum LSA
> interval 5 secs Minimum LSA arrival 1000 msecs LSA group> pacing timer 240
> secs Interfaceflood pacing timer 33 msecs Retransmission> pacing timer 66
> msecs Number ofexternal LSA 1. Checksum Sum 0x0193A2 Number of> opaque
AS LSA
> 0. Checksum Sum 0x000000 Number of DCbitless external and opaque> AS LSA 0
> Number of DoNotAgeexternal and opaque AS LSA 0 Number of areas in> this
router
> is 3. 3 normal 0stub 0 nssa External flood list length 0 Area> BACKBONE(0)
> Number of interfaces in this area is 2 Area has no> authentication
> SPFalgorithm last executed 02:12:52.992 ago SPF> algorithm executed 3
> timesArea ranges are Number of LSA 6. Checksum Sum> 0x057112 Number of
opaque
> link LSA 0. Checksum Sum 0x000000> Number of DCbitless LSA 0Number of
> indication LSA 0 Number of DoNotAge> LSA 0 Flood listlength 0 Area 25
Number
> of interfaces in this> area is 1 Area has no authentication SPF
algorithm last
> executed> 01:53:35.632 agoSPF algorithm executed 7 times Area ranges are>
> Number of LSA 5.Checksum Sum 0x045850 Number of opaque link LSA 0.>
Checksum
> Sum 0x000000 Number of DCbitless LSA 0 Number of> indication LSA 0Number of
> DoNotAge LSA 0 Flood list length 0 Area> 246 Numberof interfaces in this
area
> is 1 Area has no> authentication SPF algorithm last executed
03:19:39.440 ago
> SPF> algorithm executed 3 timesArea ranges are Number of LSA 8. Checksum
Sum>
> 0x073F16 Number ofopaque link LSA 0. Checksum Sum 0x000000> Number of
> DCbitless LSA 0 Number of indication LSA 0 Number of DoNotAge> LSA 0 Flood
> listlength 0r5#router ospf 1 router-id 5.5.5.5> log-adjacency-changes area
> 25virtual-link 2.2.2.2 network 150.50.25.5> 0.0.0.0 area 25
network150.50.57.5
> 0.0.0.0 area 57r5#sho ip ospf v Virtual> Link OSPF_VL2 to router 2.2.2.2 is
> down Run asdemand circuit DoNotAge LSA> allowed. Transit area 25, Cost of
> using 65535Transmit Delay is 1 sec, State> DOWN, Timer intervals
configured,
> Hello 10, Dead 40, Wait 40, Retransmit> 5r5#sho ip ospf nNeighbor ID Pri
State
> Dead Time> AddressInterface7.7.7.7 1 FULL/DR 00:00:32 150.50.57.7>
> Ethernet02.2.2.2 100 FULL/DR 00:00:37> 150.50.25.2Serial0r5#sho ip ospf
> Routing Process "ospf 1" with ID 5.5.5.5> Supports only singleTOS(TOS0)
routes
> Supports opaque LSA SPF schedule delay 5> secs, Hold timebetween two
SPFs 10
> secs Minimum LSA interval 5 secs. Minimum> LSA arrival 1secs Number of
> external LSA 4. Checksum Sum 0x20F88 Number of> opaque AS LSA 0.
Checksum Sum
> 0x0 Number of DCbitless external and opaque AS> LSA 0 Number ofDoNotAge
> external and opaque AS LSA 0 Number of areas in this> router is 3.
3normal 0
> stub 0 nssa External flood list length 0 Area> BACKBONE(0) (Inactive)
Number
> of interfaces in this area is 1> Area has noauthentication SPF algorithm
> executed 1 times Area> ranges areNumber of LSA 0. Checksum Sum 0x0
Number of
> opaque link LSA> 0. Checksum Sum 0x0 Number of DCbitless LSA 0 Number of>
> indication LSA 0Number of DoNotAge LSA 0 Flood list length 0 Area 25>
Numberof
> interfaces in this area is 1 Area has no authentication> SPF algorithm
> executed 20 times Area ranges are Number of LSA> 15.Checksum Sum 0x7B8E8
> Number of opaque link LSA 0. Checksum Sum> 0x0Number of DCbitless LSA 0
Number
> of indication LSA 0 Number> of DoNotAge LSA 0 Flood list length 0 Area 57
> Number> ofinterfaces in this area is 1 Area has no authentication>
> SPFalgorithm executed 12 times Area ranges are Number of LSA 8.>
Checksum Sum
> 0x554E1 Number of opaque link LSA 0. Checksum Sum> 0x0Number of
DCbitless LSA
> 0 Number of indication LSA 0 Number> ofDoNotAge LSA 0 Flood list length
0Also
> I'm not sure why the cost on> the virtual link would be 65535>
> Thanks,Brian_________________________________________________________________>
> ______Subscription information may be found>
> at:http://www.groupstudy.com/list/CCIELab.html -- Best Reagrds,Mounir
Mohamed>
> > _______________________________________________________________________>
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