From: Maxim Kurushkin (m.kurushkin@orange-ftgroup.ru)
Date: Tue Mar 11 2008 - 04:53:30 ARST
Command distance 109 150.1.1.1 0.0.0.0 VIA_R1 works, for example, on
3640 Cisco IOS Software, 3600 Software (C3640-JS-M), Version 12.3(14)T7,
RELEASE SOFTWARE (fc2)
But doesnt work on latest IOSes.
From TAC: "After much deliberation the developers have decided that
they will not be changing this behavior. They are of the opinion the
distance command is not a valid way to change route selection within
OSPF and that OSPF metric such as cost, etc, should be used."
*R2:*
router ospf 1
area 0 range 139.1.0.0 255.255.255.0 cost 1000
area 0 range 139.1.2.0 255.255.255.0 cost 1000
area 0 range 139.1.6.0 255.255.255.0 cost 1000
area 0 range 139.1.7.0 255.255.255.0 cost 1000
area 0 range 139.1.11.0 255.255.255.0 cost 1000
Rack1R5#*show ip route ospf*
139.1.0.0/24 is subnetted, 12 subnets
O IA 139.1.11.0 [110/65] via 139.1.15.1, 00:19:18, Serial1/0.501
O IA 139.1.13.0 [110/128] via 139.1.15.1, 00:20:16, Serial1/0.501
O IA 139.1.2.0 [110/193] via 139.1.15.1, 00:19:15, Serial1/0.501
O IA 139.1.0.0 [110/138] via 139.1.15.1, 00:19:11, Serial1/0.501
O IA 139.1.6.0 [110/148] via 139.1.15.1, 00:19:05, Serial1/0.501
O IA 139.1.7.0 [110/139] via 139.1.15.1, 00:19:02, Serial1/0.501
O IA 139.1.23.0 [110/128] via 139.1.25.2, 00:20:16, Serial1/0.502
150.1.0.0/16 is variably subnetted, 6 subnets, 2 masks
O IA 150.1.7.7/32 [110/139] via 139.1.25.2, 00:20:16, Serial1/0.502
[110/139] via 139.1.15.1, 00:20:16, Serial1/0.501
O IA 150.1.6.6/32 [110/139] via 139.1.25.2, 00:20:16, Serial1/0.502
[110/139] via 139.1.15.1, 00:20:16, Serial1/0.501
O IA 150.1.3.3/32 [110/129] via 139.1.25.2, 00:20:16, Serial1/0.502
[110/129] via 139.1.15.1, 00:20:16, Serial1/0.501
O 150.1.2.2/32 [110/65] via 139.1.25.2, 00:20:16, Serial1/0.502
O 150.1.1.1/32 [110/65] via 139.1.15.1, 00:20:16, Serial1/0.501
Rack1R5#*show ip ospf database summary 139.1.0.0*
OSPF Router with ID (150.1.5.5) (Process ID 1)
Summary Net Link States (Area 1)
Routing Bit Set on this LSA
LS age: 71
Options: (No TOS-capability, DC, Upward)
LS Type: Summary Links(Network)
Link State ID: 139.1.0.0 (summary Network Number)
Advertising Router: 150.1.1.1
LS Seq Number: 80000002
Checksum: 0xEBDF
Length: 28
Network Mask: /24
TOS: 0 *Metric: 74 *
Routing Bit Set on this LSA
LS age: 1167
Options: (No TOS-capability, DC, Upward)
LS Type: Summary Links(Network)
Link State ID: 139.1.0.0 (summary Network Number)
Advertising Router: 150.1.2.2
LS Seq Number: 80000002
Checksum: 0x2CFB
Length: 28
Network Mask: /24
TOS: 0 *Metric: 1000 *
WBR,
Maxim Kurushkin
Carlos Alberto Trujillo Jimenez wrote:
> Hi Group.
>
> I solved task 3.7, but a different way from the Solution Guide that seems to
> be incorrect the answer in the solution guide.
>
>
> First, let remember what the task is asking:
>
> - Configure the OSPF domain in such a way that R5 uses R1 to get to VLAN
> 2,6,7,11 AN 367
> - In the case the frame relay circuit between R1 and R5 is down, this
> traffic should be rerouted to R2.
> - Don not use the ip ospf cost, bandwidth, virtual-link, stub, or nssa
> commands to accomplish this.
>
>
> My solution:
>
> In R2 I modified the cost of the area 0 networks that R2 is advertising to
> the area 1 (router 5 is memeber of area 1). As the restriction states to not
> use the command "IP OSPF COST", I modifyed the cost, but NOT USING THE
> COMMMAND "IP OSPF COST", so for me it seems my answer is ok, Im not
> violating any restriction.
>
> Router 2:
>
> router ospf 1
> area 1 range 139.1.2.0 255.255.255.0 cost 10000
> area 1 range 139.1.11.0 255.255.255.0 cost 10000
> area 1 range 139.1.0.0 255.255.255.0 cost 10000
> area 1 range 139.1.6.0 255.255.255.0 cost 10000
>
>
> As a result I cheekd R5 routing table and it has entries to vlans 2,6,7,11
> and 367 pointing to its prefered next hop R1 (router 1 is advertising the
> same networks as router 2, but with a better cost).
> I tested shutting down R1 link to the frame-relay network, and the routes
> are reachable now by its next hop R2.
>
>
>
> 2008/3/8, Herbert Maosa <asawilunda@googlemail.com>:
>
>> Hi Guys,
>>
>> I have tried to lab this again and again and my result seem to disagree
>> with
>> the solution to task 3.7 of IEWB lab 13. So either I may be missing
>> something very fundamental as the output from the solutions guide shows
>> that
>> it should work. So hopefully one of you can shed more light on my gaps
>> here.
>>
>> R1,R2,R6,SW1 ,R3a re originating VLANS 11, 2,6,7 and 367 respectively into
>> OSPF . R5 has adjacencies with R1 and R2 and recieving these prefixes. The
>> question is configure R5 such that it prefers the path towards R1 and only
>> use R2 as a backup.
>>
>> The solution is to lower the OSPF distance for these routes when they are
>> learned from R2.
>>
>> *distance 109 150.1.1.1 0.0.0.0 VIA_R1
>>
>> *VIA_R1 is a standard access-list that matches the desired routes.
>> 150.1.1.1is the ospf router-id of R1. Now, when I configure this way,
>> only VLAN 11 (
>> 139.1.0.0/24) has the distance lowered to 109 and R5 prefers this path
>> when
>> R1 is available. This is what I expect to happen and it is what I am
>> seeing
>> in the lab, as my understanding is that in the distance command above ,
>> 150.1.1.1 has to be the advertising router-id, and not the next hop from
>> which you learnt the LSA. So because R1 is only originating VLAN 11, it
>> seems to work that way, but the other routes are not affected even though
>> they are learnt from R1 because they are originated form somewhere else.
>>
>> Now, the show command output from the solutions guide seems to show all
>> these prefixes with their distance changed to 109, which is suggesting
>> that
>> the 150.1.1.1 in the distance command would be the router-id of the
>> next-hop
>> router that you learnt the prefixes from, and not necessarily the
>> advertising router.
>>
>> Can someone open my eyes here ? I have tried to find my own asnwer by
>> labbing this over and over again and I can not reproduce the solution
>> provided, even if I copy and paste the config from the solutions guide
>> as-is.
>>
>> Herbert.
>>
>> _______________________________________________________________________
>> Subscription information may be found at:
>> http://www.groupstudy.com/list/CCIELab.html
>>
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html
>
>
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