Re: MPLS TE Tunnel : Tunnel B/W doubt

There can be multiple tunnels between a given src and a given dest.
If all properties of tunnel are same .... This will result in equal path
load balancing
If properties like b/w are diff .... Unequal path load balancing will take
place ..

On Sun, Jan 29, 2012 at 11:02 PM, CCIE KID <eliteccie_at_gmail.com> wrote:

> Sonu
>
> But the Head end Router l will choose only one path to the same Tail End
> Router with only one Tunnel. Why it chooses two Tunnels ?
>
>
>
> On Sun, Jan 29, 2012 at 10:12 PM, Sonu Khandelwal <sonu.kwl_at_gmail.com>wrote:
>
>> Yes, for two path to the same destination two tunnels will be needed with
>> two different explicit path.
>>
>> "tunnel mpls traffic-eng autoroute metric" to used to change the igp
>> metric of the tunnel interface. By default tunnel's igp metric is the same
>> as igp metric b/w source and destination.
>>
>> for e.g
>>
>> if tunnel source is 1.1.1.1 and tunnel destination is 3.3.3.3. Assume
>> tunnel is not present and cost to reach from 1.1.1.1 to 3.3.3.3 is 10.
>>
>> Now when tunnel comes up, its metric will be 10.
>>
>> if you want this metric of 10 to be changed then you can use "tunnel
>> mpls traffic-eng autoroute metric" to do the same thing.
>>
>> Thanks,
>> Sonu
>>
>>
>> On Sun, Jan 29, 2012 at 9:27 PM, CCIE KID <eliteccie_at_gmail.com> wrote:
>>
>>> Gaurav
>>>
>>> Dude one new doubt man
>>>
>>> To reach a particular Tail end router, there should be only route.
>>>
>>> In regular SPF, the result of path computation may be two equal cost
>>> multipaths (ECMP) to a destination. However, the result of CSPF is always
>>> one path to the tailend router. In case, two paths are equal, CSPF has 3
>>> rules followed sequentially to break the tie:
>>>
>>> *a.* Take the path with largest minimum available bandwidth
>>>
>>> *b.* Take the path with the lowest hop-count (number of routers in the
>>> path)
>>>
>>> *c.* Take one path at random.
>>>
>>>
>>> So there should be only one path to a TAIL END router.. How does it has
>>> two paths for a same TAILEND router. via two different TE TUNNELS.
>>>
>>>
>>>
>>> On Sun, Jan 29, 2012 at 8:44 PM, CCIE KID <eliteccie_at_gmail.com> wrote:
>>>
>>>> Gaurav
>>>>
>>>> Tats gr8 mate .. I will also check the purpose of it and let u know
>>>> buddy..
>>>> Till then study hard
>>>>
>>>>
>>>>
>>>> On Sun, Jan 29, 2012 at 8:33 PM, GAURAV MADAN <
>>>> gauravmadan1177_at_gmail.com> wrote:
>>>>
>>>>> Kid
>>>>>
>>>>> Everything you said is exactly what i understand this topic :)
>>>>> We are on same page .
>>>>>
>>>>> I will simulate the usage of metric command and try to post results ,
>>>>>
>>>>> Till then .. thnx
>>>>>
>>>>> Gaurav Madan
>>>>>
>>>>>
>>>>> On Sun, Jan 29, 2012 at 7:39 PM, CCIE KID <eliteccie_at_gmail.com> wrote:
>>>>>
>>>>>> Gaurav
>>>>>>
>>>>>> TE Auto Route Announce will just make ur OSPF learned LSA's from the
>>>>>> Tunnel Tail End to utitlize the Tunnel path to reach all the networks
>>>>>> behind the Tunnel Tail End Router. It has nothing to do with priority
>>>>>> levels for each tunnel
>>>>>> U can assign priorities to each tunnel and then tat take over the
>>>>>> appropriate B.W. available in the interface if it has highest priority
>>>>>>
>>>>>> In ur case both ur tunnels has both set up and hold priority has 7
>>>>>> and 7
>>>>>> 7 and 7 is the least priority tat u can assign to a tunnel and both
>>>>>> the tunnels has the same priority and both r pointing to the same tunnel
>>>>>> tail end and also u r running Auto Route Announce on both the tunnels
>>>>>>
>>>>>> But the only difference between the two tunnels is the Bandwidth and
>>>>>> to form the two tunnels it requires 60 and 70 kbps end to end to form the
>>>>>> tunnel. So atleast the B.W of the end to end path should be atleast 130kpbs
>>>>>>
>>>>>> So now OSPF will carry the TE information like the requested B.W and
>>>>>> also other TE colors associated with TE in its Opaque LSA Type 9 ,10 and
>>>>>> 11. depends upon it is a Single Area OSPF or Multi Area and also it is
>>>>>> within the Single AS. If the Head end sees that it has enough B.W. then the
>>>>>> Path message from Head end to Tail End and Reserve message from the Tail
>>>>>> End to head End is succesfull , the tunnel will be up.
>>>>>>
>>>>>> if there is any change in the available BW in that particular end to
>>>>>> end path, it will be conveyed by OSPF and it triggers the Path message and
>>>>>> Reserve message
>>>>>>
>>>>>> In ur setup
>>>>>>
>>>>>> U r obviously u r going to see two paths to reach the tail-end router
>>>>>> via these two tunnels and there will be Unequal cost LOAD balancing . If u
>>>>>> want to prioritize one tunnel over another one , just change the metric of
>>>>>> the tunnel rather than the BW
>>>>>> Because B.W inside the tunnel doesnt reflect ur BEST METRIC to reach
>>>>>> a particular TE Tail End
>>>>>>
>>>>>> So ultimately u have many paths to the Same tail end router ie via
>>>>>> different tunnels.So ultimately it all depends upon how much BW is required
>>>>>> to form the tunnel . Int his case , there will 70:60 ratio of traffic going
>>>>>> from one tunnel to another tunnel.
>>>>>>
>>>>>> If u dont want to see Unequal Cost Load Balancing, u have to do
>>>>>> Policy Routing rather than using AutoRoute Announce.
>>>>>>
>>>>>> But I am not sure about this command
>>>>>>
>>>>>> tunnel mpls traffic-eng autoroute metric
>>>>>>
>>>>>> If u give this command whether one tunnel will be preferred over
>>>>>> another tunnel if ur Tail End Router address are same.
>>>>>>
>>>>>> Post me about this command dude
>>>>>>
>>>>>> Hope this helps
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> On Sun, Jan 29, 2012 at 1:24 AM, Naveen <navin.ms_at_gmail.com> wrote:
>>>>>>
>>>>>>> Yes. What you have is already doing UELB (unequal cost load
>>>>>>> balancing in
>>>>>>> the ratio 6:7) also across TE tunnels. Try sending some traffic end
>>>>>>> to end,
>>>>>>> and check the TE counters.
>>>>>>>
>>>>>>> If your intention is not to load balancing at all, then remove
>>>>>>> "autoroute
>>>>>>> announce", and then route traffic to the tunnel you want with a local
>>>>>>> policy.
>>>>>>>
>>>>>>>
>>>>>>> On Sat, Jan 28, 2012 at 11:31 AM, GAURAV MADAN <
>>>>>>> gauravmadan1177_at_gmail.com>wrote:
>>>>>>>
>>>>>>> > Naveen ,
>>>>>>> >
>>>>>>> > Thnx for the reply ..
>>>>>>> > Do you mean to suggest some kind of unequal load-balancing across
>>>>>>> various
>>>>>>> > TE tunnels .
>>>>>>> >
>>>>>>> > Between the tunnels ; I can choose using following command :
>>>>>>> >
>>>>>>> > Router(config-if)#tunnel mpls traffic-eng autoroute metric
>>>>>>> >
>>>>>>> > I can set one tunnel as lower metric to be announced over the
>>>>>>> second
>>>>>>> > tunnel . and hence play around with this
>>>>>>> >
>>>>>>> > Is that what u r suggesting ?
>>>>>>> >
>>>>>>> >
>>>>>>> > Gaurav Madan
>>>>>>> >
>>>>>>> >
>>>>>>> >
>>>>>>> > On Sun, Jan 29, 2012 at 12:32 AM, Naveen <navin.ms_at_gmail.com>
>>>>>>> wrote:
>>>>>>> >
>>>>>>> >> What you are seeing is Load balancing across multiple TE tunnels
>>>>>>> for
>>>>>>> >> prefixes reachable further down the tunnel. This is an expected
>>>>>>> behavior
>>>>>>> >> with "autoroute announce". You can use "auto-bw" to dynamically
>>>>>>> control the
>>>>>>> >> TE tunnel Bandwidth after tunnel setup.
>>>>>>> >>
>>>>>>> >> Once tunnels are established (using CSPF), IGP considers the
>>>>>>> Tunnels as
>>>>>>> >> always 1-hop (and always prefers over any other IGP 1-hop path).
>>>>>>> You can
>>>>>>> >> load balance upto 8,16, or 32 TE paths as supported by the
>>>>>>> platform.
>>>>>>> >>
>>>>>>> >>
>>>>>>> >>
>>>>>>> >> On Sat, Jan 28, 2012 at 10:13 AM, Sonu Khandelwal <
>>>>>>> sonu.kwl_at_gmail.com>wrote:
>>>>>>> >>
>>>>>>> >>> [image: Boxbe] <https://www.boxbe.com/overview> Sonu
>>>>>>> Khandelwal (
>>>>>>> >>> sonu.kwl_at_gmail.com) is not on your Guest List<
>>>>>>> https://www.boxbe.com/approved-list>| Approve
>>>>>>> >>> sender <https://www.boxbe.com/anno?tc=10557674166_204049186> |
>>>>>>> Approve
>>>>>>> >>> domain <https://www.boxbe.com/anno?tc=10557674166_204049186&dom>
>>>>>>>
>>>>>>> >>>
>>>>>>> >>> on interface it means how much bandwidth can be reserved by RSVP.
>>>>>>> >>> on tunnel it means, how much bandwidth is required by tunnel.
>>>>>>> >>>
>>>>>>> >>> Hope it helps.
>>>>>>> >>>
>>>>>>> >>> Thanks,
>>>>>>> >>> Sonu
>>>>>>> >>>
>>>>>>> >>> On Sat, Jan 28, 2012 at 11:37 PM, GAURAV MADAN <
>>>>>>> >>> gauravmadan1177_at_gmail.com>wrote:
>>>>>>> >>>
>>>>>>> >>> > Then what does "rsvp bandwidth <> " on interface does ?
>>>>>>> >>> > That is also a constraint on interface to establish the tunnel
>>>>>>> ..
>>>>>>> >>> right ?
>>>>>>> >>> >
>>>>>>> >>> > How do you differentiate between the BW that we specify on
>>>>>>> interface
>>>>>>> >>> level
>>>>>>> >>> > and the one that we specify on interface tunnel ?
>>>>>>> >>> >
>>>>>>> >>> > Thnx
>>>>>>> >>> > Gaurav Madan
>>>>>>> >>> >
>>>>>>> >>> > On Sat, Jan 28, 2012 at 9:23 PM, Paul Negron <
>>>>>>> negron.paul_at_gmail.com>
>>>>>>> >>> > wrote:
>>>>>>> >>> >
>>>>>>> >>> > > The bandwidth is a constraint. It only says " I need 60K of
>>>>>>> >>> bandwidth in
>>>>>>> >>> > > order to establish this tunnel". One tunnel requires 60K and
>>>>>>> the
>>>>>>> >>> other
>>>>>>> >>> > > requires 70K. If the bandwidth is available for both, they
>>>>>>> will both
>>>>>>> >>> be
>>>>>>> >>> > > established. That "bandwidth" constraint has nothing to do
>>>>>>> with the
>>>>>>> >>> cost
>>>>>>> >>> > of
>>>>>>> >>> > > the tunnel for route selection.
>>>>>>> >>> > > --
>>>>>>> >>> > > Paul Negron
>>>>>>> >>> > > CCIE# 14856 CCSI# 22752
>>>>>>> >>> > > Senior Technical Instructor
>>>>>>> >>> > >
>>>>>>> >>> > >
>>>>>>> >>> > >
>>>>>>> >>> > > > From: GAURAV MADAN <gauravmadan1177_at_gmail.com>
>>>>>>> >>> > > > Reply-To: GAURAV MADAN <gauravmadan1177_at_gmail.com>
>>>>>>> >>> > > > Date: Sat, 28 Jan 2012 20:44:46 +0530
>>>>>>> >>> > > > To: Cisco certification <ccielab_at_groupstudy.com>
>>>>>>> >>> > > > Subject: MPLS TE Tunnel : Tunnel B/W doubt
>>>>>>> >>> > > >
>>>>>>> >>> > > > Hi All
>>>>>>> >>> > > >
>>>>>>> >>> > > > I am running in some issue to understand how Tunnel
>>>>>>> Bandwidth
>>>>>>> >>> works .
>>>>>>> >>> > > >
>>>>>>> >>> > > > Topology
>>>>>>> >>> > > > ---------
>>>>>>> >>> > > >
>>>>>>> >>> > > > R1 R4
>>>>>>> >>> > > > | |
>>>>>>> >>> > > > | |
>>>>>>> >>> > > > R2-----------------R3
>>>>>>> >>> > > >
>>>>>>> >>> > > > R1 is head end of tunnel . It has 2 tunnels Tunnel0 and
>>>>>>> Tunnel 1 as
>>>>>>> >>> > > follows
>>>>>>> >>> > > > :
>>>>>>> >>> > > >
>>>>>>> >>> > > > R1#sh run int tun 0
>>>>>>> >>> > > > Building configuration...
>>>>>>> >>> > > >
>>>>>>> >>> > > > Current configuration : 284 bytes
>>>>>>> >>> > > > !
>>>>>>> >>> > > > interface Tunnel0
>>>>>>> >>> > > > ip unnumbered Loopback0
>>>>>>> >>> > > > tunnel mode mpls traffic-eng
>>>>>>> >>> > > > tunnel destination 4.4.4.4
>>>>>>> >>> > > > tunnel mpls traffic-eng autoroute announce
>>>>>>> >>> > > > tunnel mpls traffic-eng priority 7 7
>>>>>>> >>> > > > tunnel mpls traffic-eng bandwidth 70
>>>>>>> >>> > > > tunnel mpls traffic-eng path-option 1 dynamic lockdown
>>>>>>> >>> > > > end
>>>>>>> >>> > > >
>>>>>>> >>> > > > R1#sh run int tun 1
>>>>>>> >>> > > > Building configuration...
>>>>>>> >>> > > >
>>>>>>> >>> > > > Current configuration : 284 bytes
>>>>>>> >>> > > > !
>>>>>>> >>> > > > interface Tunnel1
>>>>>>> >>> > > > ip unnumbered Loopback0
>>>>>>> >>> > > > tunnel mode mpls traffic-eng
>>>>>>> >>> > > > tunnel destination 4.4.4.4
>>>>>>> >>> > > > tunnel mpls traffic-eng autoroute announce
>>>>>>> >>> > > > tunnel mpls traffic-eng priority 7 7
>>>>>>> >>> > > > tunnel mpls traffic-eng bandwidth 60
>>>>>>> >>> > > > tunnel mpls traffic-eng path-option 1 dynamic lockdown
>>>>>>> >>> > > >
>>>>>>> >>> > > >
>>>>>>> >>> > > >
>>>>>>> >>> > > > Now ; one tunnel has bandwidth of 70Kbps and other has of
>>>>>>> 60Kbps .
>>>>>>> >>> > > > Following is my show ip route ospf output :
>>>>>>> >>> > > >
>>>>>>> >>> > > > 4.0.0.0/32 is subnetted, 1 subnets
>>>>>>> >>> > > > O 4.4.4.4 [110/4] via 4.4.4.4, 00:05:52, Tunnel1
>>>>>>> >>> > > > [110/4] via 4.4.4.4, 00:05:52, Tunnel0
>>>>>>> >>> > > >
>>>>>>> >>> > > > I see both entries there ...
>>>>>>> >>> > > >
>>>>>>> >>> > > > Is there a reason for this ?
>>>>>>> >>> > > > Please let me know .. I think that it should be routing
>>>>>>> via Tunnel
>>>>>>> >>> 0
>>>>>>> >>> > > only .
>>>>>>> >>> > > >
>>>>>>> >>> > > > Thanks
>>>>>>> >>> > > > Gaurav Madan
>>>>>>> >>> > > >
>>>>>>> >>> > > >
>>>>>>> >>> > > > Blogs and organic groups at http://www.ccie.net
>>>>>>> >>> > > >
>>>>>>> >>> > > >
>>>>>>> >>>
>>>>>>> _______________________________________________________________________
>>>>>>> >>> > > > Subscription information may be found at:
>>>>>>> >>> > > > http://www.groupstudy.com/list/CCIELab.html
>>>>>>> >>> >
>>>>>>> >>> >
>>>>>>> >>> > Blogs and organic groups at http://www.ccie.net
>>>>>>> >>> >
>>>>>>> >>> >
>>>>>>> _______________________________________________________________________
>>>>>>> >>> > Subscription information may be found at:
>>>>>>> >>> > http://www.groupstudy.com/list/CCIELab.html
>>>>>>> >>>
>>>>>>> >>>
>>>>>>> >>> Blogs and organic groups at http://www.ccie.net
>>>>>>> >>>
>>>>>>> >>>
>>>>>>> _______________________________________________________________________
>>>>>>> >>> Subscription information may be found at:
>>>>>>> >>> http://www.groupstudy.com/list/CCIELab.html
>>>>>>>
>>>>>>>
>>>>>>> Blogs and organic groups at http://www.ccie.net
>>>>>>>
>>>>>>>
>>>>>>> _______________________________________________________________________
>>>>>>> Subscription information may be found at:
>>>>>>> http://www.groupstudy.com/list/CCIELab.html
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>> With Warmest Regards,
>>>>>>
>>>>>> CCIE KID
>>>>>> CCIE#29992 (Security)
>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>
>>>>
>>>> --
>>>> With Warmest Regards,
>>>>
>>>> CCIE KID
>>>> CCIE#29992 (Security)
>>>>
>>>>
>>>>
>>>
>>>
>>> --
>>> With Warmest Regards,
>>>
>>> CCIE KID
>>> CCIE#29992 (Security)
>>>
>>>
>>>
>>
>
>
> --
> With Warmest Regards,
>
> CCIE KID
> CCIE#29992 (Security)

Blogs and organic groups at http://www.ccie.net
Received on Sun Jan 29 2012 - 23:14:23 ART