OSPF opaque (MPLS-TE)

I have some question:
1.MPLS traffic engineering use opaque (LSA type 9,10,11) to get eg. BW of the link!
But in OSPF , when there is a change in an area, the LSA will flood to all. So if there is an application transfer a file on the link, the BW will change continuosly (?), so the LSA will flood and how can the CR-LDP know what information about BW on that link to use.
2.In an multi-area OSPF network, which router will start the label distribution process??
3.Is there any document about opaque with MPLS-TE. I try RFC3630 but it's very difficult to understand.

Hello,
MPLS TE is a pure control plane feature. So:
A1) The announced bandwidth does only change when there is a new "booking". This means that only when a new tunnel is routed over a link, when a tunnel is removed from a link or when a link up/down event occurs flooding is needed. To control the amount of opaque LSAs, thresholds are used for the booking bandwidth value.
The real bandwidth utilized at any moment in time is not taken into account by MPLS TE!
A2) Every MPLS TE enabled router will send LSA 10 and ABRs will insert this info into other areas. So pretty much LSA generation and flooding does not deviate from "normal" OSPF LSAs.
A3) I would also read "RFC 2370, The OSPF Opaque LSA Option".
Hope this helps! Please rate all posts.
Regards, Martin

Similar Messages

Understanding OSPF For MPLS Superbackbone.

LSA1 is Router LSA And LSA2 is Network LSA.What is the difference between them?In which direction are they propogated?I need to understand it neatly as I am studying it for MPLS Superbackbone .

In short, the router LSA is generated by all routers and describe all the connected interfaces on that router.
The network LSA is generated by the Designated Router (DR) only and describe all the routers connected to the broadcast or NBMA network for which this router is the DR.
If you need more information on what the LSA are for and the details of OSPF in general, I would recommend you read RFC2328.
Here's the link for it:
http://www.ietf.org/rfc/rfc2328.txt?number=2328
Hope this helps,

OSPF path MPLS/point to point

Hey Guys,
I have two links on my router;
R1 ----- MPLS -----R2 ------------------------------------------1st link
R1-----pt to pt -----R3------MPLS----R2 ---------------------2nd Link
by default I am using 1st link and I would like to move to 2nd link, can anyone help how do I do that ?

Disclaimer
The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.
Liability Disclaimer
In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.
Posting
From R1 to R2, correct? (R2 to R1 could be tricky - depends on how R2 interact with MPLS).
For R1 to R2, you could just set a direct (high) OSPF interface cost on the R1 port to MPLS.

MPLS network design questions

we have in our company 230 remote sites, and we are changing all of our circuits to MPLS. wondering if i need to get a high end router in our Data Center? currently we have 3925. also what is the best routing protocol to use in this kind of network? Eigrp or ospf? MPLS will be hosted by the service provider

I have found that the provider typically wants to know exactly what routes you will be advertising when using EIGRP or OSPF. This is something they will have to configure on their network to allow. For example EIGRP routes flow from Site A to Site B and you have a new subnet to use for an application. You put the proper network statements in EIGRP and are not learning routes on the other side. You would then have to fill out a form or call a support number to get your new network to the other side.
With BGP there is much more control over what you can advertise with adding networks. With 230 sites you will feel the benefit quickly if you start growing and adding subnets in data centers or additional sites.

Redundant link between two core sites with MPLS

Hi,
we have 50+ sites connected via MPLS. (see diagram)
Out core sites are SITE A (primary) & SITE B (secondary). These core sites are connected via a ptp link.
Both sites connect to the MPLS cloud via their own routers and all sites can reach SITE A & SITE B.
Now, if I pull the cable on SITE A's MPLS router, nothing can reach SITE A as expected.
Is it possible to get all of the MPLS sites to reach SITE A via SITE B's MPLS router and PtP link (and vice versa if SITE B's MPLS router went down)
Basically, redundancy if one of the MPLS routers went down at one of the core sites?

Hi,
yes, it's clearer now.
So what I'd think about would be running OSPF between the MPLS router and L3 switch on each site.
You would redistribute BGP prefixes to OSPF then.
And also configure a default route on the L3 switch pointing to the other L3 switch over the ptp line.
Plus keep the static routes for the other core site prefixes pointing to the other L3 switch over the ptp line.
That way:
1) Under normal conditions the L3 switch in site A will use a static route over ptp line (better AD than OSFP) to reach site B and vice versa.
2) In a case of MPLS router A failure:
The outging traffic from Site A would be routed via the ptp line to the L3 switch in site B (due to the default route). The L3 switch in site B will know the routes to the remote MPLS sites (received via OSPF from MPLS router B).
The incoming traffic will be received on the MPLS router B (due to prefixes for site A advertised from B with worse BGP attributes - but no prefixes advertised to MPLS from A). The MPLS router in Site B will use its static routes to forward the traffic to the L3 switch in site B. And the L3 switch will use its static routes for site A prefixes to forward the traffic over the ptp line.
Analogic routing will be applied in a case of MPLS router failure in site B.
3) In a case of the ptp line going Down:
The static routes should disapper from the routing tables on both L3 switches.
But they should still get the routes to the other core site received from OSPF (redistributed from BGP).
4) So the only problematic case might be the ptp line failing but the L3 switch interface remaining Up.
You might need to get either some tracking (not sure if available on L3 switches) or dynamic routing involved to overcome this.
Either running OSPF between the L3 switches or even runnig EIGRP to route the site A and B prefixes only possibly?
But I'm not sure if this wouldn't bring too much complexity to the design?
Best regards,
Milan

MPLS TE RSVP explicit problem

I have two routers connected in a lab via MPLS TE using RSVP. When i setup the tunnel to use explicit path-option
for example " tunnel mpls traffic-eng path-option 2 explicit identifier 2", the tunnel goes down and doesnt come up until i change it to use" tunnel mpls traffic-eng path-option 2 dynamic". Any ideas why this is not working?
R1
ip cef
mpls traffic-eng tunnels
interface Loopback0
ip address 150.1.1.1 255.255.255.255
interface Loopback1
description MPLS Traffic Eng
ip address 172.25.1.1 255.255.255.0
interface Tunnel0
ip unnumbered Loopback1
load-interval 30
tunnel destination 172.25.2.1
tunnel mode mpls traffic-eng
tunnel mpls traffic-eng autoroute announce
tunnel mpls traffic-eng priority 1 1
tunnel mpls traffic-eng bandwidth 100
tunnel mpls traffic-eng path-option 1 dynamic
interface Serial1/0
ip address 192.168.1.1 255.255.255.0
mpls traffic-eng tunnels
serial restart-delay 0
ip rsvp bandwidth 100
router ospf 1
mpls traffic-eng router-id Loopback1
mpls traffic-eng area 0
router-id 150.1.1.1
log-adjacency-changes
network 150.1.1.1 0.0.0.0 area 0
network 172.25.1.0 0.0.0.255 area 0
network 172.25.80.1 0.0.0.0 area 0
network 192.168.1.0 0.0.0.255 area 0
network 192.168.2.0 0.0.0.255 area 0
R2
ip cef
mpls traffic-eng tunnels
interface Loopback0
ip address 150.2.2.2 255.255.255.255
interface Loopback1
description MPLS Traffic Eng
ip address 172.25.2.1 255.255.255.0
interface Tunnel0
ip unnumbered Loopback1
tunnel destination 172.25.1.1
tunnel mode mpls traffic-eng
tunnel mpls traffic-eng autoroute announce
tunnel mpls traffic-eng priority 2 2
tunnel mpls traffic-eng bandwidth 200
tunnel mpls traffic-eng path-option 2 dynamic
interface Serial1/1
ip address 192.168.1.2 255.255.255.0
ip ospf priority 0
mpls traffic-eng tunnels
serial restart-delay 0
ip rsvp bandwidth 200
router ospf 1
mpls traffic-eng router-id Loopback1
mpls traffic-eng area 0
router-id 150.2.2.2
log-adjacency-changes
network 150.2.2.2 0.0.0.0 area 0
network 172.25.2.0 0.0.0.255 area 0
network 192.168.1.0 0.0.0.255 area 0

Hi,
Could you post the "show ip explicit-paths" output. I couldn't locate the explicit path identifier 2 config from your running-config. May be you missed to configure the explicit path?
Sample config for R1:
Router(config)#ip explicit-path identifier 2
Router(cfg-ip-expl-path)#next-address 192.168.1.2
Explicit Path identifier 2:
1: next-address 192.168.1.2
Router(cfg-ip-expl-path)#do show ip exp
PATH 2 (strict source route, path complete, generation 3)
1: next-address 192.168.1.2
Router(cfg-ip-expl-path)#
Thanks,
Vijay

Mpls-te vs performance routing (PFR)

Hello All,
Can someone tell me if MPLS-TE can use ip sla stats like PFR and is anyone using PFR in a enterprise (single AS) and redistrubing BGP to an IGP.
current we are using regular OSPF with Mpls looking for with smarter load balancing capability.
1. All traffic is voip
2. core is 7200 vxr's
any suggestions / links are appreciated
thanks
john

Hello John,
MPLS Te has its own signaling plane based on RSVP-TE and TE extensions of link state protocols.
So it doesn't use or interact with IP SLA.
to be noted that if you are in an MPLS scenario you don't need to redistribute BGP into OSPF.
the mpls forwarding for recursion follows the LSP path to the BGP next-hop (loopback or remote PE).
so if you multiple paths to BGP next-hop CEF based per destination load balancing using exor of IP SA, IP DA, and hash should already happens.
if you redistribute the BGP networks in IGP LDP will create additional LSPs for these IP subnets but the load balancing should not improve.
if you have two paths to BGP next hop you will have two paths to VOIP subnet
but using per packet load balancing has negative effects on jitter (delay variation)
Hope to help
Giuseppe

Disable BFD in multiple Router Sub interfaces that participates in OSPF

Hi team,
Please help me on this. Here is the scenario:
We are on an enterprise set up and running on 100+ routers.
We have 200 to 300+ sub interfaces for virtual circuits
Our protocol is OSPF over MPLS
One of our provider in LA encountered link flaps on SONET causing our LA router that is directly connected to that link to recalculate multiple times.
Recalculation of OSPF routes caused disconnection of users in LA VM's.
We were advised by our provider in LA to disable BFD so minor link flaps will no affect recalculation of routes.
We are now tasked by our design team to Disable BFD in multiple Router Sub interfaces that participates in OSPF.
My questions are:
What is the implication in disabling all BFD in routers' interface and sub interface?
Will this improve recalculation of OSPF routes in cause of link flaps or it will totally ignore the link flaps?
Will the routers only recognize a "full down" status of the interface?
How can we Disable BFD in multiple Router Sub interfaces that participates in OSPF in a faster way? Or do we have to do this one by one?
Please advise before we present this to the CAB and implementation. Thank you.

My questions are:
What is the implication in disabling all BFD in routers' interface and sub interface?
Answer: the implication would be eliminating sub-second millisecond convergence.
BFD detect failure at the link layer very fast , once detected it informs the upper layer protocol about the failure causing it to converge immediately.
Will this improve recalculation of OSPF routes in cause of link flaps or it will totally ignore the link flaps?
Answer: if your Provider experiencing intermittent flaps, then yes it will be advisable to turn BFD off. this however doesn't totally ignore the link flaps, once the upper protocol detect the failure based on the dead interval parameter on OSPF, it will recalculate OSPF routes again. Keep in mind, if you have redundant or more links to your provider , then I wouldn't recommend disabling BFD , as it should improve Convergence and you shouldn't notice the failure.
Will the routers only recognize a "full down" status of the interface?
Answer: disabling BFD allows the router recognize a full down status once the upper protocol dead interval occurs or full down status of interface. which ever occurs the earliest.
How can we Disable BFD in multiple Router Sub interfaces that participates in OSPF in a faster way? Or do we have to do this one by one?
You can disable it one by one. or if you have configuration management software, it allows you to do it for all nodes at a time. but this depends if you have it or not.
Please consider not to disable BFD if you have multiple OSPF links towards your provider from any branch, as it shouldn't impact your VMs, it should rather improve Convergence at milliseconds which is absolutely not noticeable.
BR,
Mohamed

Get the attribute_flags of the interface

Hi all,
Does anybody know how to get the value of the attribute_flags of a physical interface over which a MPLS Tunnel could traverse if the affinity bits are conformed?
I mean, when we configure with the next CLI command
Router(config-if)#mpls traffic-eng attribute-flags
the attribute-flags of an interface, that it will be later check to conform with the affinity configuration of the tunnel, How can I get the value of attribute-flags by querying a MIB? Which MIB?
Thanks to all.
Joan.

Hi,
my best bet would be 1.3.6.1.4.1.9.10.99, which is about OSPF opaque LSAs, they contain the relevant information. There is no MIB variable especially for the affinity bits on an interface as far as I know.
Hope this helps
Martin
Link: http://tools.cisco.com/Support/SNMP/do/BrowseOID.do?local=en&translate=Translate&objectInput=1.3.6.1.4.1.9.10.99

Database tool for routing table history changes

Dear Community, I'm looking for a freeware tool to hold history changes in routing tables for small to medium network running BGP, OSPF and MPLS VPN routing tables via VRFs. This tool need a way to compare the database in order to know if these are the same during the time.
Is there a way to do this in Cisco Works?
Thanks in advances for your recommendations.

Julius,
There are no industry recommended open source DB tools.
Normally it depends upon the developer preferences that how he/she wants to see the tool usability.
I can suggest you to go through the below link:
http://sourceforge.net/search/?type_of_search=soft&words=SQL+Tools
You can find many open source SQL tools, which you have to test and select one among them.
I can suggest you to use:
1) TOra
2) Easy SQL
3) SQuirrel
"Choose a Tool which is easy to use and efficient, Dont worry about Look n Feel"
Best of Luck

Policy based routing on VRF interfaces to route traffic through TE Tunnel

Hi All,
Is there a method to do policy based routing on VRF interfaces and route data traffic through one TE tunnel and non-data traffic through another TE tunnel.
The tunnel is already build up with these below config
interface Tunnel25
ip unnumbered Loopback0
tunnel destination 10.250.16.250
tunnel mode mpls traffic-eng
tunnel mpls traffic-eng path-option 10 explicit name test
ip explicit-path name test enable
next-address x.x.x.x
next-address y.y.y.y
router ospf 1
mpls traffic-eng router-id Loopback0
mpls traffic-eng area 0
mpls traffic-eng tunnels
nterface GigabitEthernet5/2
mpls traffic-eng tunnels
mpls ip
Is there additional config needed to work ,also in the destination end for the return traffic,we want to use the normal PATH --I mean non TE tunnel.
We tested with the above scenario,but couldn't able to reach the destination.Meantime we had a question,when the packet uses the policy map while ingress,it may not know the associatuion with VRF(Is that right? --If so ,how to make it happen)
Any help would be really appreciated
Thanks
Regards
Anantha Subramanian Natarajan

hi Anantha!
I might not be the right person to comment on your first question. I have not configured MVPNs yet and not very confertable with the topic.
But I am sure that if you read through the CBTS doc thoroughly, you might be able to derive the answer yourself. One thing I notice is that " a Tunnel will be selected regularly according to the routing process (even isf it is cbts enabled). From the tunnels selected using the regular best path selection, the traffic is mapped to a perticular tunnel in the group if specific class is mapped to that tunnel.
So a master tunnel can be the only tunnel between the 2 devices over which the routing (bgp next hops) are exchanged and all other tunnels can be members of this tunnel. So your RPF might not fail.
You might have to explore on this a bit more and read about the co-existance of multicast and TE. This will be the same as that.
For your second question, the answer would be easy :
If you want a specific eompls cust to take a particular tunnel/path, just create a seperate pair of loopbacks on the PEs. Make the loopback learnt on the remote PE through the tunnel/path that you want the eompls to take. Then establish the xconnect with this loopback. I am assuming that your question is that a particular eompls session should take a particular path.
If you meant that certain traffic from the same eompls session take a different path/tunnel, then CBTS will work.
Regards,
Niranjan

Route Leaking Issue

Hi All,
Still cutting my teeth with MPLS, and i am labbing up some stuff, and i've come accross an issue (or not)
This maybe by design, i'm not sure.
I've got a basic P core running OSPF and MPLS. Easy so far.
I've got 2 PEs, one on each side (still with me )
Attached to each PE I have a CE, and a Loopback.
On each side the CE is in one VRF and the Loopback is in another.
All straighforward so far. Routing is work I am using RIP for the CEs and Redisribute connected for the L-Backs.
MPBGP is working fine and the routes are being carried accross the core.
I now want to step it up and bit a try out some route leaking. I have imported routes from the CE VRF to the LBack VRF easily
on one PE. and vice versa.
However, the next step is where i get confused. When i import routes to a VRF i would expect to see them
propagated accross the MPLS core to the same VRF on the other side of the VPN.
Not sure if it should work like this.
Any Opinions??
Thank all
Stephen

Hi Stephen,
As per your senario you wnat to import the route from one vrf to other vrf , So to achive that you can configure route-target for same.
Below is the senario :
CE 1_A--------------                                                         ------------------- CE1_B
                           PE 1 ---------------- P ---------------- PE 2
CE 2_A--------------                                                         ------------------- CE 2_B
In above senario
1] CE1_A & CE 1_B are in CUST_A vrf .
2] CE2_A & CE 2_B are in CUST_B vrf .
Now If you want that in CE 1 _A that is in vrf CUST_A should communicate with only CE2_A that is in vrf CUST_B you ca have different RT , Below is the example for above senario.
PE1 -
ip vrf CUST_A
rd 65000:100
route-target export 65:100
route-target import 65:100
route-target import 65: 20
route-target export 65: 10
ip vrf CUST_B
rd 65000:200
route-target export 65:100
route-target import 65:100
route-target import 65: 10
route-target export 65: 20
Here in above config you can see that in CUST_A vrf we had export the RT 65: 10 & that RT is imported by CUST_B vrf & in CUST_B vrf you had exported 65:20 RT & that RT is imported by CUST_A vrf.
So in now you can see that in CE 1_A & CE 2_A will see each other route in there routing table . This is know as extramet in MPLS.
Regards
Chetan Kumar
http://chetanress.blogspot.com

Packet out of sequence Query

Hi, In our MPLS network we are planning two add one more WAN link between two nodes of same bw as of existing link, say two WAN link of 200Mbps. As a IGP we are running OSPF and MPLS enabled on the WAN. If the traffic gets load balance on both the parallel link then will the packet out of sequence issue appears ?
If this is introducing the packet out of sequence issue then is there any way to avoid the same but have to use both the wan link for the traffic flow.
Need the information
Regards,
Nilesh

Hello Nilesh,
load balancing is flow based also on an MPLS network.
Load balancing criteria of MPLS frames is based on internal MPLS label (VPN label) for MPLS L3 VPN service.
In any case, whatever is the type of MPLS service there will not be out of order issues as load balancing will be flow based and packets belonging to the same flow will be switched over the same path
Hope to help
Giuseppe

Considerations for L3/Internet VPN

Hi,
Can anyone please share their experiences regarding huge L3VPN deployments, want to know things like possible issues, considerations, feasibility and general technical challenges that I might face...
I am talking about VPN with 30+ sites...
Thanks
Sultan

Too add some more...
We are doing a very large (and complicated) roll out right now. Of couple of things we have run into that you might want to keep your heads up on.
1. Be sure all your VPN's, RD's, RT's are well documented. Know if your going to use complex VPNs, overlapping VPN's and what RT's you'll need and where.
2. I would use BGP Route Reflectors over a fully messed BGP backboone, however BB RRs will only advertise the best routes, you may need to use something to differentient your routes at times. For instance we have an Internet VPN coming from two different PEs, at times we want customers to use one Internet route at one PE versus the other. For the BGP RR to properly advertise two routes within the SAME VPN we need to use Different RD's and implement SOO.
3. Use the SOO extended community, you'll never know when you might need to act on prefixes for one reason or another.
4. Look into Cisco's IP Solution Center (ISC). At first I hated this prodcut (I tell my student's GUI's are for the week and timid..hehe). But this product can help rapidly deploy VPN, L2VPNs, Service request, TE and all kinds of good stuff. It's an expensive Service provider product. But it's pretty cool!
5. Use OSPF or IS-IS on the core. For your core IGP only use OSPF or IS-IS. These protocols will scale, and there are the only two that will support MPLS TE (traffic Engineering). OSPF and MPLS go hand in hand, the really do. The OSPF super backbone makes the area 0 problem go away. But watch for backdoor routes and stuff.
Food for thought....
Karl Solie

LDP Neighbor - Holdown / Discovery timer expired.

Hello,
I'm having an intermittent issue with LDP sessions dropping between one specific router and it's two peers.
Solution background:
We have 3 x 7201 (NPE-G2) running c7200p-spservicesk9-mz.150-1.M5.bin.
The routers are arranged in a "triangle" with a link to each router utilising G0/2 + 3 on each router, IGP is OSPF with all routers + loopbacks being in OSPF Area 0. OSPF RID + MPLS RID is Lo0.
Routers are called ABC-CORE-1, CCC-CORE-1, CBC-CORE1.
During the "outage" the DLP session between ABC->CBC remains constant without issue, however the LDP sessions with CCC-CORE1 both drop stating the following:
ABC-CORE-1#show log
Apr 3 17:30:40.236: %LDP-5-NBRCHG: LDP Neighbor 10.64.255.2:0 (1) is DOWN (Received error notification from peer: Holddown time expired)
Apr 3 17:30:44.180: %LDP-5-NBRCHG: LDP Neighbor 10.64.255.2:0 (1) is UP
CCC-CORE-1#show log
.Apr 3 17:30:39: %LDP-5-NBRCHG: LDP Neighbor 10.64.255.1:0 (1) is DOWN (Discovery Hello Hold Timer expired)
.Apr 3 17:30:43: %LDP-5-NBRCHG: LDP Neighbor 10.64.255.1:0 (3) is UP
Neighbor output:
CCC-CORE-1#sh mpls ldp neigh 10.64.255.1 det
    Peer LDP Ident: 10.64.255.1:0; Local LDP Ident 10.64.255.2:0
        TCP connection: 10.64.255.1.646 - 10.64.255.2.36718
        Password: not required, none, in use
        State: Oper; Msgs sent/rcvd: 1191/1192; Downstream; Last TIB rev sent 130
        Up time: 16:24:42; UID: 10; Peer Id 2;
        LDP discovery sources:
          GigabitEthernet0/2; Src IP addr: 10.64.0.1
            holdtime: 15000 ms, hello interval: 5000 ms
        Addresses bound to peer LDP Ident:
          10.64.2.1       192.168.128.126 10.64.0.1       10.64.0.5
          10.64.255.1     10.64.254.1
        Peer holdtime: 180000 ms; KA interval: 60000 ms; Peer state: estab
        Clients: Dir Adj Client
        Capabilities Sent:
          [Dynamic Announcement (0x0506)]
          [Typed Wildcard (0x0970)]
        Capabilities Received:
          [Dynamic Announcement (0x0506)]
          [Typed Wildcard (0x0970)]
ABC-CORE-1#show mpls ldp neigh 10.64.255.2 det
    Peer LDP Ident: 10.64.255.2:0; Local LDP Ident 10.64.255.1:0
        TCP connection: 10.64.255.2.36718 - 10.64.255.1.646
        Password: not required, none, in use
        State: Oper; Msgs sent/rcvd: 1193/1191; Downstream; Last TIB rev sent 130
        Up time: 16:25:05; UID: 8; Peer Id 0;
        LDP discovery sources:
          GigabitEthernet0/2; Src IP addr: 10.64.0.2
            holdtime: 15000 ms, hello interval: 5000 ms
        Addresses bound to peer LDP Ident:
          10.64.2.5       192.168.128.254 10.64.0.2       10.64.0.9
          10.64.255.2     10.64.254.2
        Peer holdtime: 180000 ms; KA interval: 60000 ms; Peer state: estab
        Clients: Dir Adj Client
        Capabilities Sent:
          [Dynamic Announcement (0x0506)]
          [Typed Wildcard (0x0970)]
        Capabilities Received:
          [Dynamic Announcement (0x0506)]
          [Typed Wildcard (0x0970)]
I've just enabled MPLS IGP sync this morning aftere reading a few articles however I'm not convicnced that's going to make much difference, has anyone ever experieced this before?
Thanks,
Duncan.

Duncan Mossop wrote:Hello,I'm having an intermittent issue with LDP sessions dropping between one specific router and it's two peers.Solution background:We have 3 x 7201 (NPE-G2) running c7200p-spservicesk9-mz.150-1.M5.bin.The routers are arranged in a "triangle" with a link to each router utilising G0/2 + 3 on each router, IGP is OSPF with all routers + loopbacks being in OSPF Area 0. OSPF RID + MPLS RID is Lo0.Routers are called ABC-CORE-1, CCC-CORE-1, CBC-CORE1.During the "outage" the DLP session between ABC->CBC remains constant without issue, however the LDP sessions with CCC-CORE1 both drop stating the following:ABC-CORE-1#show logApr 3 17:30:40.236: %LDP-5-NBRCHG: LDP Neighbor 10.64.255.2:0 (1) is DOWN (Received error notification from peer: Holddown time expired)Apr 3 17:30:44.180: %LDP-5-NBRCHG: LDP Neighbor 10.64.255.2:0 (1) is UPCCC-CORE-1#show log.Apr 3 17:30:39: %LDP-5-NBRCHG: LDP Neighbor 10.64.255.1:0 (1) is DOWN (Discovery Hello Hold Timer expired).Apr 3 17:30:43: %LDP-5-NBRCHG: LDP Neighbor 10.64.255.1:0 (3) is UPNeighbor output:CCC-CORE-1#sh mpls ldp neigh 10.64.255.1 det    Peer LDP Ident: 10.64.255.1:0; Local LDP Ident 10.64.255.2:0        TCP connection: 10.64.255.1.646 - 10.64.255.2.36718        Password: not required, none, in use        State: Oper; Msgs sent/rcvd: 1191/1192; Downstream; Last TIB rev sent 130        Up time: 16:24:42; UID: 10; Peer Id 2;        LDP discovery sources:          GigabitEthernet0/2; Src IP addr: 10.64.0.1            holdtime: 15000 ms, hello interval: 5000 ms        Addresses bound to peer LDP Ident:          10.64.2.1       192.168.128.126 10.64.0.1       10.64.0.5          10.64.255.1     10.64.254.1        Peer holdtime: 180000 ms; KA interval: 60000 ms; Peer state: estab        Clients: Dir Adj Client        Capabilities Sent:          [Dynamic Announcement (0x0506)]          [Typed Wildcard (0x0970)]        Capabilities Received:          [Dynamic Announcement (0x0506)]          [Typed Wildcard (0x0970)]ABC-CORE-1#show mpls ldp neigh 10.64.255.2 det    Peer LDP Ident: 10.64.255.2:0; Local LDP Ident 10.64.255.1:0        TCP connection: 10.64.255.2.36718 - 10.64.255.1.646        Password: not required, none, in use        State: Oper; Msgs sent/rcvd: 1193/1191; Downstream; Last TIB rev sent 130        Up time: 16:25:05; UID: 8; Peer Id 0;        LDP discovery sources:          GigabitEthernet0/2; Src IP addr: 10.64.0.2            holdtime: 15000 ms, hello interval: 5000 ms        Addresses bound to peer LDP Ident:          10.64.2.5       192.168.128.254 10.64.0.2       10.64.0.9          10.64.255.2     10.64.254.2        Peer holdtime: 180000 ms; KA interval: 60000 ms; Peer state: estab        Clients: Dir Adj Client        Capabilities Sent:          [Dynamic Announcement (0x0506)]          [Typed Wildcard (0x0970)]        Capabilities Received:          [Dynamic Announcement (0x0506)]          [Typed Wildcard (0x0970)]I've just enabled MPLS IGP sync this morning aftere reading a few articles however I'm not convicnced that's going to make much difference, has anyone ever experieced this before?Thanks,Duncan.
For anyone that's interested I fixed this problem after some in depth troubleshooting.
Turns out the CCC router has CEF disabled.
I followed the through the following process:
Noticed flushes in the inteface counters -> researched SPD (selective packet discard) -> looked into CPU usage -> noticed IP Input process running 90%+, checked CEF with "show ip cef" showed a full adjancency table.
Checked the command "show cef interface"
Boom, "CEF Switching disabled" on every interface.
"no ip cef" "ip cef" , fixed.
For reference the running config did indeed show "ip cef" as entered and turned on.
Only thing I can think is when we upgraded from 12.4 to 15.0(1)M there was a glitch with CEF....
Very strange.

OSPF opaque (MPLS-TE)

Similar Messages

Maybe you are looking for