Troubleshooting for MPLS-related experiments

One: MPLS in PE

1.LDP Neighbors cannot establish

A, see if the neighbor does not have any neighbors then first look at the configuration

is the protocol correct ?

whether the related interface is enabled MPLSIP

B, the bottom of the Route-id not reach

C,646 was cut off

LDP 's Hello packet UDP 646

Update Packet TCP 646

The TDP is 711 .

D , Copp kill it. 646

2. Track the destination route PE address

in the Check show MPLS forwarding-table on PE

Tracking LDP tab one-to-one query

find out where the problem lies No Label

Show Run | S MPLS

A,no MPLS ldp Advertise-label

correct Method

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B. See if CEF is enabled

C, see if there is a label broken chain

routing entries for MPLS cannot be changed when a change occurs , the label breaks

If there is an intermediate device See if both labels exist

second, solve the routing

1. View neighbor relationships between PE

(including VPNV4 's neighbor relationship show ip bgp vpnv4 all sum)

See the neighbor relationship between PE and route reflector if no neighbor is built between PE

A , Solving common BGP neighbor problems

B , VPN must be activated in the cluster

2 , there is a neighbor after check is PE no corresponding route show ip Route VRF * * *   

(1), severed-side routing not entered

A , check the neighbor relationship between PE and CE (BGP view VPN neighbor)

Whether the interface is zoned into the VRF

Check Configuration to resolve neighbor problems

if BGP Neighbor Remember in familyvrf under Configuration

If Eigrp looks at the neighbor

Autonomous-system use as number consistent with CE end

(2), if the peer-to-peer route is not entered

First of all, to ensure that the end of the first learning their own route

1. Check BGP delivery

Whether the peer is re-published in BGP

route-map named import map under VRF

Check the configuration of the route reflector : reflect the appropriate configuration Carry Properties

Check if the synchronicity-side VRF Transceiver label corresponds

3, check whether each CE receives a relative route (note which interface the routing entry is)

directly see if it is correct in the the IGP is re-sent on PE

two: Data plane

1, on the PE test

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See route entry contains two layers label

The outer label is the The inner label of the MPLS neighbor encapsulated (P router R1,R2) is encapsulated by the VRF interface of the PE

Accessibility tools

no matter TDP or LDP view command: view command when MPBGP

R2#show MPLS ldp neighbor View neighbor Relationships

R2#show MPLS LDP bindings view LIB table

R2#show MPLS forwarding-table view LFIB table

when running MPLS ,the tag number will be carried in the FIB

R2#show IP cef Detail r1#show IP cef vrf vpnadetail view FIB table

define upstream and downstream routers based on the direction of the data plane, on the run Unicast routing protocol on the basis of the cef generates fib table, and then TDP/LDP will be based on the fib lib table;

Finally, all routers will FIB and the LIB Combine Generation LFIB The traffic that is forwarded to the data tree will carry the label that is distributed locally for that segment, and the label number is changed to the downstream router when the direction is reached;

Local Routes routes to and from neighbors consistent otherwise will appear label Broken Chain

Example: Local loopback interface /24 Distal /32

and Summary routing

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Troubleshooting for MPLS-related experiments