DLEP is a radio aware routing (RAR) protocol, which addresses the challenges faced when merging IP routing and radio frequency (RF) communications. Radio Aware Routing (RAR) is a mechanism where radios can interact with routing protocols (such as EIGRP) to signal the appearance, disappearance, and link conditions of one-hop routing neighbors.

The DLEP protocol runs between a router and its attached modems, allowing the modems to communicate link characteristics as they change, and convergence events (acquisition and loss of potential routing next-hops). DLEP provides an event driven mechanism instead of a timer-driven one and enables routing protocols to be radio-aware.

There are two methods for the router to locate its local WGB and set up DLEP sessions: auto discovery and manual configuration.

• In auto discovery mode, the router initiates the discovery process by sending a peer discovery signal to a well-known UDP multicast IPv4 address 224.0.0.117. Potential WGBs that receive the discovery signal will reply with peer offer and this signal contains the address/port combination. The router will then establish the TCP connection with WGB using that address and port information.

• In manual configuration method, router will use preconfigured address/port information to initialize the TCP connection directly.

Upon establishment of a TCP connection, the DLEP session will be setup.

The DLEP feature is supported for the following software releases, platforms, and AP Modes:

• Cisco 5900 Embedded Services Routers, Cisco IOS Release 15.7(3)M2 or greater

• WGB – Cisco IW3702 access point running autonomous image of Release 15.3(3)JI

• Wireless LAN Controller (WLC) – Release 8.8

The following figure shows a typical topology of DLEP deployment.

In this example, two WGBs are deployed in a vehicle as DLEP clients to provide redundant radio links. Two DLEP sessions are setup between each WGB and the DLEP server, which in this case, is Cisco Embedded Services Router (ESR). Each mesh AP (MAP) is configured with two SSIDs (SSID_A and SSID_B). Each WGB associates to a different SSID and establish a DLEP session with the ESR respectively. WGBs report radio link metrics to ESR through DLEP messages. ESR uses these metrics to cooperate with routing protocol like EIGRP to make better link selection.

Configure EIGRP on the remote ESR with static neighbor interface.

hostname ESR-Infra
interface Ethernet0/1
 ip address 100.100.1.2 255.255.255.0

interface Ethernet0/2
 ip address 100.100.2.2 255.255.255.0

router eigrp 100
 network 1.1.1.1 0.0.0.0
 network 100.100.1.0 0.0.0.255
 network 100.100.2.0 0.0.0.255
 neighbor 100.100.1.1 Ethernet0/1
 neighbor 100.100.2.1 Ethernet0/2
 eigrp router-id 1.1.1.1

Note	Contact your Cisco Support engineer for any troubleshooting support you may need.

• The following command triggers the WGB to send peer terminate to the DLEP server to remove the specified peer:

  wgb#clear dlep peer 

• The following command clears the DLEP client counters:

  wgb#clear dlep counters 

• The following command displays the DLEP client process event information:

  WGB#debug dlep client  [detail ]

• The following command displays the DLEP neighbor transaction information:

  
  WGB#debug dlep neighbor  {<mac-address >|all |detail |error |metric |state }
  
    H.H.H    DLEP client neighbor MAC addr
    all      debugging information for all DLEP neighbors
    detail   DLEP neighbor detail information
    error    DLEP neighbor error information
    metrics  DLEP neighbor metrics information
    state    DLEP neighbor state machine information
  

• The following commands display the DLEP peer transaction information:

  
  WGB#debug dlep peer  {detail |error |state |packet  {detail |dump |incoming |outgoing }}
    detail  DLEP peer detail information
    error   DLEP peer error information
    packet  display DLEP peer packet information
    state   DLEP peer state machine information
  
  WGB#debug dlep peer packet  {detail |dump |incoming |outgoing }
    detail    display DLEP client packet details
    dump      display DLEP peer packet as a hex dump
    incoming  filter DLEP client incoming packets
    outgoing  filter DLEP client outgoing packets
  

• The following commands display the DLEP timer detail information:

  WGB#debug dlep timer  [detail ]