1. Understanding Mesh Ethernet Bridging
What does it accomplish?
Allows bridging multiple wired ethernets together via Wireless Mesh backhaul links
Typical uses:
Bridging a remote building’s wired network to a primary site’s
Video cameras or surveillance devices (wired) connected directly to Maps’ ethernet ports
Key Terms:
Backhaul: Path toward the WLC. May be wired (in the case of a Rap) or wireless (in the case of a Map)
Rap: Root Access Point, wired connection with path to WLC (backhaul)
Map: Mesh Access Point, no wired connection with path to WLC (backhaul). May optionally have wired connection to end node (such as a video camera) or remote switch (‘remote’ with respect to the backhaul path to the WLC
Vlan Transparent: ‘Legacy’ method for ethernet bridging. VLAN tags are not handled and packets are bridged as untagged packets. This is typically not used. Is enabled by default for backward compatibility
Ethernet Vlan Tagging: Ethernet bridging with vlan tagging functionality. Useful for trunking multiple vlans to remote switches connected to Maps’ ethernet ports.
Native Vlan: Untagged vlan on a trunk. Vlan 1 by default on Cisco switches.

2. Mesh Ethernet Bridging Configuration Steps and Notes
1) Configure Rap’s and Maps, verify Mesh adjacencies
We won’t go into much detail as the focus of this document is Mesh Ethernet Bridging. Refer to these documents for basic mesh configuration reference:
Mesh Config Guide:
7.0 Mesh Deployment Guide:
2) Decide if Vlan Transparent or Vlan Tagging is more appropriate
If there is no need to pass multiple vlans over the mesh backhaul, keep it simple. Use Vlan Transparent. The only additional configuration needed is to confirm that Vlan Transparent is enabled (which it is by default), then enable Ethernet Bridging on all of the Rap’s and Map’s in the sector.
In most deployments there is a need to pass multiple vlans over the mesh backhaul, so Vlan Tagging should be chosen.

3. Mesh Ethernet Bridging Configuration Steps and Notes
3a) Vlan Transparent
Verify that Vlan Transparent is enabled:
Enable Ethernet Bridging on all relevant Rap’s and Map’s:
With simply the above configs, whatever untagged traffic is received on the Rap’s or Map’s ports will be bridged across the backhaul. For example, if both the Rap’s and Map’s switch ports are assigned to access mode vlan 1, all traffic will be bridged. Assuming that both switches have vlan 1 interfaces, you should be able to ping between the two.

4. Mesh Ethernet Bridging Configuration Steps and Notes
3b) Vlan Tagging
Disable Vlan Transparent
Enable Ethernet Bridging on all relevant Rap’s and Map’s:
It is commonly assumed that the Rap’s ethernet port should be configured as a trunk, along with the desired vlans.
If you read the config guide very closely, you’ll see that there is no need to configure the Rap’s port.
This is due to the fact that trunking subinterfaces are dynamically configured on the Rap’s ethernet backhaul on demand.
For example, a Rap has a child Map and both have Ethernet Bridging with Vlan Tagging enabled. You configure the Map’s ethernet interface to tag for vlan 2. It works. How? The Rap dynamically creates a .2 dot1q subinterface. This is referred to as ‘Vlan Registration’. This will be elaborated on and demonstrated in the next slides.
Another difficult to explain concept is that with Vlan Tagged Ethernet Bridging, the Rap’s switchport native vlan (untagged) will function as the mesh management network. Traffic from this network is not forwarded through the Maps’ ethernet ports. For example, the Rap’s switchport native vlan is 1. There’s a DHCP server on vlan 1. When the Raps and Maps associate, they should be able to obtain ip addresses via DHCP on vlan 1. If you were to connect a DHCP client to the map’s switch on vlan 1, it will not get an address from the DHCP server on the Rap’s wired network. This concept will also be demonstrated next.

5. Working Mesh Ethernet Bridging Configuration and Verification
Fas0 001d.a1cd.db98
Jk1242-1
RAP
802.11a
5Ghz radio
Fas0 001d.a1cd.daf0
MAP
Jk1242-2
interface FastEthernet0/8
switchport trunk encap dot1q
switchport trunk allowed vlan 1-3
switchport mode trunk
interface GigabitEthernet0/9
switchport trunk encap dot1q
switchport trunk native vlan 2
switchport trunk allowed vlan 2-3
switchport mode trunk
Client traffic can’t use RAP’s
Switchport native vlan
Fas0/8
Gig0/9
Vlan
Vlan
Vlan
jk #show interfaces trunk
Port Mode Encap Native vlan
Fa0/1 on q
Fa0/8 on q Jk Jk
Gig0/23
Vlan3
(DHCP Server)
Fas0/1
Gig0/24
interface FastEthernet0/1
switchport trunk encap dot1q
switchport trunk allowed vlan 1-3
switchport mode trunk
Vlan2
Port1
Mgmt
WLC-2106
Tested with
And

6. Working Mesh Ethernet Bridging Verification
RAP:
jk1242-1#show mesh adjacency child
show MESH Adjacency Child
ADJ 1 Identity 001d.a1cd.daf0 MA: 001e.1306.e27f ver 0x20 minver 0x0 on device Dot11Radio:1 txpkts txretries 1649
Flags: CHILD BEACON
jk1242-1#sho ip int brief
Interface IP-Address OK? Method Status Protocol
BVI YES DHCP up up
Dot11Radio unassigned NO unset up up
Dot11Radio unassigned NO unset up up
FastEthernet unassigned NO unset up up
FastEthernet unassigned YES unset up up
FastEthernet unassigned YES unset up up
Virtual-Dot11Radio unassigned YES unset up up
jk1242-1#show mesh ethernet vlan config running
Running Ethernet VLAN Configuration
Ethernet Interface: 0 mode: TRUNK Native Vlan: 1
Vlans:
MAP:
jk1242-2#show mesh adjacency parent
show MESH Adjacency Parent
ADJ 1 Identity 001d.a1cd.db98 MA: 001e.1306.e7bf ver 0x20 minver 0x20 on device Dot11Radio:1 txpkts txretries 817
Flags: UPDATED NEIGH PARENT BEACON
jk1242-2#show ip int brief
BVI YES DHCP up up
Dot11Radio unassigned NO unset administratively down down
jk1242-2#show mesh ethernet vlan config running
Ethernet Interface: 0 mode: TRUNK Native Vlan: 4
Vlans: 2 3

7. Mesh Ethernet Bridging RAP use of native vlan other than 1
Changes from previous config:
Change RAP’s trunk native vlan to 2
Reboot RAP & MAP to expedite AP DHCP change
Result
Functional with Map using same ethernet native vlan
As RAP, but corresponding vlan (vlan 2 in this
example is not forwarded or usable via the MAP’s
Ethernet interface
Mesh Ethernet Bridging
RAP use of native vlan other than 1
Fas0 001d.a1cd.db98
Jk1242-1
RAP
802.11a
5Ghz radio
Fas0 001d.a1cd.daf0
MAP
Jk1242-2
interface FastEthernet0/8
switchport trunk encap dot1q
switchport trunk native vlan 2
switchport trunk allowed vlan 1-3
switchport mode trunk
interface GigabitEthernet0/9
switchport trunk encap dot1q
switchport trunk native vlan 2
switchport trunk allowed vlan 2-3
switchport mode trunk
Client traffic can’t use RAP’s
Switchport native vlan
Fas0/8
Gig0/9
Vlan
Vlan
Vlan
jk #show interfaces trunk
Port Mode Encap Native vlan
Fa0/1 on q
Fa0/8 on q Jk Jk
Gig0/23
Vlan3
Fas0/1
Gig0/24
interface FastEthernet0/1
switchport trunk encap dot1q
switchport trunk allowed vlan 1-3
switchport mode trunk
Vlan2
Port1
No IP
Mgmt
WLC-2106
Tested with
And

8. Mesh Ethernet Bridging RAP use of native vlan other than 1 Verification
jk1242-1#show mesh adjacency child
show MESH Adjacency Child
ADJ 2 Identity 001d.a1cd.daf0 MA: 001e.1306.e27f version 0x20 minor version 0x20 txpkts txretries 620
Flags: UPDATED CHILD BEACON
jk1242-1#ping
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to , timeout is 2 seconds:
.!!!!
Success rate is 80 percent (4/5), round-trip min/avg/max = 1/1/2 ms
jk1242-1#sho ip int brief
Interface IP-Address OK? Method Status Protocol
BVI YES DHCP up up
Dot11Radio unassigned NO unset up up
Dot11Radio unassigned NO unset up up
FastEthernet unassigned NO unset up up
FastEthernet unassigned YES unset up up
FastEthernet unassigned YES unset up up
Virtual-Dot11Radio unassigned YES unset up up
jk1242-1#show mesh ethernet vlan config running
Running Ethernet VLAN Configuration
Ethernet Interface: 0 mode: TRUNK Native Vlan: 1
Vlans: 2 3
MAP:
jk1242-2#sho mesh adjacency parent
show MESH Adjacency Parent
ADJ 1 Identity 001d.a1cd.db98 MA: 001e.1306.e7bf version 0x20 minor version 0x20 txpkts txretries 963
Flags: UPDATED NEIGH PARENT BEACON
jk1242-2#ping
Sending 5, 100-byte ICMP Echos to , timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 1/1/2 ms
jk1242-2#sho ip int brief
BVI YES DHCP up up
Dot11Radio unassigned NO unset administratively down down
jk1242-2#show mesh ethernet vlan config running
Ethernet Interface: 0 mode: TRUNK Native Vlan: 2
Vlans: 3