Switch Meshing
Switch Meshing Fundamentals
Backward
Compatibility Note
Switch 3
Switch 1
Switch 2
Switch Mesh
Domain
This topology forms a
broadcast loop unless
you configure STP or
RSTP on the network.
Figure 7-4. Example of an Unsupported Topology
• The switch blocks traffic on a meshed port connected to a non-
meshed port on another switch.
• Switch meshing does not allow trunked links (FEC, LACP, or Trunk)
between meshed ports.
Linking a non-mesh device or port into the mesh causes the meshed switch
port(s) connected to that device to shut down.
The HP ProCurve 3400cl, 6400cl, and 5300xl switches can interoperate with
older devices in a switch mesh only after being placed in backwards compat-
ibility mode. This is done with the mesh backward-compat command.
Using a Heterogeneous Switch Mesh
You can use 3400cl, 6400cl, and 5300xl switches together with any of the older
HP Procurve Switch 1600M/2400M/2424M/4000M/8000M models. These
restrictions also apply:
â– All 3400cl, 6400cl, and 5300xl switches in the mesh must be placed in
backward-compatible mode. This is done with the mesh backward-compat
command.
â– The older models cannot be used in a mesh environment with 3400cl,
6400cl, and 5300xl switches where there is a duplicate MAC address on
multiple switches and different VLANs. If you add an older model switch
in this environment after the mesh is established, this switch will not be
admitted to the mesh. If an older model switch is operating in a mesh with
3400cl, 6400cl, and/or 5300xl switches and you introduce a topology that
creates a duplicate MAC address on multiple switches, the device
accessed by these multiple switches will be blocked. For example:
7-8