Revert "README: remove inexact paragraph about stacking bonding/vlans/bridges"

This reverts commit ba09084d47643b630f3705242c1e6761d0412c46.

In fact, we still have limitations on how stacking is done. Bonds are
expected to be done on physical devices. Bonds on bonds are not
supported. In fact, there are some setups that cannot work
correctly. For example, let's assume the following:

 - eth0
 - eth1
 - vlan40@eth0
 - vlan41@eth1
 - vlan42@eth0
 - vlan43@eth1
 - bond0@(vlan40 + vlan41)
 - bond1@(vlan43 + vlan42)

On paper, we can still retrieve the real MAC addresses of various
stuff. However, Linux will alter the MAC addresses of the
VLAN. Moreover, depending on how bond1 is built, it can have the same
MAC address than bond0 or a different one. If MAC addresses are
propagated to the root, there may or may not have conflicts.

Putting bonds on physical interfaces should be the only sane thing to
do. While we could accomodate more complex setup, let's not try to do
something quite complex that nobody will use.

Hence the revert.

diff --git a/README.md b/README.md
index cfc873aba02e45c2e196351bce2464816f641ffa..8a7ce34c599dae83370d6c3eaa996fc8b02821af 100644 (file)
--- a/README.md
+++ b/README.md
@@ -20,6 +20,11 @@ SNMP subagent for net-snmp to get local and remote LLDP
 information. The LLDP MIB is partially implemented but the most useful
 tables are here. lldpd also partially implements LLDP-MED.
 
+lldpd supports bridge, vlan and bonding. bonding need to be done on
+real physical devices, not on bridges, vlans, etc. However, vlans can
+be mapped on the bonding device. You can bridge vlan but not add vlans
+on bridges. More complex setups may give false results.
+
 The following OS are supported:
 
  * FreeBSD