The dynamic addition and removal of VLANs in SEAs with load sharing is supported by IBM. This means that in principle VLANs can be added or removed at any time. However, it is possible that there may be a brief delay in the forwarding of Ethernet frames.

IBM recommends resetting both SEAs to failover, before adding or removing VLANs (ha_mode=auto):

$ vios chdev ms05-vio1 ent46 ha_mode=auto
$ vios chdev ms05-vio2 ent44 ha_mode=auto
$

Then VLANs can be added or removed, starting with the primary SEA (here the VLAN 16 is added to the trunking adapter ent42 on virtual I/O server ms05-vio1):

$ lpar addvlan ms05-vio1 72 16
$

The VLAN is available immediately.

The same VLANs are then added or removed for the backup SEA (the trunking adapter is ent40 on virtual I/O server ms05-vio2):

$ lpar addvlan ms05-vio2 72 16
$

After all changes have been made to both SEAs, the VLANs of both SEAs should be checked again (“vios lssea -V“):

$ vios lssea -V ms05-vio1 ent46
SEA    LNAGG  NAME   TYPE     VSWITCH   MODE  ACTIVE  PRIORITY  PVID  VLAN_TAG_IDS
ent46  -      ent3   real     -         -     -       -         -     -
ent46  -      ent45  virtual  ETHTEST3  VEB   True    1         5     23
ent46  -      ent44  virtual  ETHTEST3  VEB   True    1         4     20,21,22
ent46  -      ent43  virtual  ETHTEST3  VEB   True    1         3     17,18,19
ent46  -      ent42  virtual  ETHTEST3  VEB   True    1         2     14,15,16
ent46  -      ent41  virtual  ETHTEST3  VEB   True    1         1     11,12,13
ent46  -      ent39  control  ETHCTRL   -     -       -         1     None
$
$ vios lssea -V ms05-vio2 ent44
SEA    LNAGG  NAME   TYPE     VSWITCH   MODE  ACTIVE  PRIORITY  PVID  VLAN_TAG_IDS
ent44  -      ent5   real     -         -     -       -         -     -
ent44  -      ent43  virtual  ETHTEST3  VEB   False   2         5     23
ent44  -      ent42  virtual  ETHTEST3  VEB   False   2         4     20,21,22
ent44  -      ent41  virtual  ETHTEST3  VEB   False   2         3     17,18,19
ent44  -      ent40  virtual  ETHTEST3  VEB   False   2         2     14,15,16
ent44  -      ent39  virtual  ETHTEST3  VEB   False   2         1     11,12,13
ent44  -      ent38  control  ETHCTRL   -     -       -         1     None
$

The added VLAN 16 is displayed correctly for both SEAs.

Finally, the SEAs are configured for load sharing again by setting the ha_mode attribute back to sharing:

$ vios chdev ms05-vio1 ent46 ha_mode=sharing
$ vios chdev ms05-vio2 ent44 ha_mode=sharing
$

A check of the distribution of the VLANs shows that both SEAs are active again (for their VLANs):

$ vios lssea -V ms05-vio1 ent46
SEA    LNAGG  NAME   TYPE     VSWITCH   MODE  ACTIVE  PRIORITY  PVID  VLAN_TAG_IDS
ent46  -      ent3   real     -         -     -       -         -     -
ent46  -      ent45  virtual  ETHTEST3  VEB   False   1         5     23
ent46  -      ent44  virtual  ETHTEST3  VEB   False   1         4     20,21,22
ent46  -      ent43  virtual  ETHTEST3  VEB   True    1         3     17,18,19
ent46  -      ent42  virtual  ETHTEST3  VEB   True    1         2     14,15,16
ent46  -      ent41  virtual  ETHTEST3  VEB   True    1         1     11,12,13
ent46  -      ent39  control  ETHCTRL   -     -       -         1     None
$