Port Trunking
Distributed Trunking
Distributed Trunking Restrictions
There are several restrictions with distributed trunking.
■ The port trunk links should be configured manually (manual LACP).
Dynamic linking across switches is not supported.
■ Only servers are supported as Distributed Trunking Devices (DTDs).
■ A distributed trunk can span a maximum of two switches.
■ A maximum total of 60 servers can be connected to two DT switches. Each
server can have up to four physical links aggregated in a single switch,
meaning that there can be a maximum of eight ports (four aggregated links
for each DT switch) included in a DT trunk.
■ Only one ISC link is supported per switch with a maximum of 60 DT trunks
supported on the switch. The ISC link can be configured as a manual LACP
trunk, non-protocol trunk, or as an individual link. Dynamic LACP trunks
are not supported as ISCs.
■ An ISC port becomes a member of all VLANs that are configured on the
switch. When a new VLAN is configured, the ISC ports become members
of that VLAN.
■ Port trunk links can be done only on a maximum of two switches that are
connected to a specific server.
■ Any VLAN that is in a distributed trunk must be configured on both
switches. By default, the distributed trunk belongs to the default VLAN.
■ There can be eight links in a distributed trunk grouped across two
switches, with a limit of four links per distributed trunking switch.
■ The limit of 60 manual trunks per switch includes distributed trunking
manual trunks as well.
■ IP routing and distributed trunking are mutually exclusive. Routing
restrictions with distributed trunking are switch-wide and do not apply to
the DT ports only.
■ Meshing and DT switches are mutually exclusive.
■ ARP protection is not supported on the distributed trunks.
■ STP is disabled on DT ports.
■ QinQ in mixed VLAN mode and distributed trunking are mutually exclu-
sive.
■ SVLANs in mixed mode are not supported on DT or ISC links.
■ DHCP snooping and IGMP snooping are not supported on DT links.
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