Port Trunking

Distributed Trunking

Distributed Trunking RestrictionsThere 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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