Distributed trunking restrictions

There are several restrictions with distributed trunking:

  • Beginning with software version K.15.07, the switch will not allow both Distributed Trunking and MAC-based mirroring to function simultaneously. The switch will respond as follows:

    • If the user attempts to configure both, an error message will appear.

    • When a switch is updated from older software to K.15.07, if the older config file has both Distributed Trunking and MAC-based mirroring, the switch will automatically remove the MAC-based mirroring lines from the config file, and will give an explanatory error message.

  • If a switch is running K.15.07 and an existing config file that has both Distributed Trunking and MAC-based mirroring is loaded onto the switch, the switch will automatically remove the MAC-based mirroring lines from the config file, and will give an explanatory error message.

  • All DT linked switches must be running the same software version.

  • The port trunk links should be configured manually (using manual LACP or manual trunks.) Dynamic linking across switches is not supported.

  • A distributed trunk can span a maximum of two switches.

  • A maximum total of 144 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 144 manual trunks per switch includes distributed trunks as well.

  • ARP protection is not supported on the distributed trunks.

  • Dynamic IP Lockdown protection is not supported on the distributed trunks.

  • QinQ in mixed VLAN mode and distributed trunking are mutually exclusive.

  • Source Port Filter cannot be configured on an InterSwitch Connect (ISC) port.

  • Features not supported include:

    • SVLANs in mixed mode on DT or ISC links

    • Meshing

    • IPv6 routing