Interfaces | 133Port channels can contain a mix of 100, 1000, or 10000 Mbps Ethernet interfaces and TenGigabit Ethernetinterfaces. The interface speed (100, 1000, or 10000 Mbps) used by the port channel is determined by thefirst port channel member that is physically up. FTOS disables the interfaces that do not match theinterface speed set by the first channel member. That first interface may be the first interface that isphysically brought up or was physically operating when interfaces were added to the port channel. Forexample, if the first operational interface in the port channel is a TenGigabit Ethernet interface, allinterfaces at 1000 Mbps are kept up, and all 100/1000/10000 interfaces that are not set to 1000 Mbps speedor auto negotiate are disabled.1GbE and 10GbE Interfaces in Port ChannelsWhen both Gigabit and TenGigabitEthernet interfaces are added to a port channel, the interfaces mustshare a common speed. When interfaces have a configured speed different from the port channel speed, thesoftware disables those interfaces.The common speed is determined when the port channel is first enabled. At that time, the software checksthe first interface listed in the port channel configuration. If that interface is enabled, its speedconfiguration becomes the common speed of the port channel. If the other interfaces configured in that portchannel are configured with a different speed, FTOS disables them.For example, if four interfaces (TenGig 0/0, 0/1, 0/2, 0/3) in which TenGig 0/0 and TenGig 0/3 are set tospeed 100 Mb/s and the others are set to 1000 Mb/s, with all interfaces enabled, and you add them to a portchannel by entering channel-member tengigabitethernet 0/0-3 while in port channel interface mode, and FTOSdetermines if the first interface specified (TenGig 0/0) is up. After it is up, the common speed of the portchannel is 100 Mb/s. FTOS disables those interfaces configured with speed 1000 Mb/s or whose speed is1000 Mb/s as a result of auto-negotiation.In this example, you can change the common speed of the port channel by changing its configuration so thefirst enabled interface referenced in the configuration is a 1000 Mb/s speed interface. You can also changethe common speed of the port channel by setting the speed of the TenGig 0/0 interface to 1000 Mb/s.Uplink Port Channel: VLAN MembershipThe tagged VLAN membership of the uplink LAG is automatically configured based on the VLANconfiguration of all server-facing ports (ports 1 to 32).The untagged VLAN used for the uplink LAG is always the default VLAN 1.Server-Facing Port Channel: VLAN MembershipThe tagged VLAN membership of a server-facing LAG is automatically configured based on theserver-facing ports that are members of the LAG.The untagged VLAN of a server-facing LAG is auto-configured based on the untagged VLAN to whichthe lowest numbered server-facing port in the LAG belongs.
