mode bouncing...

i've been switching between negotiation modes in channel groups...
some things...

setting the channel group mode to on results in default etherchannel; no negotiation, similar to trunk mode on...
switching around protocols doesn't have to be performed with channel-priority, it can be done simply by choosing the channel group mode:


sw2950_01(config-if-range)#channel-group 6 mode ?
  active     Enable LACP unconditionally
  auto       Enable PAgP only if a PAgP device is detected
  desirable  Enable PAgP unconditionally
  on         Enable Etherchannel only
  passive    Enable LACP only if a LACP device is detected

when the interfaces go into errdisable, shut and no shut needs to be performed on the poX to bring the aggregated port back...

sw2950_01#sh etherch summ

Flags:  D - down        P - in port-channel

        I - stand-alone s - suspended

        H - Hot-standby (LACP only)

        R - Layer3      S - Layer2

        u - unsuitable for bundling

        U - in use      f - failed to allocate aggregator

        d - default port

Number of channel-groups in use: 2

Number of aggregators:           2

Group  Port-channel  Protocol    Ports

------+-------------+-----------+-----------------------------------------------

1      Po1(SU)         LACP      Fa0/5(Pd)   Fa0/6(P)

2      Po2(SU)         LACP      Fa0/7(Pd)   Fa0/8(P)

junk in the trunk...

sw2950_02(config)#int fa0/2
sw2950_02(config-if)#switchport nonegotiate
first, DTP (dynamic trunking protocol) is cisco proprietary and will not work with gray market switches...  use nonegotiate in a mixed environment... this disables DTP, will only become a trunk with ON or NONEGOTIATE ports, and  port ranges are not allowed with this command

sw2950_02(config)#int fa0/2
sw2950_02(config-if)#sw mode trunk
trunking is on... DTP signals are sent to the other connected port to initiate trunking if it is ON, AUTO, or DESIRABLE

if:
sw2950_02(config-if)#sw mode dynamic desirable
the port will become a trunk after detecting DTP signals of  ON, AUTO or DESIRABLE from the connected port

if:
sw2950_02(config-if)#sw mod dyn auto
the port will become a trunk if the other port is ON or DESIRABLE

if:
sw2950_02(config-if)#no sw mod trunk
trunking and DTP are disabled and this is the desired state for access ports; no dynamic establishments can occur

today's post was brought to you by Michael the network cat...

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