Etherchannel and root bridge Sim

[ionemoney]

The answer has the interfaces grouped into po11, and configured as trunk interfaces

no interface po11
interface range e0/0 - 2
switchport trunk encapsulation dot1q
switchport mode trunk
channel-group 11 mode active

However, don't we have to specifically configure int po11 as a trunk as well?

EX
Interface po11
switchport trunk encapsulation dot1q
switchport mode trunk
Switchport trunk allowed vlans x,x,x

?????

[help_desk]

On modern devices, when you configure the command "channel-group <number> mode <active|passive>" on interfaces, the configurations under the interfaces are copied to the Port-channel automatically.

[ionemoney]

On modern devices, when you configure the command "channel-group <number> mode <active|passive>" on interfaces, the configurations under the interfaces are copied to the Port-channel automatically.

Thank you!

[muddytechz]

My question would be for Task #2.  To ensure that Sw10 is always the root bridge.  Wouldn't you use priority of 0?  If you just use root primary then if another siwtch is added with a lower priority then it would take over.  Setting root primary only calculates for existing switches in topology.  

I should be able to find information to back this up if needed.

[help_desk]

You are correct that if another switch with a lower priority were added, it could take over as the root. But the task is for the current network, not what might happen later on.

The same logic applies even if we set SW10 to priority 0. If another switch with priority 0 shows up, the MAC address still decides the root, so that’s not an absolute guarantee either.

In real networks, the root primary command is the recommended and cleaner way to set the root bridge. It follows Cisco best practices, works with the existing topology, and meets the requirement without being overly aggressive.

[muddytechz]

You are correct that if another switch with a lower priority were added, it could take over as the root. But the task is for the current network, not what might happen later on.

The same logic applies even if we set SW10 to priority 0. If another switch with priority 0 shows up, the MAC address still decides the root, so that’s not an absolute guarantee either.

In real networks, the root primary command is the recommended and cleaner way to set the root bridge. It follows Cisco best practices, works with the existing topology, and meets the requirement without being overly aggressive

Explanation sounds good.  I just hate how they word their questions.  Makes it sound like both could be correct but unsure which is correct

---

You are correct that if another switch with a lower priority were added, it could take over as the root. But the task is for the current network, not what might happen later on.

The same logic applies even if we set SW10 to priority 0. If another switch with priority 0 shows up, the MAC address still decides the root, so that’s not an absolute guarantee either.

In real networks, the root primary command is the recommended and cleaner way to set the root bridge. It follows Cisco best practices, works with the existing topology, and meets the requirement without being overly aggressive

Explanation sounds good.  I just hate how they word their questions.  Makes it sound like both could be correct but unsure which is correct

I'm also not getting the expected results on task 1.  

First step to remove po 11.  It doesn't exist from beginning.

Even if I don't make any changes shouldn't trunks show up going to SW30.  I get nothing but SW30 does show up in show cdp.

I've tried reimporting the lab twice but something doesn't seem right.

[muddytechz]

Starting from the beginning.  Fix PortChannel 1.

conf t
int po 1
switchport trunk encap dot1q
switchport mode trunk

verify by show int trunk

po1 will now show up in trunks .

Now on to actual step to create PO/trunk with SW20.

I created po 11
conf t
int po 11
switchport trunk encap dot1q
switchprot mode trunk

then config interfaces

conf t
int range e 0/0 - 2
switchport trunk encap dot1q
switchport mode trunk
channel-group 11 mode active

All seemed to be working fine after that.  Please let me know if this doesn't look correct for some reason.

[help_desk]

You don't need to configure port channel 11 explicitly, as it will automatically be created when you add the interfaces to it via the command "channel-group 11 mode active".