Hi,
While you come back with those questions, I thought this is a great question, and more so b'cos not often you are in this situation, hence the experience is never first hand.
I am not an expert on networking stuff, but I will try to attempt this.
My thoughts below based on the ingredients you have provided in your query.
Your case: [Please correct]
1) ifgrp = a0a
2) Vlan Port = a0a-13 <---Broadcast Domain MTU 1500
3) Physical Port = [e0c,e0d] <---MTU 9000
You want to change the MTU of:
2) Vlan Port = a0a-13 <---Broadcast Domain MTU 1500
Question:
Is the vlan port a0a-13 part of a separately defined (Dedicated) broadcast domain, if yes, then you use the following command, this will briefly disrupt the connections.
The following command changes the MTU to 9000 for all ports in the broadcast domain test:
cluster1::> network port broadcast-domain modify -broadcast-domain test -mtu 9000
Warning: Changing broadcast domain settings will cause a momentary data-serving
interruption.
Do you want to continue? {y|n}: y
If the vlan port a0a-13 is not dedicated and is part of the default broadcast domain which has a mtu value 1500, then changing the mtu will change the mtu on all the vlan-tagged and non-taggged ports which may not be what you need.
For example: Default broadcast domain [mtu-1500]
|--------->a0a-10 ---LIF
|
|--------->a0a-20 ---LIF
a0a[e0c-e0c]---|
|--------->a0a-30 ---LIF
|
|--------->a0a-40----LIF
However, if you want to change the above vlan a0a-10 mtu from 1500 to 9000 mtu, then you could split this off into new BD without disruptions.
::> broadcast-domain split -broadcast-domain Storage -new-broadcast-domain vlan10 -ports node-01:a0a-10,node-02:a0a-10
After the split command is run, a new broadcast-domain and failover-group will be created along with updating the failover-group on the appropriate LIFs. After this, you can use modify command to can change the mtu to 9000 for that vlan broadcast domain.
Experts, let us know, if this is correct.