Switching

Hi,

I'd like to increase max MTU on an irb interface, but it seems that my EX4300 wont let me. I can set it to values below 1500. If i set it to values above 1500 it commits fine, but the result is always 1500 max.

root@vc-sw1# run show interfaces irb.701 | match "Protocol inet"    
    Protocol inet, MTU: 1500
    Protocol inet6, MTU: 1500

{master:0}[edit]
root@vc-sw1# set interfaces irb unit 701 family inet mtu 1400 

{master:0}[edit]
root@vc-sw1# commit 
fpc0: 
configuration check succeeds
fpc1: 
commit complete
fpc0: 
commit complete

{master:0}[edit]
root@vc-sw1# run show interfaces irb.701 | match "Protocol inet"    
    Protocol inet, MTU: 1400
    Protocol inet6, MTU: 1500

{master:0}[edit]
root@vc-sw1# set interfaces irb unit 701 family inet mtu 1600       

{master:0}[edit]
root@vc-sw1# commit 
fpc0: 
configuration check succeeds
fpc1: 
commit complete
fpc0: 
commit complete

{master:0}[edit]
root@vc-sw1# run show interfaces irb.701 | match "Protocol inet"    
    Protocol inet, MTU: 1500
    Protocol inet6, MTU: 1500

{master:0}[edit]
root@vc-sw1# 

Please help...

Hello,

Try setting it like this:

set interface irb mtu <mtu above 1500>

commit

Regards,

Rushi

Already tried that, does not help...

Try to configure the higher MTU on all the physical interfaces that are part of vlan for whose IRB are you trying to increase the MTU.


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If this worked for you please flag my post as an "Accepted Solution" so others can benefit. A kudo would be cool if you think I earned it.

That does not work either. I can configure an interface with family inet and raise mtu from there, but an interface with family ethernet-switching in conjunction with an irb interface does not allow a higher mtu.

Time to upgrade switch i guess..

Edit: i did not increase MTU on trunk interface

Found the sollution: If you wish to increase the MTU of an irb interface, you should increase the MTU on all interfaces that have that vlan member configured. Lowest MTU of any interface is MTU of irb interface.

We have seen the same problem and resolution is one of our labs.

Ron