04-12-2010 01:26 PM - edited 03-06-2019 10:34 AM
In support of a SAN setup, I would like to set a specific mtu size per vlan. I don't see a mtu parm under the interface vlan sub-commands. I am able to set the system mtu jumbo command which applies to all interfaces on the 3750E. Upon doing this I see the following:
Vlan88 is up, line protocol is down
Hardware is EtherSVI, address is 9caf.ca76.b4c1 (bia 90af.ca76.b4c1)
MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,
GigabitEthernet1/0/1 is down, line protocol is down (notconnect)
Hardware is Gigabit Ethernet, address is 9caf.ca76.b481 (bia 90af.ca76.b481)
MTU 9198 bytes, BW 10000 Kbit, DLY 1000 usec,
other info:
1#sh vlan mtu
VLAN SVI_MTU MinMTU(port) MaxMTU(port) MTU_Mismatch
---- ------------- ------------- ------------ ------------
1 1500 9198 9198 No
#sh system mtu
System MTU size is 1500 bytes
System Jumbo MTU size is 9198 bytes
Routing MTU size is 1500 bytes
My question is will the system mtu jumbo be inherited by the Vlan? or is their a way to set it by Vlan? (e.g. If the above port is part of the above vlan)
thanks
Solved! Go to Solution.
04-12-2010 01:39 PM
jawill47ec wrote:
In support of a SAN setup, I would like to set a specific mtu size per vlan. I don't see a mtu parm under the interface vlan sub-commands. I am able to set the system mtu jumbo command which applies to all interfaces on the 3750E. Upon doing this I see the following:
Vlan88 is up, line protocol is down
Hardware is EtherSVI, address is 9caf.ca76.b4c1 (bia 90af.ca76.b4c1)
MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,GigabitEthernet1/0/1 is down, line protocol is down (notconnect)
Hardware is Gigabit Ethernet, address is 9caf.ca76.b481 (bia 90af.ca76.b481)
MTU 9198 bytes, BW 10000 Kbit, DLY 1000 usec,other info:
1#sh vlan mtu
VLAN SVI_MTU MinMTU(port) MaxMTU(port) MTU_Mismatch
---- ------------- ------------- ------------ ------------
1 1500 9198 9198 No#sh system mtu
System MTU size is 1500 bytes
System Jumbo MTU size is 9198 bytes
Routing MTU size is 1500 bytesMy question is will the system mtu jumbo be inherited by the Vlan? or is their a way to set it by Vlan? (e.g. If the above port is part of the above vlan)
thanks
James
You can't set mtu on a per vlan basis on the 3750E only on a system wide basis. The vlan will not "inherit" the values as such. So when you set the mtu it applies globally to the switch.
Jon
04-12-2010 02:12 PM
Hi James,
From a 3750-E config
For Layer-3 is 9000
Switch-B(config)#system mtu routing ?
<1500-9000> MTU size in bytes
Switch-B(config)#system mtu routing
For Layer-2 is 9198
Switch-B(config)#system mtu jumbo ?
<1500-9198> Jumbo MTU size in bytes
Switch-B(config)#system mtu jumbo
HTH
Reza
04-12-2010 01:39 PM
jawill47ec wrote:
In support of a SAN setup, I would like to set a specific mtu size per vlan. I don't see a mtu parm under the interface vlan sub-commands. I am able to set the system mtu jumbo command which applies to all interfaces on the 3750E. Upon doing this I see the following:
Vlan88 is up, line protocol is down
Hardware is EtherSVI, address is 9caf.ca76.b4c1 (bia 90af.ca76.b4c1)
MTU 1500 bytes, BW 1000000 Kbit, DLY 10 usec,GigabitEthernet1/0/1 is down, line protocol is down (notconnect)
Hardware is Gigabit Ethernet, address is 9caf.ca76.b481 (bia 90af.ca76.b481)
MTU 9198 bytes, BW 10000 Kbit, DLY 1000 usec,other info:
1#sh vlan mtu
VLAN SVI_MTU MinMTU(port) MaxMTU(port) MTU_Mismatch
---- ------------- ------------- ------------ ------------
1 1500 9198 9198 No#sh system mtu
System MTU size is 1500 bytes
System Jumbo MTU size is 9198 bytes
Routing MTU size is 1500 bytesMy question is will the system mtu jumbo be inherited by the Vlan? or is their a way to set it by Vlan? (e.g. If the above port is part of the above vlan)
thanks
James
You can't set mtu on a per vlan basis on the 3750E only on a system wide basis. The vlan will not "inherit" the values as such. So when you set the mtu it applies globally to the switch.
Jon
04-12-2010 01:51 PM
Jon,
Thanks for the reply. A follow-up question. Is the global max mtu 9198? The reason I ask is in comparison to another vendor switch which this 3750E is replacing supported per interface mtu up to 9216.
thanks,
james
04-12-2010 02:12 PM
Hi James,
From a 3750-E config
For Layer-3 is 9000
Switch-B(config)#system mtu routing ?
<1500-9000> MTU size in bytes
Switch-B(config)#system mtu routing
For Layer-2 is 9198
Switch-B(config)#system mtu jumbo ?
<1500-9198> Jumbo MTU size in bytes
Switch-B(config)#system mtu jumbo
HTH
Reza
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