Tim H.
ePlus Technology

Mike’s statement about setting a jumbo per system is not exactly how it works. The Nexus 5000 allows you to set an MTU per class. This is to allow for Ethernet and FCoE frames on the same medium. One could make policy map that specifies multiple MTU’s for the different classes and then apply to only some ports. System QoS applies to the entire system, or all ports unless otherwise configured.

Raj’s comment about the interface MTU – it is confusing since we are using class-based MTU configuration so technically the interface MTU is meaningless, you can safely ignore it. Please use “show policy-map interface” to determine the MTU per class of a given interface.

We have a defect to enhance the “show interface” output to convey the classful configuration:

CSCsl21529 Enhance CLI to display per class MTU

Regards,
John Gill
cisco
Nexus 5000 Customer Operations

show running-config shows following:

cisco5010# show running-config
version 4.1(3)N1(1)
feature telnet
no feature ssh
feature fex

username admin password 5 $1$xUKbUH4X$whNeBWSCkhx0gSgwzQfXY/ role network-
no password strength-check
ip host cisco5010 172.22.219.239
switchname cisco5010
logging event link-status default
service unsupported-transceiver
policy-map type network-qos jumbo
class type network-qos class-default
mtu 9216
system qos
service-policy type network-qos jumbo
snmp-server user admin network-admin auth md5 0xb95e70ca9942394accaa26fae49
priv 0xb95e70ca9942394accaa26fae49d8da8 localizedkey

vrf context management
ip route 0.0.0.0/0 172.22.219.1
vlan 1

did we miss anything? we appreciate your answer.

Thanks,
Raj

You’ll need to enable jumbo frames end-to-end. If you can’t/don’t want to enable jumbo frames on the 3750E and that’s where either the hosts or the storage connects, then you won’t be able to use jumbo frames. You’ll have a loss of connectivity.

I have a question for Nexus 5000 + NetAPP + Vmware ESX + 3750E solution.

I knew N5K is only support per system jumbo fram. If Netapp storage/Vmware ESX server/N5K enable jumbo frame(9000) and N5K connect to 3750E without jumbo frame by trunking interface, what is going to happend? packet drop?

Because I don’t want to enable jumbo frame on my existing 3750E with L3 routing feature.

is any good idea for that?

Thanks

Mike