The server team has asked me to implement jumbo frames on a single VLAN, the one they use for vmotion. We have two pairs of 5548s, each pair running VPC for most connections. I would like to hear from anyone who has implemented this.
I am aware of many postings that describe how to enable jumbo frames globally, like this:
policy-map type network-qos jumbo
class type network-qos class-default
mtu 9216
exit
exit
system qos
service-policy type network-qos jumbo
exit
I am not clear how I can extend this principle to one VLAN only. Can anyone guide me?
Also, I am aware of a posting (https://supportforums.cisco.com/message/3869428#3869428) that shows some pitfalls of implementing jumbo frames in a VPC configuration. Pretty well all my connections are VPC, including all the FEXes, which are all dual-homed. In many cases, the VPC extends through to the servers so that the servers run port.channels across two FEXes. I am unclear whether the pitfalls are still valid, or whether I have to wait until my next maintenance slot (6 months away) to implement jumbo frames. Can jumbo frames be implement safely on the fly? How does enabling jumbo frames fit in with "conf sync" mode?
Could someone share their experience please?
Kevin Dorrell
Luxembourg
