Jumbo Frame errors on switch

[Consuro]

have a customer that is experiencing alerts on his Procurve 5406zl switch.  Alerts are for "undersized/giant packets on port.... (SAN)".    This started happening after we installed a Dell EqualLogic iSCSI SAN for DR replication.   He gets these alerts almost every 5 min.

I believe the issue is Jumbo Frames not being configured on his switch(es) but wondere if it might also be that we have to configure his ESXhost for Jumbo Frames.   If so, how is this done?  He is using 1GB adapters.

[Troy_Clavell]

see below

http://kb.vmware.com/kb/1007654

[Consuro]

thanks Troy

[Troy_Clavell]

make sure you run the command below first, if jumbo frames are enabled you should look similar to.

~ # esxcfg-vswitch -l
Switch Name      Num Ports   Used Ports  Configured Ports  MTU     Uplinks
vSwitch0         256         5           256               9000    vmnic2,vmnic0

[IRIX201110141]

Well, your problem have nothing todo with VMware/vSphere at first place. The EQLs have enable Jumbo Frames on default so this might be the reason why you see the errors now, after setup and activiating LUN replication.

Checking the vSwitch in one thing.. but you have also take a look to the VMKs (Portgroups) and the NICs.

[esx-node-01.example.com]:~ $ esxcfg-nics -l | grep 9000
vmnic11 0000:1a:00.01 igb         Up   1000Mbps  Full   00:1b:21:1f:db:3d 9000   Intel Corporation 82575GB Gigabit Network Connection
vmnic14 0000:1e:00.00 igb         Up   1000Mbps  Full   00:1b:21:1f:d6:bc 9000   Intel Corporation 82575GB Gigabit Network Connection
vmnic15 0000:1e:00.01 igb         Up   1000Mbps  Full   00:1b:21:1f:d6:bd 9000   Intel Corporation 82575GB Gigabit Network Connection
vmnic18 0000:24:00.00 igb         Up   1000Mbps  Full   00:1b:21:1f:d9:2c 9000   Intel Corporation 82575GB Gigabit Network Connection
vmnic19 0000:24:00.01 igb         Up   1000Mbps  Full   00:1b:21:1f:d9:2d 9000   Intel Corporation 82575GB Gigabit Network Connection
vmnic7  0000:16:00.01 igb         Up   1000Mbps  Full   00:1b:21:1f:d9:8d 9000   Intel Corporation 82575GB Gigabit Network Connection

[esx-node-01.example.com]:~ $ esxcfg-vmknic -l
Interface  Port Group/DVPort   IP Family IP Address                              Netmask         Broadcast       MAC Address       MTU     TSO MSS   Enabled Type
vmk0       iSCSI-1             IPv4      192.168.x.1                             255.255.255.0   192.168.5.255   00:50:56:7f:00:27 9000    65535     true    STATIC
vmk1       iSCSI-2             IPv4      192.168.x.11                            255.255.255.0   192.168.5.255   00:50:56:78:b4:9d 9000    65535     true    STATIC
vmk2       iSCSI-3             IPv4      192.168.x.21                            255.255.255.0   192.168.5.255   00:50:56:75:77:2e 9000    65535     true    STATIC
vmk3       iSCSI-4             IPv4      192.168.x.31                            255.255.255.0   192.168.5.255   00:50:56:76:fd:74 9000    65535     true    STATIC
vmk6       vMotion             IPv4      192.168.x.1                             255.255.255.0   192.168.6.255   00:50:56:74:54:af 1500    65535     true    STATIC
vmk7       NFS                 IPv4      192.168.x.31                            255.255.255.0   192.168.4.255   00:50:56:7b:c3:1b 1500    65535     true    STATIC
vmk4       iSCSI-5             IPv4      192.168.x.1                             255.255.255.0   192.168.7.255   00:50:56:7c:58:61 9000    65535     true    STATIC

If youre running esxcli swiscsi nic list -d vmhbaXX you'll get an overview about the binding to the swISCSI if you use it (and iam sure youre using it).

Befor you touch the ESX be sure that you have enable the Jumbo Frames on your pSwitch first!

Regards

Joerg

[Consuro]

thanks very much.  very helpful