Problem Details: I have two switches: Nexus 3064 (ver 5.0(3)U1(2)) and Cisco 6509.
The 6509:
1 x WS-x6708-10GE 8 port Ten Gig module version 3.5, firmware 12.2(18r)S1.
2 x sup 720's, with PFC3A.
2 x WS-x6348-rj-45
4 x WS-x6748-ge-tx
The IOS is ipservicesk9-mz 12.2(33)SXH8b.
Both switches have been running fine for quite a while(not connected to each other). I
then ran a fiber connection between port Nexus:1/48 and 6509:Te9/1
The Nexus is configured for jumbo frames:
policy-map type network-qos jumbo
class type network-qos class-default
mtu 9000
system qos
service-policy type network-qos jumbo
interface Vlan323
no shutdown
mtu 9000
ip address 172.19.4.253/24
ip pim sparse-mode
(all 48 ports are configured the same)
interface Ethernet 1/48
switchport access vlan 323
mtu 9000
The above works on the Nexus switch, I have no problems with jumbo frames inbetween Nexus
users.
On the 6509:
system jumbomtu 9000
interface Vlan 323
ip address 172.19.4.254 255.255.255.0
ip pim sparse-mode
mtu 9000
interface TenGigabit9/1
switchport
switchport mode access
switchport access vlan 323
mtu 9000
When I ping (of any packet size) from the Nexus to the 6509 @172.19.4.254, the 6509's CPU
goes to 100%. On occasion, we will get 1 out of 20 packets back in the reply.
I reduced the MTU size on the three 6509 parameters until the CPU stopped going 100%.
The magic number is 4175 bytes. 4176 and higher == 100% CPU.
I am willing to put the fiber link to 1500, but how does one change that for just one port
on the Nexus? I tried and it refuses to set the mtu. I also tried to setup a new
service-policy but that didn't seem to work either.
The Nexus users are all jumbo frame users. The users on the 6509 are all 1500 byte frame
users, except for one user on a 1 gig port (ws-6748-ge-tx) line card. It is this user whom
would like jumbos.
I'm more worried about why the 6509's CPU went to 100%!
Any idea?
thanks!
Mark
p.s. I attempted to put in a TAC request, but apparently my devices are not covered under SmartNet
