I have this problem with slow performance one way copying files from one server to another.
Iperf also shows this performance.
Server1 is connected to a 3560 giga-port in vlan 670, and there is a 1 gig trunk to a 6509.
The 6509 is configured with vrf and fwsm, and this is connected to another 6509 with at 10 gig trunk.
In this last 6509 the other server is connected in vlan 650.
Vlan 650 and 670 belongs to different vrf's, and needs to go thru the fwsm.
One way shows nice perfomance (iperf shows 800-900Mbit/s), but the other way is about half the performance.
There is big and difficult configuration on the switches or the fwsm.
Why does it behave like this?
The accessports are configured auto/auto and has 1000/full, the trunks is a dot1q trunks and the fwsm is permitting ip any any.
Could there be a bug in the fwsm (or is it related to the switches)?
Could it be some buffer problem in the fwsm? The configuration of the fwsm is rather plain allowing any-any ip.
server1(vlan650/vrf storage)-3560-6509-fwsm-6509-server2(vlan 670/vrf client)
The first 6509 has the fwsm installed.
Oh.. having the servers in the same VRF's og VLAN does not give this reduction in performance one way. Doing this makes good performance.