Hp 2930M - Bandwith errors

[_Thomas_]

Hi all,

I've got two 2930M switches with a 10 Gbit modules at the back.

I've connected on each switch a server with two 10 Gbit interfaces. When doing an iperf speed test, I get a maximum bandwith of 5 Gbit. That should be 10 Gbit? What could be the problem causing a half bandwith?

The setup is simple. I've got 2 VLAN's, DATA & BACKUP. Each interface of the server is in one of the two vlans.

Kind regards,

Thomas

[parnassus · Accepted solution]

So how are you testing iperf? two iperf server processes (each one on its VLAN) with respectively two iperf clients (each one on its VLAN)? or what?

[_Thomas_]

Just one iperf server and one iperf client. And then test.

[parnassus]

Mate, you should explain it a little bit better...if I understood you correctly...you performed an iperf client(s)/server test doing VLAN routing (depending on where you placed the iperf server and/or clients)...you hadn't tested iperf on each VLAN staying into each VLAN's boundary (so you forced your Switch to route the traffic between VLANs during your iperf tests, is that right?).

[_Thomas_]

Hi,

I'm testing iPerf on IP, so it stays between the VLAN boundaries.

Hopefully you have enough info.

Kind regards,

[parnassus]

Hi @_Thomas_ we all generally perform iperf Client/Server's tests using IP Addresses...so that doesn't mean nothing...if your iperf Server is on VLAN A and your iperf Client is on VLAN B and if IP Routing between those VLANs is enabled (and managed by your Switch) you're testing iperf Client/Server communication doing inter-VLAN Routing (using Switch routing Hardware/Software resources)...and this can have a performance (negative) impact on data throughput you experienced.

If this is not the case further diagnostic should be carried out on both sides (Host and Switch).

[_Thomas_]

Hi,

The client and server are in the same VLAN. So were are using the IP addresses in the same subnet.

Kind regards,

Thomas

[parnassus]

@_Thomas_you forgot to attach the configuration file you already attached on the Aruba AirHeads community thread (here): looking at it you're using a Smart Rate capable - AKA IEEE 802.3bz - module (exactly the Aruba 3810M/2930M 4 1/2.5/5/10 GbE HPE Smart Rate Module with Aruba SKU JL081A)...that 5Gbps limit probably sounds less strange now.

Redacted:

Running configuration:

; JL321A Configuration Editor; Created on release #WC.16.04.0008
; Ver #nn:nn.nn.nn.nn.nn.nn.nn.nn.nn.nn.nn.nn.nn.nn.nn.nn:nn
; encrypt-cred Nft4lYgEmtFDDOA09uxyOX0iFtQdJbGWqRCOyYV3EcHIQL4kRTCDZvOx3PKxedTE

hostname "Switch01"
module 1 type JL321A
flexible-module A type JL081A
timesync sntp
sntp unicast
sntp server priority 1 8.8.8.8
no telnet-server
time daylight-time-rule western-europe
time timezone 60
ip default-gateway 192.168.0.1
snmp-server community "public" unrestricted
vlan 50
   name "Backup"
   untagged A3
   tagged A1
   no ip address
   exit
vlan 111
   name "Servers"
   untagged A2
   tagged A1
   no ip address
   exit
spanning-tree
spanning-tree Trk1 priority 4
spanning-tree Trk2 priority 4
spanning-tree Trk3 priority 4
no tftp server
loop-protect all
loop-protect trap loop-detected
loop-protect disable-timer 60

So that can be a starting point to see if there is a relationship with speed limit(s) you see.

What is the output of show interface A2-A3 smartrate command for ports you used (I suspect A2 and A3)?

[_Thomas_]

Hi,

Sorry, I thought I attached it. I first thought indeed that the problem was a faulty negotiation of the smart rate capabilities.

I tried to put it static on 10Gb-full duplex, but still doesn"t work.

I also get 5.92Gbit/s, not a solid 5, I would expect.

Kind regards,

Thomas Willems

[parnassus]

At this point also outputs of show interfaces A1-A4 and a show show interface port-utilization (limited to A1-A4 ports) commands would help...

(Not) silly question: are Host<-->Switch patch cables (are you testing directly, isn't? I mean: not through a cabling distribution system...) Cat.6 (if link is shorter than 55 meters) or Cat.6A certified for use with 10Gbps links? Have you already played with cabling (trying STP or UTP as Cat.6/6A short Patch Cables?)