3com 5500 10GB link slower than 1GB Uplink

[l33byt1980]

Is there any reason when a switch to switch 10GB runs so much so slower than the 1GB spf fibre link.

When 10G is running we are getting 30K
When on 1G is running it is well over 150K

This is of course very rudementry however this is all I can see currently.

ACA - IPOffice implement
ACA - IP Telephony
CCNA - Passed at last

 

[MrNick0483]

What are you using to determine these speeds?

 

[jdoebling]

dont know if this will help or not, i just know it caused me big performance problems in the past:

1. spanning tree priorities across all switches from the edge to the core need to go from highest (edge) to the lowest (core) usually around 50000 to 8192.

2. unless you have carefully set up framesizes across all devices to handle extra large packets, you should also include this on the interface:
undo jumboframe enable
(This restricts any jumbo size packets and limits any unexpected packet fragmentation/defrag
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Also (and something to check first, even though it sounds jive) is to check the statistics on the sending and receiving ports on the two switches and make sure that the 10Gig link is not throwing errors on either side.

PS PS: What type of 10Gig XFP/Xenpak/Transceiver are you using on the two switches - I am assuming they match and are in 3Com specs for distance and media type (i.e. sm fiber needs 10Gbase-LR, mm is usually 10Gbase-SR -and only use mm on 50 micron fiber)

 

[blueshark101]

Normally jdoebling would be correct, however there's a known issue with frame size and the 10Gb modules.. . We had to enable jumbo frames at both ends in order to get them working correctly!

In most instances Jumbo frames are not encountered even when such things as 802.1p and/or Q in Q mechanisims are invloved even though this adds headers to the original Ethernet frame causing it to exceed it standard size from 1518 bytes to 1522. What happened was that 3Com set the registry to 1518 instead of 1522 on 10 GE I/F causing any frames with 802.1p and/or 802.1q headers to be dropped - by using Jumbo frames you circumvent the issue.

It is meant to be fixed in the latest firmware (3.3.1).

-Blue
The significant problems we face cannot be solved at the same level of thinking we were at when we created them

 

[l33byt1980]

Ah. I have seen some thing about the Jumbro frame issue else where.

What was the CLI string that you added to the 10Gb interfaces Blueshark101.

Thanks
Lee

ACA - IPOffice implement
ACA - IP Telephony
CCNA - Passed at last

 

[blueshark101]

It should be on by default...

The command is "jumboframe enable" and to turn it off is "undo jumboframe enable".

This should be run from the interface context..

interface TenGigabitEthernet1/1/1
jumboframe enable

To confirm run the "display interface TenGigabitEthernet1/1/1", part of the output should say "Allow jumbo frame to pass".


-Blue
The significant problems we face cannot be solved at the same level of thinking we were at when we created them