Re: [Devil-Linux-discuss] VLAN & routing. Poor performance

[John J. <jj...@ro...>]

Hi m,

Thank you for taking time to respond to this, not sure if I understand,
but if you are asking if I've tested with two nics' both in "VLAN mode".
I had not tested this.

Good point btw. I've now tested this too, and performance is good with
SMB traffic in this setup.

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#4 below would therefore be:

Two NIC's, both in VLAN mode, map/browsing of shares from a machine on
one side to a machine on the other, speed is good/normal.

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Seems to me traffic flows normal when both cards are in the same "mode".
Not sure why this is? I've searched high and low on google, but could
not find this issue documented. This leads to me to think it's not a
common problem, but as "many" (unsubstantiated claim by me) people use
VLAN's in Linux, could it be a problem with this specific kernel/build
etc?

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JJ

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From: dev...@li...
[mailto:dev...@li...] On Behalf Of
Martin Hotze
Sent: 12. august 2007 10:33
To: dev...@li...
Subject: AW: [Devil-Linux-discuss] VLAN & routing. Poor performance

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and what happens if you use 2 VLANs, both tagged or one tagged and one
untagged? At least you would do so in the switching world.

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#m

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________________________________

Von: dev...@li... im Auftrag von
John Jore
Gesendet: Sa 11.08.2007 21:47
An: dev...@li...
Betreff: [Devil-Linux-discuss] VLAN & routing. Poor performance

Hi!

I've got a VMware VM with 2 NICs, vmxnet/e1000's.  On each side there is
another VM running Windows. I map and browse a share on one from the
other, using the DL VM as a router.

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1: When both NICs are running in "normal" mode, no VLANs, speed is
good/normal.

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2: When one NIC is running as "normal" and one as a VLAN card, (vmxnet
and e1000 both support this). Speed is horrible and barely works. I can
browse the root of the share, but it soon times-out and can't browse the
share and looses all SMB connectivity with the host. Ping seems to be ok
though, with both small and large packets.=20

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3: Remove/disable one NIC and run all traffic as VLAN traffic over the
remaining card (router-on-a-stick): Speed is good/normal.

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What is going on?!? And why am I seeing this? I'm using version 1.2.13
of DL.=20

To repeat myself just in case: When a packet arrives on the normal NIC
and gets routed to the VLAN'ed NIC and exits DL performance is horrible.

Could there be a problem with the Linux kernel version when doing
routing from a "non-VLAN'ed" NIC to a "VLAN'ed" NIC? The configuration
of the nic's themselves can't really be wrong as Ping works, end-to-end.
I've tried reducing the MTU as some sites have suggested, but did not
solve anything. Also, I do not think neither vmxnet or e1000 have the
MTU problem with VLANs.

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Anyone have any suggestions?

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Regards,

John Jore

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PS: The firewall was enabled, but it's not doing much, and it's
configuration did not change between these three setup's (enabled
traffic on all interfaces, both vlan's and physical and filtered on IP
addresses only) I would therefore not blame it in this case.

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