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items: Awful proxy_arp performance
items: Re: Awful proxy_arp performance

Awful proxy_arp performance
type: item
description: Hi I have the following setup: - Debian Lenny 5.0.1 - Pre-built Debian kernel: linux-image-2.6.26-2-openvz-amd64, version 2.6.26-15 - Standard venet0 routed setup, with ip_forward and proxy_arp enabled I'm experiencing an awful proxy_arp performance. ARP requests from a random host on the LAN (let's call it host A) to any VE running on this server, which we'll call host B, take between zero and 800ms to complete. See a frequency graph of 1000 tests, below. ARP requests from host A to host B (not to a VE) are near-istantaneous (<1ms) as are subsequent pings from A to the VE, after ARP resolution has taken place. Is there a way to fix this problem without resorting to a bridged veth setup? In case you want to run the test on your own, here is what I did to measure the times, in Bash: h=192.168.10.7; for ((i=0; i<1000; i++)) do sudo arp -d $h; ping -nc1 $h | awk -F'[ =]' '/bytes from/ {print $10}'; done > times.csv
creator: tobia
date: 2009-07-03T15:43:58-00:00

Re: Awful proxy_arp performance
type: item
description: I solved this issue using veth instead of vnet and bridging all the veth* together with eth0. Configured this way, ARP requests are back to a reasonable average of 3ms. I would still like to know if it can be solved any other way. Isn't vnet supposed to be more efficient than veth?
creator: tobia
date: 2009-07-06T10:52:01-00:00

Re: Awful proxy_arp performance
type: item
description: tobia wrote on Mon, 06 July 2009 12:52 I would still like to know if it can be solved with vnet Anybody??
creator: tobia
date: 2009-07-28T08:07:57-00:00