https://markandruth.co.uk/2016/08/08/testing-the-performance-of-the-linux-firewall
Does not directly address marking but does benchmark a number of
iptables filtering tasks which may give some insight into the
performance implications of using iptables for routing and filtering.
https://www.digitalocean.com/community/tutorials/a-deep-dive-into-iptables-and-netfilter-architecture
A nice article on iptables. No performance info but a good read for
anyone who needs to tackle routing and marking.
https://www.markusschade.com/papers/firewall.pdf
Has some performance info and a discussion about the host limit with MARK.
I am a bit skeptical that MARK adds a lot of overhead but this is only
based on the belief that CPUs are orders of magnitude faster than networks.
The decision process on entry and exit are both pretty simple and
depending on the implementation of the internal table should not take a
lot of memory of CPU to do the table lookups
I did not read all 60,400 links returned by Google but in the ones that
I did read did not warn of any big problem with performance using MARK.
I use a simple static MARK configuration in my firewall to solve a
routing problem but the performance requirements are not relevant to an
datacentre with hundreds of CPUs and hundreds of entries in the MARK
routing map.
I hope that this helps.
Ron
On 20/04/2018 9:04 AM, Rohit Yadav wrote:
Thanks Jayapal. I don't have any comparative study yet, but I'll explore this
in future if we can get away without marking (mangling) packets which is
generally an expensive task.
- Rohit
<https://cloudstack.apache.org>
________________________________
From: Jayapal Uradi <jayapal.ur...@accelerite.com>
Sent: Thursday, April 19, 2018 10:33:25 AM
To: dev@cloudstack.apache.org
Cc: us...@cloudstack.apache.org
Subject: Re: [DISCUSS] Why we MARK packets?
Rohit,
My comments inline.
rohit.ya...@shapeblue.com
www.shapeblue.com
53 Chandos Place, Covent Garden, London WC2N 4HSUK
@shapeblue
On Apr 19, 2018, at 1:52 AM, Rohit Yadav
<rohit.ya...@shapeblue.com<mailto:rohit.ya...@shapeblue.com>> wrote:
Nevermind, found the use of custom routing tables. In case someone want to
refer, hints are here:
https://github.com/apache/cloudstack/pull/2514#issuecomment-382510915
Jayapal and others - I've another one, is there a way to do routing without
marking packets at all, even in case of VRs with additional public interfaces?
AFAIK marking is the only way to do it.
Do you have any performance numbers with and without mark rules.
- Rohit
<https://cloudstack.apache.org<https://cloudstack.apache.org/>>
________________________________
From: Rohit Yadav <rohit.ya...@shapeblue.com<mailto:rohit.ya...@shapeblue.com>>
Sent: Wednesday, April 18, 2018 10:39:02 PM
To: dev@cloudstack.apache.org<mailto:dev@cloudstack.apache.org>;
us...@cloudstack.apache.org<mailto:us...@cloudstack.apache.org>
Subject: [DISCUSS] Why we MARK packets?
All,
I could not find any history around 'why' we MARK or CONNMARK packets in mangle
table in VRs? I found an issue in case of VPCs where `MARK` iptable rules
failed hair-pin nat (as described in this PR:
https://github.com/apache/cloudstack/pull/2514)
The valid usage I found was wrt VPN_STATS, however, the usage is not exported
at all, it is commented:
https://github.com/apache/cloudstack/blob/master/systemvm/debian/opt/cloud/bin/vpc_netusage.sh#L141
Other than for debugging purposes in the VR, marking packets and connections I
could not find any valid use. Please do share if you're using marked packets
(such as VPN ones etc) outside of VR scope?
I propose we remove MARK on packets which is cpu intensive and slows the
traffic (a bit), instead CONNMARK can still be used to mark connections and
debug VRs without actually changing the packet marking permanently. Thoughts?
- Rohit
<https://cloudstack.apache.org>
rohit.ya...@shapeblue.com<mailto:rohit.ya...@shapeblue.com>
www.shapeblue.com<http://www.shapeblue.com/><http://www.shapeblue.com<http://www.shapeblue.com/>>
53 Chandos Place, Covent Garden, London WC2N 4HSUK
@shapeblue
rohit.ya...@shapeblue.com<mailto:rohit.ya...@shapeblue.com>
www.shapeblue.com<http://www.shapeblue.com/>
53 Chandos Place, Covent Garden, London WC2N 4HSUK
@shapeblue
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