Hi Raf, Can you share with us which SDWAN vendor it is? I've tried 4 different ones with ACS and they all worked fine, in all cases what I did was to set the MTU in the SDWAN appliance to be a bit lower than 1500 (in between 1422 and 1460, depending on SDWAN solution). In most network you'll end up with most of your traffic with an MTU of around 500-600 anyway, so larger MTU doesn't help that much, I'd highly recommend you run some traffic analysis to try to figure out what's the MTU distribution for your network traffic.
With that said, I also had to change the MTU in VRs for a proof of concept on iSCSI between datacenters, in that situation I just wrote a script that would login to each VR and change the MTU of the public and private interfaces, it worked OK. I would strongly advise you not to change the MTU of the management interface, when I did (by mistake) the VRs lost communication with the management server. If you want to contribute by expanding cloudstack code to add a setting for VR MTU I'd be more than happy to collaborate with you on that. Hope this helps. Cheers, Alex alex.matti...@shapeblue.com www.shapeblue.com 3 London Bridge Street, 3rd floor, News Building, London SE1 9SGUK @shapeblue -----Original Message----- From: Rafael del Valle <rva...@privaz.io.INVALID> Sent: 24 March 2021 10:33 To: us...@cloudstack.apache.org Cc: us...@cloudstack.apache.org; dev@cloudstack.apache.org Subject: Re: RE: Virutal Router MTU Hi Alex, In our particular use case the Public Network is an SD WAN and we have a requirement of slightly smaller MTU than the standard 1500. I have assumed that our traffic will be encapsulated into something else before delivery, I guess that is the reason for the requirement. What would be the easier way to add support for MTU tunning on VRs? I would be to contribute and implement it. Regards, On Wed, 2021-03-24 09:39 AM, Alex Mattioli <alex.matti...@shapeblue.com> wrote: > Hi R, > > There's no ACS setting for the VR's MTU size. > Unless you are running storage traffic s in that network then jumbo frames > aren't of much use. I've ran some tests at the request of some customers in > my previous job, and with some very busy VRs and the performance gains for an > MTU of 9000 were statistically insignificant. > If your VRs are saturated your best option is to increase the > resources for its offering (if you need guidance with that, am happy > to provide it) > > Anyway, what's your use case for jumbo frames? > > Regards, > Alex > > alex.matti...@shapeblue.com > http://www.shapeblue.com > 3 London Bridge Street, 3rd floor, News Building, London SE1 9SGUK > @shapeblue > > > > > -----Original Message----- > From: rva...@privaz.io.INVALID " > target="_blank"><rva...@privaz.io.INVALID> > Sent: 24 March 2021 09:23 > To: us...@cloudstack.apache.org > Subject: Virutal Router MTU > > Hi! > > I can see in the Global Parameters that it is possible to specify the MTU for > secondary storage VM. > > Is it possible to configure the MTU for a virtual router? how? > > Regards, > R. >
