Linksys MX12600 and Sky Hub SR203

jerryjal

Well-known Member
I have finally found a mesh system that actually does a decent job at my home in the Linksys Velop MX12600, I am using it in conjunction with the Sky SR203 hub on the Ultrafast 500mbps service.
The only downside I am seeing at the moment is double nat on my sons Xbox, I have very limited knowledge with networking but from what I have found it is because the Linksys system is directly connected to the SR203 router so it is giving off a double nat. I have turned off the wifi on the router to make sure that there is as little interference as possible and I have discovered that it is impossible to put the SR203 in to modem mode so the way I see it I have two options, unless of course someone out there with greater knowledge than I (that won't be hard!) knows of a different solution?

Option 1. I am not sure if this is even possible but is it possible to connect the main Linksys node directly to the internet supply instead of the SR203 and get that to act as the main router?

Option 2. Is it possible to replace the SR203 with a different (something like a TP Link) router and set that up and then turn that router in to modem mode?

I have tried several different mesh systems, all with varying degrees of success but this one seems to actually work and keep my wifi speed to over 250mbps even at my bedroom on the third floor and out by the garage where I need it for connection to my Tesla.

Any advice would e appreciated and thanks in advance.
 

mickevh

Distinguished Member
Dual NAT occurs simply because you have two devices in the pathway that are both performing NAT translation. It isn't a problem in and of itself (and happens more than you might realise) but it does screw up some applications in the SOHO use case that want to discover your public IP address e.g. some online games. Dual NAT (and two routers) also adds some additional latency (lag.)

The simplest solutions is to do away with one of your routers and just have one thing that is routing/NAT/firewalling. I would use the ISP router to do this, just turn off it's Wi-Fi if you don't want to use it, it's rarely more than a couple of clicks - there's no need to put a router into "modem mode" to disable it's Wi-Fi - "modem mode" (for those routers that offer it) is to address something else.

Thence instead of using the Velop system as a router, put it into "bridge" mode (or it may be called "AP mode.") That will turn off the router/NAT/firewall in the Velop and leave it "just" functioning as a fleet of managed Wi-Fi AP's. Technically, Internet traffic will be a tad faster and lower latency in this configuration, (as it is transitting one fewer router/NAT/firewall,) though whether you can measure, let alone "notice" the difference is a moot.

Having changed the Velop to bridge mode, your internal IP addressing will be in a mess for a while whilst the DHCP leases assigned by your Velop time out and get replaced by new ones from the Sky router. If you leave it all alone for 24 hours, it'll sort itself out as the automation in DHCP does it's thing - power cycling all the client devices my expedite the process. Also, their IP addresses may change.

Wi-Fi is facilitated by "Access Points" (AP's) not "routers" - this isn't just hair splitting over nomenclature, in the field of data networking a "router" and an "AP" are very different things. It just so happens that the typical SOHO "get-you-on-the-internet" omni-box contains both (and much more besides.) Routers sit at the "edge" of a network connecting to other networks (ie the public Internet in the SOHO use case) not in the "middle" bossing it. For SOHO use, you really only need one router and it may as well be the one the ISP provided. There are good reasons why one might change out an ISP router for something else (as a forklift replacement) but "fixing" a Wi-Fi problem is rarely such a reason.
 
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jerryjal

Well-known Member
Thank you for such a detailed response, I have already disabled the wifi on the ISP router.
The only thing stopping me putting the Velop that is attached to the SR203 by ethernet in to AP mode is the loss of features if I do it, it is handy to see what devices are online and I lose that functionality if I put it in AP mode.
Nice to hear the response regarding double nat, I will leave the system as is at the moment then and not worry about replacing the Sky router, it is a shame that the SR203 can't just replaced by the Velop but do understand why.
 

mickevh

Distinguished Member
If you leave both your routers routing, then your network is partitioned into two "sub-nets" (in the jargon of IP networking.) You can kind of think of it as an "outer" and an "inner" network with the Velop being the demarcation/boundary between the two.

That will certainly "work" (in some bigger networks it's a configuration we use to create a demiltarised zone (DMZ,)) but what you will probably find is there are issues with devices in each network talking to each other. Principally, devices connected to the outer subnet won't be able to initiate communications with anything connected to the "inner" network unless you set up Port Forwards and the like. If you have nothing connected to your "outer" network, then it's no big deal.
 

jerryjal

Well-known Member
Thank you for that.

I changed the Velop in to AP (Bridge mode) and the speeds increased even more and everything was stable. The major downside to this was that the Sonos system and more importantly the car (Tesla) would no longer connect to the Wi-Fi, previously when the Velop was in router mode the connected without issue.

I definitely prefer the speeds and stability of the Velop in Bridge mode but need to be able to work out how to get the car and Sonos to connect.

Any ideas?
 

mickevh

Distinguished Member
It's possible an issue with IP addresses previously assigned by the DHCP Server in the Velop needing to time out and be replaced by new leases from the Sky router. It's probably a bit difficult to reboot a car to force it, so I suggest leave it for 24 hours and see if the automation of DHCP sorts it out for itself. If not, check back and we can investigate further.
 

Colintoo

Novice Member
I have almost exactly the same issue. I have swapped out a very old linksys router for the Velops. My old set up had both my EE router and my linksys set up as routers. I have followed the advice here and now use the EE router for routing and the Velops are set up in bridge mode. The set up was incredibly simple and hassle free with one exception. I have a Sony tv running a Google os which has connected to the new wifi perfectly, has been assigned an ip, MAC address etc and says it connected perfectly but the wifi connection connected has no internet access. No other device has this problem. I have rebooted the tv, removed power and reconnected and told it to forget the network and reset the connection but it still claims it has no internet connection.
Any suggestions?
I hope I’m not hijacking’s this thread but the issues seemed very similar…
 

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