200M IP address significance

vmuser027 · 07-04-2020, 09:52

Hi everyone,

I'm relatively new again to the VM scene. I have 200Mb broadband and was for a time, using the SuperHub 3 in router mode with a BQM set up. Just for the record, I get 200/20 at all times of the day, no exceptions. The speed is fine.

Here is my BQM in router mode:

https://www.thinkbroadband.com/broad...215-25-03-2020

I then purchased an Ubiquiti Edgerouter-X for my network, as I already have some of their AP's, and I wanted some more visibility of traffic and also better DHCP/DNS control.

Once my Edgerouter-X was set up in place and my Superhub put into modem mode, I subsequently received a new IP address. I enabled a firewall rule for ICMP on the WAN, changed the IP on ThinkBroadband and my BQM resumed.

However, my BQM graph now looks weird:

https://www.thinkbroadband.com/broad...607-03-04-2020

I get blocks of higher ping (weirdly overnight) and I can make these 'calm down' again by rebooting the modem/router. For a time, and then it resumes.

My question is:
In router mode, I have one IP address which resolves to (made generic, ish) :
cpc123456-dudl14-2-0-cust123.16-1.cable.virginm.net

In modem mode, I have another IP address which resolves to (made generic, ish):
cpc987654-dudl14-2-0-cust789.16-1.cable.virginm.net

The bits in bold are different for each IP. My question is, am I routed differently when in each mode, i.e. am I seeing 'more congestion' on my modem mode IP? Do I get routed via different physical local hardware which either may have a problem or just more customers attached?

I'm jsut curious as to why it should be different. For now, I've moved back to router mode and turned the Edgerouter off. My BQM is back to normal, as expected, on my original IP.

Any ideas?

spiderplant · 07-04-2020, 10:30

I don't think you can tell from the DNS names. Have you tried a traceroute to the same endpoint in the two different modes?

vmuser027 · 07-04-2020, 14:56

Just done as you suggested. Took some tracroutes to 3 domains in router mode, then changed to modem mode and back in with the Edgerouter-X for some more traceroutes on the different IP.

traceroute to 1.1.1.1 done in router mode:

traceroute to 1.1.1.1 (1.1.1.1), 64 hops max, 52 byte packets
1 192.168.0.1 (192.168.0.1) 3.870 ms 2.386 ms 3.015 ms
2 X.X.X.X (X.X.X.X) 11.621 ms 12.465 ms 11.748 ms
3 wolv-core-2a-xe-706-0.network.virginmedia.net (80.3.146.25) 14.005 ms 22.002 ms 14.027 ms
4 * * *
5 tcma-ic-2-ae9-0.network.virginmedia.net (62.253.174.178) 16.215 ms 14.565 ms 18.044 ms
6 162.158.32.254 (162.158.32.254) 17.051 ms 15.546 ms 15.687 ms
7 one.one.one.one (1.1.1.1) 16.108 ms 15.569 ms 22.958 ms

traceroute to 1.1.1.1 in modem mode:

traceroute to 1.1.1.1 (1.1.1.1), 64 hops max, 52 byte packets
1 192.168.0.1 (192.168.0.1) 2.779 ms 1.429 ms 1.252 ms
2 X.X.X.X (X.X.X.X) 12.194 ms 11.734 ms 19.988 ms
3 wolv-core-2a-xe-714-0.network.virginmedia.net (80.1.80.41) 14.418 ms 21.841 ms 12.628 ms
4 * * *
5 tcma-ic-2-ae9-0.network.virginmedia.net (62.253.174.178) 20.520 ms 13.623 ms 13.969 ms
6 162.158.32.254 (162.158.32.254) 16.029 ms 16.397 ms 16.168 ms
7 one.one.one.one (1.1.1.1) 14.578 ms 14.222 ms 14.114 ms

So it appears that I am routed differently in modem mode once it reaches Wolverhampton. I removed the second hop on each as this was a private IP (Virgin 10.X.X.X) and was the same for each trace. I presume a very local routing device, so removed for privacy.

Is there any way that I can force a change of IP when I'm in modem mode? I presume that due to these different routes that's why I'm getting odd (and different) BQM results?

spiderplant · 07-04-2020, 16:06

I don't believe it's using a different route because you are in modem mode. It simply has multiple load-balanced routes from the CMTS and it's just a matter of luck which one it picks.

You might be able to get a new modem mode IP if you leave it in routed mode for a week so that the modem one expires. But there's no guarantee the new one would be any better.

vmuser027 · 07-04-2020, 19:51

Right, I've done a bit of Googling (and came across this forum a few times!) so I've cloned the MAC address of an old NAS I have lying around to my WAN interface on my Edgerouter-X.
This got me a new IP, which so far...seems to be all good and gives good BQM results. So I'm happy for now! I was worried it may be a problem with the Edgerouter but it seems it must just be the way VM's network works.

Thanks for your help!

adduxi · 09-04-2020, 10:19

Interesting thread. There are users on the VM Forums who swear they are being "hobbled" when using Modem mode. Once they go back to Router mode, everything is as it should. However, I've been using Modem mode for years and can't say I've noticed anything strange in my TBM.

Synthetic · 09-04-2020, 10:21

I believe it's "random" as it's based off the MAC which is different if you use your Edgerouter as the gateway or the SH3.

I've noticed the same thing but the other way round, with the SH3 in router mode my latency is higher and i get more hops to say 1.1.1.1, but in modem mode with my pfsense i shave off ~5ms / 3 hops to 1.1.1.1.

I think its probably just "luck" as to which IP you get and which route it takes

vmuser027 · 11-04-2020, 16:32

Still interesting...
Been in Modem mode for a few days, this is my BQM:
https://www.thinkbroadband.com/broad...98c-11-04-2020

(Ignore the high green bits, I was uploading to OneDrive)

This is a BQM from when in Router mode:
https://www.thinkbroadband.com/broad...98a-30-03-2020

Looks a lot better, average latency is lower.

The line performs fine when in Modem mode...speed is 220Mbps down and 21Mbps up. Pings to 1.1.1.1 are 10ms.

I've changed the MAC address on the Edgerouter WAN port about 8 times (to obtain a new IP), and each give exactly the same results (i.e, high average latency on the BQM)

I cannot fathom this one out!

---------- Post added at 16:32 ---------- Previous post was at 16:27 ----------

Quote:

Originally Posted by adduxi

Interesting thread. There are users on the VM Forums who swear they are being "hobbled" when using Modem mode. Once they go back to Router mode, everything is as it should. However, I've been using Modem mode for years and can't say I've noticed anything strange in my TBM.

Interesting, do you have a link to this or is it quite easy to come across if I head over to the VM community?

Kushan · 11-04-2020, 16:33

...could it be your Edgerouter that's the problem?

vmuser027 · 11-04-2020, 17:02

It could be and I'm not ruling it out. At the moment it just has out-of-the-box standard configuration with a WAN port set up with DHCP (to the Hub 3.0) and a LAN port to my LAN with DHCP enabled for 192.168.0.1/24, some basic NAT and that's it!

I'm running the latest firmware v2.0.8 hotfix 1 and did a search for any issues on Edgerouters like this but didn't come up with anything unfortunately. I could probably do with another router to test with but don't have one around until I can get back to the office!

**Paul** · 11-04-2020, 20:45

Ive been running modem mode for years and never had any speed issues.

Currently using a Linksys LRT224 (Dual Wan) as I have a backup ISP connection with Vodaphone.

vmuser027 · 12-04-2020, 06:56

Interestingly, I rebooted the Hub 3.0 lat night at about 10.30pm which you can see on the graph. The responses briefly go down to the levels you'd expect.
I then went to bed, then the connection was unused all night until 6.30am.
So what's with the low ping at 4am to 6am? All very weird!

https://www.thinkbroadband.com/broad...b31-12-04-2020

adduxi · 15-04-2020, 17:43

Quote:

Originally Posted by vmuser027

<snip>
Interesting, do you have a link to this or is it quite easy to come across if I head over to the VM community?

Sorry for the late reply, but this may be of interest

https://community.virginmedia.com/t5...4148554/page/4 - Message 37.