topic Re: two routers on my connection? in Tech Help - Software/Hardware etc

two routers on my connection?

gerry49 — Mon, 14 Jul 2025 16:34:18 GMT

I am setting up a synology nas on my network and the nas is telling me there are two routers on my network and they need to be bridged. There is only one router in my house. I have found out that there can be a second router somewhere next down my line possibly in an exchange. I have carried out a trace route test and have come back with possibly the second router. My router ip is 192.168.1.XXX and the next ip down the line is 172.16.15.58 and 172.xxx.xxx.xxx is usually another router.

How can i get these routers put into bridging mode?

Re: two routers on my connection?

Dan_the_Van — Mon, 14 Jul 2025 16:57:54 GMT

@gerry49 welcome to the forum.

Can you share the traceroute output please?

plusnet do use some 172 addresses so it might be a false result

EDIT: does the NAS have a cli? if so if possible traceroute from the NAS

Re: two routers on my connection?

gerry49 — Fri, 18 Jul 2025 15:02:20 GMT

Thanks for the reply.

Here is the result from my traceroute test.

Tracing route to dns.google [8.8.8.8]
over a maximum of 30 hops:

1 <1 ms <1 ms <1 ms 192.168.1.254
2 3 ms 3 ms 3 ms 172.16.15.58
3 * * * Request timed out.
4 8 ms 7 ms 7 ms 132.hiper04.sheff.dial.plus.net.uk [195.166.143.132]
5 8 ms 8 ms 32 ms peer3-et0-0-4.slough.ukcore.bt.net [194.72.16.58]
6 8 ms 8 ms 8 ms 109.159.253.75
7 9 ms 10 ms 9 ms 74.125.253.31
8 10 ms 9 ms 9 ms 216.239.63.219
9 9 ms 9 ms 8 ms dns.google [8.8.8.8]

Trace complete.

Moderator's note by Mike (Mav): Post released from Spam Filter.

Re: two routers on my connection?

gerry49 — Thu, 17 Jul 2025 13:35:53 GMT

I posted the traceroute from my pc but it looks like it has not posted on here. Can anyone see it? I will do another one when i,m at my PC later.

Wondered why i did not have a response.

Re: two routers on my connection?

Dan_the_Van — Thu, 17 Jul 2025 14:40:35 GMT

Hi, some posts sometimes get marked as spam, which might explain it's non arrival.

Re: two routers on my connection?

MisterW — Thu, 17 Jul 2025 14:57:44 GMT

@gerry49 and the next ip down the line is 172.16.15.58 and 172.xxx.xxx.xxx is usually another router.

The 172... address is not a router its the BT gateway. Since its the other end of your PPPoE connection there's no need for it to have a publicly routable address and so BT wholesale use the 172... for gateways on their WBC (Wholesale broadband connect) network.

As @Dan_the_Van says, the NAS is making a false assumption that a 172... address is a router

Re: two routers on my connection?

gerry49 — Thu, 17 Jul 2025 16:31:38 GMT

Ah, ok thanks. I,ll fire up the pc and do the trace route.

Re: two routers on my connection?

gerry49 — Thu, 17 Jul 2025 16:36:40 GMT

Done it on this laptop. Same result.

Tracing route to dns.google [8.8.8.8]
over a maximum of 30 hops:

1 404 ms 7 ms 2 ms 192.168.1.254
2 44 ms 31 ms 47 ms 172.16.15.58
3 * * * Request timed out.
4 154 ms 216 ms 66 ms 132.hiper04.sheff.dial.plus.net.uk [195.166.143.132]
5 13 ms 18 ms 47 ms peer3-et0-0-4.slough.ukcore.bt.net [194.72.16.58]
6 15 ms 25 ms 10 ms 109.159.253.75
7 23 ms 130 ms 201 ms 74.125.253.31
8 13 ms 433 ms 201 ms 216.239.63.219
9 21 ms 230 ms 310 ms dns.google [8.8.8.8]

Trace complete.

Third one always times out. 1. Is the router here, 2. is the one i suspect is the second router elsewhere.

Re: two routers on my connection?

jab1 — Thu, 17 Jul 2025 16:41:35 GMT

That second address is not a router as such - it is the gateway address to the WBC, and therefore nothing to do with you or your internal network.

Re: two routers on my connection?

gerry49 — Thu, 17 Jul 2025 16:47:19 GMT

Thanks for the info. So i guess i will have to set up the Nas manually. That should be fun.

Re: two routers on my connection?

Dan_the_Van — Thu, 17 Jul 2025 16:49:09 GMT

@gerry49

The traceroute is very much as I expected it to be, as I said a false result.

Re: two routers on my connection?

gerry49 — Thu, 17 Jul 2025 17:06:11 GMT

Just looked at the router setup on the nas again and it says " we will help you setup a connection between your nas and the router. before the setup.

It will take a while to run the checklist below.

Checking network interface

Checking gateway connection

checking network connection

checking DNS Server

Checking network environment

Detect router information

Everything is ok except checking network environment.

This message appears

"Two or more routers were found in your network. Consult your ISP to set the modem/ router to bridge mode. or try setting your router to bridge mode."

Could it be seeing my switch as a network router. Router is connected to a switch and everything goes from that.

Could the "IN" be the clue?

Re: two routers on my connection?

Champnet — Thu, 17 Jul 2025 17:24:48 GMT

I’ve a couple of Synology boxes and setup many others but never seen that message.

Probably cause I configure the network setting manually and it looks like you’re using an automatic process ?

Re: two routers on my connection?

Dan_the_Van — Thu, 17 Jul 2025 18:27:24 GMT

@gerry49

I very much doubt a switch would be detected as a router, the ones you are using would need a IP address which would really only be used for management purposes not routing, the 172. IP Addresses from your traceroute are outside of your home network.