Solved: RV180 not getting gigabit/1000 speed on WAN port

eric.jack · ‎12-22-2013

I have my RV180 connected to a Motorola SB6121 cable modem on the WAN port. The modem indicates that the connection to the router is only 10/100. If I plug my laptop directly into the cable modem, it then indicates that the connection is full gigabit.

On the RV180 configuration, under Networking > Port Management, the WAN (Internet) port is Enabled, and set to Full Duplex and 1000 Speed. Auto Negotiation and Flow Control are unchecked. I've also changed the WAN port to Auto Negotiation and rebooted the RV180. But none of these settings seem to affect the detected speed on the modem's end. It always shows an amber Link light, which indicates 10/100Base-T instead of a blue Link light which indicates full 1000Base-T.

Am I missing another setting somewhere, or is there any other reason why the modem insists that the connection to the router is only 10/100?

Leo Laohoo · ‎01-10-2014

If I plugged my laptop into the RV180 rouoter's WAN port, I do not see how that would be a proper test.

Are you then using two different cables? The reason why I'm asking because there are some "shonky" Cat5/Cat6 cables which are not properly terminated. If these are properly terminated cables, you can get 1 Gbps. If not, you're going to get 100 Mbps.

View solution in original post

eric.jack · ‎12-30-2013

Well, I received a system email saying that Satish Chandran replied to this post, but for the life of me I don't see the reply anywhere! I'm still hoping to find a solution to this annoying problem.

Regards,
Eric

eric.jack · ‎01-06-2014

I still need some ideas on this. I've made sure the firmware is updated and it had no difference. The modem still indicates a 10/100 connection when the RV180 is attached, but not when I connect my laptop directly to the modem. Help!

mpyhala · ‎01-06-2014

Eric,

If you plug the modem into a LAN port on the router does it negotiate properly? I have seen a few (rare) cases where the modem and router will not negotiate at 10/100/1000 under any circumstances. It appears to be a hardware incompatibility. In that case the only choice is to replace one device or the other. I have used a Cisco DPC3010 with the RV180W and RV220W and it worked great at Gigabit speed. I have not personally tested a Motorola modem with either router.

- Marty

eric.jack · ‎01-10-2014

Plugging the modem into one of the four LAN ports on the RV180 made no difference. The modem still showed the connection as 10/100. I like the RV180 and would hate to replace the modem because I bought both brand new at the same time after a power surge toasted most of my home network (insurance paid.)

Leo Laohoo · ‎01-10-2014

If I plug my laptop directly into the cable modem, it then indicates that the connection is full gigabit.

This may come to you as a funny question but "humour me" for a bit.

Is this the same cable from the Moto modem to your RV modem? If the answer is yes, can you connect your RV modem's WAN port to your laptop and determine what the outcome is?

eric.jack · ‎01-10-2014

I'm not sure I follow your reasoning.

When I plugged the laptop directly into the Motorola modem, it was using a different Cat-5 cable. The RV180 router is connected to the modem via a very short Cat-5 cable normally.

If I plugged my laptop into the RV180 rouoter's WAN port, I do not see how that would be a proper test. The modem would then have nothing connected to it, and my laptop/network would not have internet access.

Leo Laohoo · ‎01-10-2014

If I plugged my laptop into the RV180 rouoter's WAN port, I do not see how that would be a proper test.

Are you then using two different cables? The reason why I'm asking because there are some "shonky" Cat5/Cat6 cables which are not properly terminated. If these are properly terminated cables, you can get 1 Gbps. If not, you're going to get 100 Mbps.

eric.jack · ‎01-13-2014

Interestingly, I think you nailed it. I would not have thought to check the cable since it "worked". But when I used a different Cat-5 cable between the RV180's WAN port and the cable modem, the link light on the modem immediately showed a GB connection. Typically, when I've seen a bad cable, it doesn't work at all. And what surprises me is the cable I used is the short 8-12" cable that came in the box with either the modem or the RV180.

I'll have to test the cable, as I'm curious how it could be bad but still work as well.

Leo Laohoo · ‎01-13-2014

I'll have to test the cable, as I'm curious how it could be bad but still work as well.

Typically, a data cable requires a minimum of two pairs working. First pair is for Layer 1 signalling to begin. The next one is Layer 2 and this is also the pair which dictates your line speed. If you have two pairs working then you are guaranteed 100 Mbps (ok, don't drag me into a cable in excess of 100 metres).

Now for GigabitEthernet, you need a minimum of three pairs. The third pair is the GigabitEthernet "controller". This is the main reason why I'm asking how many cables are you using to test.

Do me a favour and do not say something like, "but the cables came from a sealed pack". I don't care. I have seen so many "sealed pack" of cables which won't work because they were shonky. One, two or three pairs of wires are terminated incorrectly or not at all terminated. I'm not talking about from one manufacturer. I've used a lot.

Leo Laohoo · ‎01-13-2014

A majority of these no-name-brand or brands-you've-never-heard-of cables are manufactured in some inhospitable backyard operation. Their so-called "quality control" is a tester which tests only two pairs (because they are cheap). So if you plan to use these so-called "GigabitEthernet ready" cable and they have the 3rd pair not properly terminated, the shop will always blame your network.

eric.jack · ‎01-14-2014

Well, here's the odd thing: The cable tests fine when I use the tester. All four pairs show correct. I'm pretty sure this 12" cable came with either the RV180 or the modem itself. So I have no idea why a cable that tests fine is causing the problem I was experiencing.

In the end, it doesn't really matter I guess. I solved the problem by using a different cable. But it still boggles me, and makes for some difficult troubleshooting when a "bad" cable tests "good" except for when actually used.

mpyhala · ‎01-14-2014

Eric,

Can you read the text on the cable? If it reads "CAT 5e" or above (CAT 6, 7) it should support 10/100/100 (Unless it is defective, and yes it happens much too frequently). I have found that some CAT 5 cables will pass traffic at Gigabit speeds but many have issues and are limited to 10/100 only.

The 12" cable likely came with your modem. The Cisco routers ship with a 36" cable, usually tan or gray in color.

Leo: Nice catch, we often forget about cables when troubleshooting these type of issues.

- Marty

Leo Laohoo · ‎01-14-2014

Nice catch, we often forget about cables when troubleshooting these type of issues.

Thanks, Marty.

I wouldn't have seen this thread and I wouldn't have responded. I just clicked on to this thread by mistake.

In regards to cable, yes. I see this all the time all across the forum, from phones to wireless to networks. In the Catalyst side of appliance, Cisco (and a lot of manufacturers) now support TDR.

Leo Laohoo · ‎01-14-2014

 All four pairs show correct.

I have personally tested a number of these so-called "testers". They claim to test all four "pairs" when, in fact, they just test four PINS (aka two pairs).