Help request: configuring a DD-WRT router with VM cable?

christopherw · 25-06-2007, 23:42

This is doing my nut in.

I'm a new VM subscriber on XL, and have a (crap) Scientific Atlanta EPC2100R2 cable modem. When it was first set up, I temporarily plugged my laptop into the router's (only) ethernet socket, only to subsequently realise that of course, VM has registered my laptop's ethernet MAC as the only allowed device on the network.

However, I have more than one PC I want to use - simultaneously - on the network, and my housemates are in a similar situation (we all pay, so we all get to use I guess!) I have a Linksys WRT54GL router running the open-source DD-WRT firmware - which has worked beautifully for the past year as a simple switch with our Be* service (we switched because our phone line will only give us just under 10mb whereas Brum is getting 20Mb in July).

However, whatever I try, once I've cloned the MAC address of my laptop onto the DD-WRT router (to enable it to access the network), I can only get the router to be assigned an IP from Telewest - I can make it pass on DNS information so computers can resolve IP addresses, but traceroutes don't work and for some reason I can't make the router transparently pass on outgoing and incoming data to the SciAtl router (the DD-WRT tries to tell any machines connected to it to use itself as the default gateway, so of course any requests for web pages or anything else just fails).

Is there anybody around here who has experience setting up DD-WRT routers to work with VM service? I'm really struggling to make it work here, and it's a bit of a problem because if I can't get it to work, nobody else in the house has Internet access! Bit of a pain (and I get an earful from all 5 of my other housemates).

Is there something I'm missing in the router config? All I've done is cloned the MAC address to make it work on the network, and set the DD-WRT router as a DHCP server because the Scientific Atlanta doesn't seem to have any kind of routing capabilities and directly assigns the machine plugged into the ethernet socket with the public-facing IP address of the VM connection as seen by the greater Internet. Without a PC plugged into the modem, the modem won't even respond to ping requests via the Internet!!! How crap is that...

Please help! I'm going absolutely spare, and I SERIOUSLY doubt VM support will want anything to do with this kind of support. I'm hoping there's some sufficiently-techy bods who can help me out on this one, I really don't want to spend weeks and weeks tearing my hair out when I'm most likely missing something dead obvious which would take five clicks to fix!

Cheers in advance...

MovedGoalPosts · 25-06-2007, 23:51

Your right about VM support - they won't help you with routers.

Odd that you needed the mac of your laptop to be set into the cable modem, I thought that was recorded only for Set Top Box users.

You are fully powering the modem off before you change over the connected device - laptop to router?

I'd suggest you do a factory reset on the router, get it all back to it's default settings. Then you should be able to proceed normally.

christopherw · 26-06-2007, 00:12

I'm heading back up to Brum in about 10 minutes (came back to my rents' house as I had a job interview nearby earlier today) so when I get back I'll give that a go.

Gareth · 26-06-2007, 00:50

I'm running the same firmware and router but with a different modem (the blue 250 thingy). Mine works a treat, so if you want me to post my config screens just gimme a shout... bearing in mind I work during the daytime so can only post in the evenings.

christopherw · 26-06-2007, 03:19

Quote:

Originally Posted by Gareth

I'm running the same firmware and router but with a different modem (the blue 250 thingy). Mine works a treat, so if you want me to post my config screens just gimme a shout... bearing in mind I work during the daytime so can only post in the evenings.

That'd be absolutely smashing mate - I'm losing what little hair I have left (poor genes, didn't get much to start with) over this issue, and I really haven't a clue where to start as I'm a comparative noob with cable modem-related issues

Out of curiosity, here's my l8nc graphs for the past three days...

(large amount of red is where the modem was not plugged into any device, as I was moving stuff around in my room at the time, and the several largish chunks of red are where I was either changing cables or unplugging and replugging in the modem.)

(reason the graph cuts off is because that's the current time as I post this!)

By comparison, here's my Be* connection for the past 26 hours:

(the higher latency is when uTorrent's been seeding)

I don't like the look of all those spikes, and WOW the amount of loss during the peak hours - surely that can't be normal?! My downstream is 2.9dBmV and 41.2dB SNR and my upstream is 35dBmV, so I don't *think* they're problematic (it's a brand new install which was spliced onto an existing cable (12 months old) running to the annexed flat behind the house)... Is this just "one of those things" I'll have to put up with during peak hours or should I have a whinge to the VM 'tech support' before it becomes 25p/min?

Gareth · 26-06-2007, 22:04

Sorry for delay, mate.... here's the screenshot.

Gimme a shout if you want screenshots of the other pages.

christopherw · 26-06-2007, 22:27

Very useful mate, though I'm curious as to how your other screens look - notably the Basic Setup page as that seems to dictate most of the subsequent connection settings for any connected devices... Also pages like the Advanced Routing tab (if you made any custom configs specific to VM), and whether stuff like the Routing option was enabled in Administration -> Management... I'm really trying to nail what the problem is here.

Wicked_and_Crazy · 26-06-2007, 22:49

AsGareth is offline, my basic setup page looks like this

christopherw · 26-06-2007, 22:57

Was your DD-WRT router the first thing you plugged into your modem?

You running a scientific atlanta EPC2100R2 like I am? (just trying to eliminate variables)

Wicked_and_Crazy · 26-06-2007, 23:03

I have a different modem. I used to have my PC plugged into the modem and no router.

When i changed to a router i powered down the modem, powered it up with nothing connected, plugged the router into the modem and power that up, then finally powered up the PC.

---------- Post added at 23:03 ---------- Previous post was at 23:02 ----------

when you reboot the PC does it all work fine for a while and then suddenly slow down?

Have a look at solution 1 on this page. I had to do this after i installed DD-WRT

http://www.dd-wrt.com/wiki/index.php/Router_Slowdown

christopherw · 26-06-2007, 23:03

aarrrggghhh... my router is configured IDENTICALLY to yours, I've unplugged it, rebooted the router and then plugged it back in again after a few minutes... it's not made a bit of difference.

I can access my router fine, and I can ping my modem's own IP (the 82. address) as well as 192.168.100.1, one thing I have noticed on the Status page is that for every IP lease the router's given my laptop (I've /released and /renewed a couple of times) it lists my PC, connected to Ethernet, with the router's MAC address - once for the 82.36 external address, and three more entries on the local network...

The most annoying thing is that downstairs has a linksys wireless router hooked up to their scientific atlanta modem, and I can connect to that and view my ipconfig stats just fine - and they look exactly the same as mine (when I turn dnsmasq off for dhcp and dns that is, otherwise 192.168.1.1 is shown as the DNS server)... Yet for some reason only their router shows up in the Status page, and my machine doesn't show up as well!

This is REALLY bizarre, and it's doing my brain in... I can't figure out why this is happening at all! I can even ping domain names - and they resolve to their IP addresses - but no other traffic goes through! I know it's not just cached DNS values, because I'm trying sites I'd never go to - att.com, msnbc.com... they all resolve fine, i just can't ping or surf to ANYTHING and traceroutes also get nothing

Wicked_and_Crazy · 26-06-2007, 23:14

Have you got the modem connected to the WAN socket on the router and not one of the LAN sockets?

christopherw · 26-06-2007, 23:18

Yep, of course

I've just done a full reset including changing the IP ranges on the DHCP pool - the cable modem is still .100, but the router is now .101 and the DHCP range starts from .110 (and the leases are only 3 minutes to avoid clogging up the router)... it still seems that the dd-wrt box is passing every individual connection to the modem as if it was a dhcp server, even though the modem is nothing but a dumb modem - it doesn't do any dhcp assignments at all, it just assigns the public IP to whichever device is plugged into its ethernet port.

The DD-WRT router has the correct WAN IP: 82.36.88.24 (at present). It also has (seemingly) the correct details from the VM servers for its own IP assignment: gateway of 82.36.88.1, and the same three DNS servers as the next door neighbour's router assigns my laptop when I connect to their open access point.

I just, for the life of me, can't figure out why my setup isn't working, particularly when yours seems to be working fine :/

Wicked_and_Crazy · 26-06-2007, 23:28

im confused because my HCP clients are as follows, i dont see my modem in there

Network-Drive192.168.1.112
pda192.168.1.121
slave192.168.1.137
Master192.168.1.141

---------- Post added at 23:26 ---------- Previous post was at 23:22 ----------

why is your router .100? Surely it should be .1?

---------- Post added at 23:28 ---------- Previous post was at 23:26 ----------

Also are you using the same MAC address on your router and laptop at the same time?

MovedGoalPosts · 26-06-2007, 23:29

It's not normally required to clone any mac address of a connected device when on a modem - that generally applied to set top box users which had different protocols to cable modems.

What happens if you connect a different PC direct to the modem via ethernet, assuming the PC is set to auto on all it's IP, DNS and related settings (a PC that has not been connected direct to the modem before)? Remember you MUST reboot the modem (power off, rest then on).

I do believe you will have something tiny somewhere setup in your router's config that you don't need. For cable most stuff should be auto as far as the connections DNS and stuff are required. Have you any way of factory resetting, including reverting to the default Linksys firmware. Get that running then upgrade to DD-WRT. When I upgraded my Linksys WRT54GS to DD-WRT the only changes I was making then was to the connection settings (timeout stuff) for torrents, nothing else.