# VDSL Cisco 575 LRE

## marrowhk

I've just moved and my new apartment is served by a Cisco 575 LRE (VDSL) rather than an ADSL modem which i have been used to using.

With my old ADSL modem connected to a broadband router, i could renew my IP quite efficiently by using the router to terminate and restart the PPPoE session. The dynamic IP would get me back on-lne with a new IP in no time.

Now, with this Cisco CPE, even though it has been setup as a dynamic IP connection via the broadband router (my ISP also assures me it is a truly dynamic connection!) I always seems to end up with the same IP!. If i clone the MAC address the IP address changes, but that's it (only two IP adresses). I tried using macchanger thinking that the IP is bound to the mac address, but that was disastrous.

Does anyone have experience with the Cisco 575 LRE (Long Reach Ethernet)? If so, how do i get it to really get me a dynamic IP address? Can you access the Cisco device like a router via a web interface (my router is configurable via the default http://192.168.0.1) 

I'm all out of ideas!   :Embarassed: 

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## loisl

Hai,

this sounds really strange.

Since this Cisco Box (which is out of sale for a while now, so it is a pretty old "beware of" device) is a pure Ethernet bridge device which bridges Ethernet frames sourced by Your Router to the VDSL line and vice versa. Even if the number of Ethernet MAC addresses it can bridge is limited it is for sure greater than one (and even one is sufficient).

My suggestion is that Your ISP has an issue with its RADIUS/DHCP server since You get a different IP address when Your Ethernet MAC changes. Somehow Your MAC/IP address combination ended up in something like a cache and You get always the same (maybe now duplicate) IP address. The RADIUS/DHCP server is the first (and only) point where a User MAC address will be combined with an dynamic IP address out of a given range.

Request Your provider to troubleshoot this more seriously.

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## marrowhk

Will do, thanks.

Note:

went back to macchanger and did the following;

1. stop eth0

2. macchanger -a eth0

3. start eth0

Now i have a fake mac and the ip address is changed! Seems to be working (i.e.,) with a bit of work i can now change my dynamic ip address!!

However, the line is a 10Mline but uploading is far bigger than downloading. I can upload at 1200kbps but download is roughly 45kbps! Is there any way to balance these out by getting into the cisco 575lre box, or the deeper cisco box behind it by telnet?

Also, i have the DLink DI 704UP router to split the connection to two PCs, but i can't telnet into the router to do any CLI scripting. I can use the GUI via http://192.168.0.1 on firefox, but i want to use autoexpect to create a script so that i can do all this ip changing and router rebooting from a script rather than having to go to the gui everytime. Most other routers i've had i have alsways been able to telnet into them, but there telnet 192.168.0.1 returns :connection refused.

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## loisl

Hai,

VDSL is an asymmetric service by definition. Here in good old Germany the ratio is about 1:5 upload:download (meaning download 25Mbps, upload 5Mbps). 

I believe there is something really messed up: 10Mbps (Megabit per second) line should result in a 1250 KB/s (Kilobyte per second) downstream. Your 45KB/s lead to a 384kbps bandwidth in the other direction. 

It seems that Your ISP has really miss configured the DSLAM port Your VDSL line ends up in. He mixed up- and downstream channels (for me it is new that this is configurable at the DSLAM. It looks as if Yor ISP does not only have an issue with RADIUS/DHCP but with more serious components as well. 

Here in Germany an ISP had an issue with its miss configured Ethernet aggregation switches. Windows XP/Vista PCs with plug-and-play enabled (default) which were directly connected to the xDSL line could see PnP Devices (Routers or PCs with PnP activated!) of other of its customers connected to the same Access Network segment. So people could fraudulently miss use those ISP connections for downloading child porns.

Your ISP has to troubleshoot Your problems!Last edited by loisl on Sun Mar 23, 2008 9:51 pm; edited 1 time in total

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## marrowhk

Will give them a call ASAP after the holidays, thanks.

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