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My ISP is forcing me to use their own router, the "Sky Hub". It has a hardcoded username/password that it sends as a Client Identifier in a DHCP request in order to be allowed an IP address.

This router is horrible, at least since the last firmware update. They released a firmware update a few months back to add IPv6 support but: (a) I want to use the HE tunnel broker to have a static IPv6 address and (b) IPv6 was not actually enabled on the ISP side yet.

The router randomly decides to destroy checksums in IP headers once in a while, causing reliability issues. With this state, if I attempt to connect to HE using 6in4, the IPv4 packets that encapsulate the IPv6 packets get broken checksums (and I am not the only one to experience it). Because of this, I can ping6, but cannot use other protocols like TCP due to extreme packet loss.

I have some possible solutions.

I can use Wireshark to listen into the DHCP packets sent by the router and obtain my username/password for DHCP, and then use a different router. The only other router I have is one provided by an older ISP, and I do not think it is possible to change the userna,e/password it sends through DHCP (NETGEAR DGN1000SP).

Another option would be to use my Linux machine for that purpose, by having a wifi card used as an access point, NAT configured with iptables, and a direct DSL connection.

The machine only has a single ethernet (RJ45) port, and no DSL (RJ11) port. However, there are cables available on the Internet where one side has a RJ11 DSL plug, and the other has a RJ45 Ethernet plug. Is it actually possible to connect the machine to DSL in this way, by perhaps using some software?

Alternatively, are there ways to work around the broken checksums on 6in4 packets?

EDIT: My ISP supports PPPoA and MER.

You have routers and you have DSL modems, and in the case of ISP-supplied hardware those functionally separate parts may be in the same box. Linux beats consumer routers in functionality and reliability, but a desktop machine doesn't come with a DSL modem (and its dialing settings), and Ethernet electronics are not the same as DSL signals, and they aren't capable of travelling the lengths that a DSL signal can, so a converter cable is a guaranteed misbuy.

I guess I was fortunate to be on the internet business early enough to get a "dumb" DSL modem where I could put just any $20 router of my choice behind.

If I connect the machine through ethernet to a DSL model, and then into the wall, will the machine have direct access to the internet (without NAT)? In this case I could configure Linux to send the DHCP authentication info (option 61) and as previously planned, configure the wifi interface with NAT to share the connection, and easily set up the 6in4 tunnel.

Also, in this case, what is the point of the RJ45-to-RJ11 cables?

mariuszp wrote:If I connect the machine through ethernet to a DSL model, and then into the wall, will the machine have direct access to the internet (without NAT)?

It depends on your modem. If the modem's a gateway, it will perform network address translation for the machine behind it. If it's a switch or a bridge (the more "dumb" kind of device), it will not; the DSL frames will be translated directly to Ethernet frames and sent to your machine. Theoretically there's no need for a modem to perform network address translation, but if the manufacturers decided to be "clever" they might well have made it a NAT (more like a single-port router really).

You'll also want to be careful, as your ISP contract may well have a term that says that you have to use their supplied hardware. Whether or not they'll be able to detect that you're not using their hardware depends on how you configure the replacement hardware - if you configure it to mimic the supplied hardware almost exactly they'll probably never notice; if you start doing weird things like tunnelling IPv6 connections and not using their own IPv6 configuration, they might notice pretty quickly. I know it seems stupid to mimic the supplied hardware when you're trying to improve on it, but you might just want to bear that in mind. (You could maybe try to mimic their hardware *and* do your own thing at the same time...)

Hi,

mariuszp wrote:My ISP is forcing me to use their own router, the "Sky Hub".

If something doesn't work for you, replace it with something that does. This applies to ISPs (and not just hardware/software alone).


Cheers,

Brendan