I have a problem i have a cisco router with the ethernet interface but our telephone line is still the two wire rj11 plug. after speaking with my ISP they have informed me tjhat they can not fit my connection with an rj45 connection and they cant run a modem to convert the the line for my cisco router what can i do to sort this out.
A line with an RJ11 sounds like a phone line, which suggests your ISP is providing an ADSL service. If that's the case you'll need an ADSL modem/router to plug into the line, so I think you have two options. Assuming your Cisco router supports it, you could get hold of an ADSL interface module and install it into the router. Or at a pinch you could maybe get hold of a separate ADSL modem/router that will give you an RJ45 ethernet output. You could then connect that into your Cisco. To advise better I think we'll need a bit more detail
we are currently running a zxl modem which has a ethernet out (lan cable) and the problem apparently is that there will be a conflict concerning domain/ip conflict this is the first time im working with a ciso router so im at a big disadvantage the Cisco router was delivered to us already set up just needed to be plugged in but if the cisco has to be plugged in to the zxl router does that mean that i would have to effect changes in the cisco set up and how ould i go about this.
Here is an older thread I started regarding setting up a cable modem/DSL modem with a Cisco router. This might give you some insight and direction.
In short, there should be no IP conflicts because the modem will have an external IP address such as 220.127.116.11 shown in my diagrams in the link above.
Second, you will be plugging into the 10/100 Ethernet port on your Cisco router which will have an internal address (Ex: 192.168.x.x).
So, being that your using DSL you will have a phone linke (RJ11) coming from the wall. The ISP will provide a connection via this RJ11, which should then plug into a modem the ISP provides. From that modem you will have 2 interfaces (phone RJ-11 and data RJ-45). You will branch off from the modem with the RJ-45 cable to the Cisco routers 10/100 Ethernet port. You will setup the appropriate addressing on the Cisco router next. That should be your flow for you to establish a connection.
Keep in mind - You have not stated the type of Cisco series router your using. But your Cisco router will need to have 2 10/100 Ethernet ports (0/0 and 0/1). Eth0 will connect to your DSL modem, and Eth1 will connect to your switch or computer.
You can't run a modem? Your ISP won't provide you with a DSL modem? An ISP won't provide DSL or Cable services without a modem. If your ISP told you they can't send you a modem, it sounds more like you have dial-up, and you will use your own 56k modem to dial out to the Internet.
The only other thing I can think of, is a modem used to dial into a router, as in a backdoor from the outside or if the network has issues/goes down.